摘要:

Subject Index ab initio Calculations ''0 Nuclear Magnetic Resonance Study of the Rotational Motion of the Sulphate Ion in Aqueous Solution, 127 Absorption Interaction Parameters and Miscibility Limits of Poly(dimethylsi1oxane) and Dinonyl Phthalate or Squalane Determined from Studies of the Absorption of Hexane by the Binary Liquid Mixtures, 473 Hydrogen Adsorbed and Absorbed on Raney Palladium, 1955 Neutron-scattering and Volumetric Study of Acetonitrile Kinetic Hydrogen Isotope Effects in the Reaction between 2,4,6-Trinitrotoluene in 1 -Ethylpiperidine in Acetonitrile. The Effect of Pressure, 2959 Acoustic Relaxation Aqueous Solutions. Part 2.-The Compressibility and Acoustic Relaxations of Water, 1 Acrolein Tin Oxide Surfaces. Part 16.--Infrared Study of the Adsorption of Formic Acid, Acrylic Acid and Acrolein on Tin(1v) Oxide, Tin(1v) Oxidesilica and Tin(1v) Oxide-Palladium Oxide, 1345 Luminescence Quenching and Flash Photolysis Acr ylamidometh ylthionine Studies of Acrylamidomethylthionine Copolymers. 2763 Acrylic acid Tin Oxide Surfaces.Part 16.-Infrared Study of the Adsorption of Formic Acid, Acrylic Acid and Acrolein on Tin(rv) Oxide, Tin(rv) Oxide-Silica and Tin(1v) Oxide-Palladium Oxide, 1345 Activation Parameters Kinetics of the Reaction between Cyanide lons and Tris(4-methyl- 1 , 10-phenanthroline)iron(rI) Cations in Aqueous Solutions. Analysis of Kinetic Data for this Reaction and for Solvolysis of Benzyl Chloride in Water in Terms of Isothermal, Isobaric and Related Isochoric Activation Parameters, 11 Activity coefficients Cryoscopic, Infrared Spectroscopic and Dielectric Studies of Associated Cyclohexanol + Benzene Mixtures, 1 14 1 Adhesion Double-layer Interactions of Unlike Spheres.Part 2.-Numerical Analysis of Electrostatic Interaction Energy, 18 19 Adsorption Adsorption and Conductivity Studies in Oxychlorination Catalysis. Part 4.-Effect of Adsorption on the Conductivity of Copper(1) Chloride Films, 69 Linear Isotherms in Multicomponent Adsorption Effects of Surface Heterogeneity on Liquid onto Silica Gel from Organic Solvents, 185 Adsorption Chromatography with Mixed Mobile Phases, 553 Capillary-condensed Water in Silica Gel, 597 Chemisorption and Catalysis on LaMO, Oxides, Thermodynamics of Adsorption of 939 0-n-Dodecylpentaethylene Glycol and 0-n-Dodecyloctaethylene Glycol from Aqueous Solutions on to Graphitised Carbon, 1503 Ab Initio Molecular-orbital Study on the Adsorption of Ethylene and Oxygen Molecules over Vanadium Oxide Clusters, 15 13 Excess Properties and Thermodynamics of Multicomponent Gas Adsorption, 1527 Excess Properties and Column Dynamics of Multicomponent Gas Adsorption, 1541 Relaxation Processes on Graphitic Surfaces.Part 1 .--In the Absence and Presence of Adsorbed Temperature, 1589 2.-Adsorption of *He on Spheron and Grafoil, 161 I Rotational Degrees of Freedom in the Adsorption of Hydrocarbons on Aerosil, I63 1 Calculation of the Adsorption Potential of Argon ori Dehydroxylated Aerosil. 1637 Calorimetric Measurement of Heats of Vapour Adsorption on Graphitized Thermal Carbon Black, 1685 A Critique of the Adsorption Isotherms used in Electrochemical Processes involving the Adsorption of Organic Compounds, 1767 Double-layer Interactions of Unequal Spheres.Part 1 .-The Effect of Electrostatic Attraction with Particles of Like Sign of Potential, 1797 Determination of the Adsorption Behaviour of ' Overpotential-deposited ' Hydrogen-atom Species in the Cathodic Hydrogen-evolution Reaction by Analysis of Potential-relaxation Transients, 1841 Hydrogen Adsorbed and Absorbed on Raney Palladium, 1955 Molecular Diffusion in Monolayer Films of Water Adsorbed on a Silica Surface, 2067 Interaction of Carbon Monoxide with Rhodium Catalysts. Studies of Adsorption and Thermal Desorption, 2225 Non-ionic Surfactants from Aqueous Solution on to Silica, 2235 on Spheron and Grafoil with Increasing Relaxation Processes on Graphitic Surfaces.Part Neutron-scattering and Volumetric Study of Adsorption of n-Alkylpolyethylene Glycol Thermodynamic Study of Tetramethyltin, iii SUBJECT INDEX Adsorption (cont.) Sn(CH,),, Absorbed on (000 1) Graphite Planes, 2339 Adsorption of Methylamines on Dehydrated NaX, NaY and KY Zeolites, 2525 Effect of Sodium Polyacrylate on the Properties of Dilute and Concentrated BaSO, Dispersions, 2635 Magnesium Oxide, Nickel Oxide and their Solid Solutions, 1283 Pore Network Interactions in Ascending Processes Relative to Capillary Condensation, 293 1 Enthalpies of Adsorption of Non-ionic Surfactants from Aqueous Solutions on to Silica, 3109 Spectroscopic Study of NO Adsorption on Aerosil Rotational Degrees of Freedom in the Adsorption Calculation of the Adsorption Potential of Argon of Hydrocarbons on Aerosil, 163 1 on Dehydroxylated Aerosil, 1637 Alcohol Temperature-programmed Desorption Studies of Alcohol Decomposition on Zinc Oxide.Propan-2-01, 3073 Aliphatic Alchols Calorimetric Investigation of NaI-Alcohol Interactions in Alcohol + Alcohol Mixtures, 1913 Aliphatic Alcohols Dielectric Relaxation in Mixtures of N,N-Dimethylacetamide with some Aliphatic Alcohols, 397 Apparent Heat Capacities and Volumes of Linear Alcohols in Hydrocarbons, 635 Self-association of Alcohols in Inert Solvents Alkali Metals Enthalpies and Entropies of Complexation of Cryptand 222 and Metal Ions in Propylene Carbonate and Acetonitrile. Derived Thermodynamic Parameters for the Transfer of Metal-ion Cryptates, 78 1 Relationship between the Entropy of Transfer of a Solute and the Thermodynamic Functions of Mixed Solvents, 2703 Alkaline Earth Metal Comparison of the Surface Reactivity and Spectroscopy of Alkaline-earth-metal Oxides.Part 2.-Dependences upon Temperature of Pre-activation for SrO, 2027 Solute-Solvent Interactions in Water-t-Butyl Alcohol Mixtures. Part 14.-AGe, AHe and A S e of Transfer for Alkaline-earth-metal Cations, 308 1 Alkanes Liquid Structure and the Excess Volumes of Cyclohexane + Normal- and Branched-alkane Mixtures, 375 Coefficients of Cyclohexane + Normal- and Branched-alkane Mixtures, 387 Self-association of Alcohols in Inert Solvents Apparent Heat Capacities and Volumes of Linear Alcohols in Hydrocarbons, 635 Liquid Structure and the Thermal Pressure Enthalpic McMillan-Mayer Coefficients from Literature Data on Excess Enthalpies.Application to Solutions of Alkanes in Alkan- 1 -ols, 10 15 ZSM-5 Type Zeolites, 2541 Microdynamics of Methane, Ethane and Propane in Alkanols Enthalpic McMillan-Mayer Coefficients from Literature Data on Excess Enthalpies. Application to Solutions of Alkanes in Alkan-1-ols, 1015 Alk ylamines Intercalation of n-Alkylamines by a-Zirconium Phosphate. 545 Alkylpolyethylene Glycols Enthalpies of Adsorption of Non-ionic Surfactants from Aqueous Solutions on to Silica, 3 109 Alkylpyridinium Iodides Ultraviolet-Visible Spectrophotometric Determination of Ion-association Constants for Alkylpyridinium Iodides. N-Ethyl-4-cyanopyridinium Iodide in Mixed Solvents Containing Ethanol, 961 Alumina Spectroscopic Study of the Cokefaction of Butene and Butane on Alumina, 497 Insertion of Aluminium into High-silica-content Zeolite Frameworks.Part 3.-Hydrothermal Transfer cif Aluminium from A1,0, into [Al]ZSM-5 and [B]ZSM-5,2215 An In Situ Mossbauer Investigation of the Influence of Metal-Support and Metal-Metal Interactions on the Activity and Selectivity of Iron-Ruthenium Catalysts, 2293 Studies of the Effect of Calcination on the Dispersion and Reduction of Nickel Supported on Alumina by X-Ray Photoelectron Spectroscopy, X-Ray Diffraction, Chemisorption and Catalytic Activity, 2733 Infrared Spectroscopic Study of the Adsorption of CO, CO, and NO on Fluorinated Alumina and Supported Molybdenum-Nickel Catalysts, 1203 Aluminium Aluminium-27 Nuclear Magnetic Resonance Studies of the Hydrolysis of Aluminium(II1).Part 7.-Spectroscopic Evidence for the Cation [A 10Hl2 from Line-broadening Studies at High Dilution, 1923 Aluminium Perchlorate Equimolar Mixtures of Trivalent Metal Perchlorates as Constant-ionic-strength Media in Studies of Complex Formation in Dimethyl Sulphoxide. Iron(m) and Aluminium(in) Thiocyanate Complex Formation, 1037 Aluminium Sulphate Nuclear Magnetic Resonance and Molar-volume Studies of the Complex Formed between Aluminium(in) and the Sulphate Anion, 193 Aqueous Solutions Containing Amino Acids and Amino acids Peptides. Part 16.-Solute-Solute Interactions in Solutions containing some N-Acetyl-W-methylamino Acid Amides, 219 1 Aqueous Solutions Containing Amino Acids and Peptides.Part 17.-Pairwise Enthalpic... SUBJECT INDEX 111 Amino acids (cont.) Coefficients for the Interaction of N- Acetyl-L-Phenylalaninamide with some N-Acetylamino Acid Amides at 25 "C, 2207 Ammonia Adsorption and Catalytic Properties of Co,Fe,-,O, Spinels. Part 1 .-Preparation and Characterisation of Precursors to Ammonia-synthesis Catalysts, 2577 Adsorption and Catalytic Properties of Co,Fe,-,O, Spinels. Part 2.-Hydrogen Chemisorption on Precursors to Ammonia Synthesis Catalysts, 2593 Anatase Rutile Growth at the Surface of TiO, Films Deposited by Vapour-phase Decomposition of Isopropyl Titanate, 31 17 Antimony Electrical Conductivity of Uranium-Antimony Oxide Catalysts, 1121 Antimony Oxide Phase Cooperation in Oxidation Catalysis. Structural Studies of the Iron Antimonate-Antimony Oxide System, 1693 Evidence for Infrared Absorbing Electrons in Alkaline Aqueous Glasses.A Pulse-radiolysis Study at Temperatures down to 6 K, 3067 Aqueous Glasses Aqueous Solutions Aqueous Solutions. Part 3.-Thermal and Acoustic Characteristics of Water, 519 Argon Effect of Chemisorbed Water on the Two-dimensional Condensation of Water and Argon on CaF,, 757 Calculation of the Adsorption Potential of Argon on Dehydroxylated Aerosil, 1637 Autocatalysis Multistability and Sustained Oscillations in Isothermal, Open Systems. Cubic Autocatalysis and the Influence of Competitive Reactions, 1563 Ion-pair Formation as a Determining Factor in the Effectiveness of the Interaction of Electrolytes with Amphiphilic Azo Dyes in Water, 1369 Azo Dyes Barium Carbonate Study of Dispersed Solid-phase Ontogenesis using Hierarchical Structure Data, 1275 Barium Chromate Heterogeneous Oxidation of Hydrazine by Barium Chromate, 1 1 13 Barium Sulphate Effect of Sodium Polyacrylate on the Properties of Dilute and Concentrated BaSO, Dispersions.2635 Belousov-Zhabotinsky Reaction Oscillatory Phenomena in the Belousov-Zhabotinsky System. Experimental Behaviour Studied by Potentiometric Techniques, Kinetic Steps and an Explanation of the Oscillations by the D'Alba-Di Lorenzo Model, 42 1 Benzene Cryoscopic, Infrared Spectroscopic and Dielectric Studies of Associated Cyclohexanol + Benzene Mixtures, 1141 Benzo ylacetone Determination of the Rate of Tautomerization of 1 -Phenylbutane-l,3-dione (Benzoylacetone) using the Technique of Solubilization into Micelles, 294 1 Binary Mixtures Retention Volumes and Retention Times in Binary Chromatography.Determination of Equilibrium Properties, 16 1 Biphenyl Influence of External Fields on Nucleation and Crystal Growth. Crystal Growth on n-Octylbiphenyl from Solution in the Presence of Magnetic and Electromagnetic Fields, 673 Bismuth Molybdate Redox Properties of Various Bismuth Molybdate Phases in the Catalytic Oxidation of But- 1 -ene, 2107 Identification of Active Oxide Ions in a Bismuth Molybdate Selective Oxidation Catalyst, 2903 The Thermal Dissociation of Ethane. A Study of Bond Fission the Reaction over an Extended Pressure Range, 745 Boundary Layer Theory Metal-organic Chemical Vapour Deposition (MOCVD) of Compound Semiconductors.Part 1 .-Optimisation of Reactor Design of the Preparation of ZnSe, 271 1 Bromide Oxidation Kinetic Investigation of the Oxidation of Bromide Ions by Cobalt(1Ir). Part 1 .-The Influence of Pyridine in Acetic Acid Solvent, 2095 Buta- 1,3diene Hydrogenation of Buta- 1,3-diene on Supported Metal Catalysts in Aqueous Solution. Part 1 .-Differences in the Catalytic Action of Al,O,-supported Pt, Pd, Rh and Ru Catalysts, 175 Catalysis by Amorphous Metal Alloys. Part 2.-Effects of Oxygen Pretreatment on the Catalytic Activity of Amorphous and Crystallised Ni-P Alloys, 2485 n-Butane Isomerization of Alkanes on Epitaxially Oriented (1 1 1) Pd-Cu and Pd-Ag Alloy Films, 1447 Electron Spin Resonance Studies of the Radicals Formed from C-Nitroso Compounds and Olefins.Part. 3.-Reactions of Fluoro-olefins with Trifluoronitrosomethane and with 2,4,6-Tribromonitrosobenzene, 679 C-Nitroso Compounds Cadmium Ion Exchange in Zeolites. The Exchange of Cadmium and Calcium in Sodium X Using Different Anionic Backgrounds, 173 1 Cadmium Gallium Oxide Structural Characterization of Cadmium-Copper Gallium Oxide (Cd,Cu,-,Ga,O,) Spinels, 1255 Cadmium Qxalate Determination of Stability Constants using Linear-scan and Cyclic Voltammograms, 2659 Time-resolved Photoredox Reactions of Colloidal Cadmium Sulphide CdS, 1999iv SUBJECT INDEX Calcium Ion Exchange in Zeolites. The Exchange of Cadmium and Calcium in Sodium X Using Different Anionic Backgrounds, 173 1 Calcium Difluoride Effect of Chemisorbed Water on the Two-dimensional Condensation of Water and Argon on CaF,, 757 Calorimetry Calorimetric Investigations on Association in Ternary Systems. Part.3.-Hydrogen-bonded Complexes in Phenol-Tetrahydrofuran Systems in CCl,, 695 Calorimetric Measurement of Heats of Vapour Adsorption on Graphitized Thermal Carbon Black, 1685 Interactions in Alcohol + Alcohol Mixtures, 19 13 Peptides. Part 16.-Solute-Solute Interactions in Solutions containing some N-Acetyl-N-methylamino Acid Amides, 2 19 1 Aqueous Solutions Containing Amino Acids and Peptides. Part 17.-Pairwise Enthalpic Coefficients for the Interaction of N-Acetyl-L-Phenylalaninamide with some N-Acetylamino Acid Amides at 25 "C, 2207 Heat Capacities of Water + Organic-solvent Mixtures, 2381 Molecular Structure and Orientational Order Effects in Enthalpies and Heat Capacities of Solute Transfer into n-Hexadecane.Part 2.-Cyclic and Aromatic Solutes, 3037 General Trends in Phase Transitions in an Homologous Series. Polymorphism in (n-C,H,,NH,),MnCl, as Determined by Adiabatic Calorimetry from 18 to 3 13 K, 3059 Calorimetric Investigation of NaI-Alcohol Aqueous Solutions Containing Amino Acids and Capillary Phenomena Capillary-condensed Water in Silica Gel, 597 Capillary Phenomena, 9 19 Effect of Pore Structure and Macroscopic Non-homogeneity on the Relative Gas Permeability of Porous Solids, 1 183 Relative to Capillary Condensation, 293 1 Pore Network Interactions in Ascending Processes Carbon Hydrogen Sorption by a Supersaturated Solution of Carbon in Palladium, 28 13 Carbon Dioxide Carbon Dioxide-mediated Decomposition of Hydrogen Peroxide in Alkaline Solutions, 1 13 Carbon Fibre X-Ray Photoelectron-spectroscopic Studies of Carbon-fibre Surfaces.Part 5.-The Effect of pH on Surface Oxidation, 2745 Carbon Monoxide Infrared Spectroscopic Study of the Adsorption of Hydrogen and Carbon Monoxide on Highly Dehydroxylated Thoria, 2 15 Conversion of Carbon Monoxide into Methanol at Room Temperature and Atmospheric Pressure, 267 Reduction of Carbon Monoxide on a Mediated and Partially Immersed Electrode, 1569 Interaction of Carbon Monoxide with Rhodium Catalysts. Studies of Adsorption and Termal Desorption, 2225 An In Situ Mossbauer Investigation of the Influence of Metal-Support and Metal-Metal Interactions on the Activity and Selectivity of Iron-Ruthenium Catalysts, 2293 Spectroscopic Characterization of a Molybdena/Silica System Photoreduced in a Carbon Monoxide Atmosphere, 2307 Hydrogenation of Carbon Monoxide on PLmorphous Fe8,B13.sSi3.sC2.Activity and Segregational Behaviour of the Alloy, 2797 Carbon Monoxide Chemisorption on a Pt-NaY Catalyst. Part 1 .-Determination of the Distribution of the Chemisorbed Carbon Monoxide Phase by a 129Xe-N~clear Magnetic Resonance Study of Adsorbed Xenon, 2855 Carbon Monoxide Chemisorption on a Pt-NaY Catalyst. Part 2.-Influence of Carbon Monoxide Coverage and of Coadsorbed Molecules on the Infrared Spectrum of Adsorbed Carbon Monoxide (Electron Transfer and Dipole-Dipole Coupling), 2867 Carbon Tetrachloride Isotopic Effects on the Tracer Diffusion of Water, Methanol and Ethanol Dissolved in Carbon Tetrachloride at 25 "C, 103 1 Catalase Reaction of Catalase with Ethylhydrogen Peroxide, 91 Catalysis Study of Methanol and Water Chemisorbed on Molybdenum Oxide, 19 Characterization of Silica-supported Vanadium Species.Interactions with Methanol and Ammonia Adsorbates Studied by Electron Spin-Echo Modulation Spectrometry, 137 Hydrogenation of Buta- 1,3-diene on Supported Metal Catalysts in Aqueous Solution. Part 1 .-Differences in the Catalytic Action of Al,O,-supported Pt, Pd, Rh and Ru Catalysts, 175 Conversion of Carbon Monoxide into Methanol at Room Temperature and Atmospheric Pressure, 267 X-Ray Scattering Structural Investigation of Pt and Pt-Sn Catalysts Supported on Nylon, 321 Spectroscopic Study of the Cokefaction of Butene and Butane on Alumina, 497 Measurement of the Activity of Hydrogen and Oxygen Catalysts by a Photochemical Relaxation Method, 601 Chemisorption and Catalysis on LaMO, Oxides, 939 Surface Characterization of a Grafted Vanadium-Titanum Dioxide Catalyst, 1003 Binding and Decomposition of Oxovanadium(1v) Phthalocyanine, Tetraphenylporphyrin and Etioprophyrin on Hydrotreating Catalysts Studied by X-Ray Photoelectron and Ultraviolet-Visible Spectroscopies.Relevance to Catalytic Demetallisation, 1047SUBJECT INDEX V Catalysis (cont.) Characterization of Sulphided Molybdenum-containing Hydroprocessing Catalysts by Oxygen and Hydrogen Chemisorption, 1655 Structural Studies of the Iron Antimonate-Antimony Oxide System, 1693 Activity of Supported Tungsten Oxide Catalysts for the Metathesis of Propene, 1705 Electrical-conductance Responses of Catalysts Exposed to Pulses of H, and 0,, 17 15 Exchange Reactions of Hydrocarbons on Silica-supported Rh-Pt Bimetallic Catalysts, 187 1 Comparison of the Surface Reactivity and Spectroscopy of Alkaline-earth-metal Oxides.Part 2.-Dependences upon Temperature of Pre-activation for SrO, 2027 Decomposition of N,O on Fe,O,/Al,O, Catalysts. Relationship between Physicochemical and Catalytic Properties, 2043 of Propene on ZnO using l80,, 2409 2.-Effects of Oxygen Pretreatment on the Catalytic Activity of Amorphous and Crystallised Ni-P Alloys, 2485 Spinels. Part 1 .-Preparation and Characterisation of Precursors to Ammonia-synthesis Catalysts, 2577 Adsorption and Catalytic Properties of Co,Fe,-,O, Spinels. Part 2.-Hydrogen Chemisorption on Precursors to Ammonia Synthesis Catalysts.2593 Aspects of Temperature-programmed Analysis of some Gas-Solid Reactions. Part 1 .-Dispersion Effects in Temperature-programmed Bulk Reduction and Temperature-programmed Desorption, 2605 Carbon Monoxide Chemisorption on a Pt-NaY Catalyst. Part I .-Determination of the Distribution of the Chemisorbed Carbon Monoxide Phase by a 129Xe-N~clear Magnetic Resonance Study of Adsorbed Xenon, 2855 Carbon Monoxide Chemisorption on a Pt-NaY Catalyst. Part 2.-Influence of Carbon Monoxide Coverage and of Coadsorbed Molecules on the Infrared Spectrum of Adsorbed Carbon Monoxide (Electron Transfer and Dipole-Dipole Coupling), 2867 Identification of Active Oxide Ions in a Bismuth Molybdate Selective Oxidation Catalyst, 2903 Infrared Spectroscopic Study of the Adsorption of CO, CO, and NO on Fluorinated Alumina and Supported Molybdenum-Nickel Catalysts, 1203 Crystal Planes, 298 1 Phase Cooperation in Oxidation Catalysis.Infrared Studies of Intermediates in the Oxidation Catalysis by Amorphous Metal Alloys. Part Adsorption and Catalytic Properties of Co,Fe, Decomposition of Nitrous Oxide on Palladium Catalysts Electrical Conductivity of Uranium-Antimony Oxide Catalysts, 1 I2 1 Catalytic Cracking The Catalytic Cracking of Cumene Stidied by Reversed-flow Gas Chromatography, 95 1 A Shape-selective Platinum-loaded Mordenite Catalyst for the Hydrocracking of Paraffins by the Chemical Vapour Deposition of Silicon Alkoxide, 2757 Fluorine, 1 16 I Catalytic Oxidation Catalytic Properties of H Mordenite Modified with Redox Properties of Various Bismuth Molybdate Phases in the Catalytic Oxidation of But-1 -em, 2107 Cellulose Photochemistry of Compounds Adsorbed into Cellulose.Part 4.-Diffusion-controiled Mechanism of Ru(bpy)z+ Luminscence Quenching by Copper(II), 735 Cerium Kinetics of the Oxidqtion of Substrate Ligands by Transition-metal Cations. The Oxidation of Iodide Ions by Aquacations, 801 Cetyltrimethylammonium Structural Study of Microemulsions of Glycerol Stabilised by Cetyltrimethylammonium Bromide Dispersed in Heptane + Chloroform Mixtures, 2053 Cetyltrimethylammonium Bromide Binding of 2-Naphtholate Ions to a Water-in-oil Cetyltrimethylammonium Bromide Microemulsion. The Enthalpy and Entropy of Interaction, 2723 Chabazites Deammoniation and Dehydroxylation of Calcium Ammonium Chabazites, 3049 Charge Transfer Effects of Pressure on Charge Transport in Protein Powders.1939 Chemical Equilibrium Partial Molar Isobaric Heat Capacities of a Substance in a System containing a Chemical Equilibrium. A Basis for the Estimation of the Effect of Solvent Reorganisation on Heat Capacities of Activation for Chemical Reaction, 1495 Chemical Potential Temperature Dependence of the Chemical Potential of Hydrogen in the Two-phase Coexistence Region of the Palladium-Hydrogen System, 292 1 Chemical Vapour Deposition Metal-organic Chemical Vapour Deposition (MOCVD) of Compound Semiconductors. Part 1.-Optimisation of Reactor Design of the Preparation of ZnSe, 27 1 1 Chemical Vapour Transport Preparation, Characterization and Photoelectronic Properties of Germanium-substituted Fe,O, Single Crystals, 1263 Chemisorption Effect of Oxide Thickness on the Rates of some Effect of Chemisorbed Water on the Redox Reactions on a Platinum Electrode, 403 Two-dimensional Condensation of Water and Argon on CaF,, 757 Adsorption and Catalytic Properties of Co,Fe,-,O, Spinels.Part 2.-Hydrogen Chemisorption on Precursors to Ammonia Synthesis Catalysts, 2593v1 SUBJECT INDEX Chemisorption (cont.) Studies of the Effect of Calcination on the Dispersion and Reduction of Nickel Supported on Alumina by X-Ray Photoelectron Spectroscopy, X-Ray Diffraction, Chemisorption and Catalytic Activity, 2733 Catalyst. Part 1.-Determination of the Distribution of the Chemisorbed Carbon Monoxide Phase by a 1*9Xe-N~clear Magnetic Resonance Study of Adsorbed Xenon, 2855 Carbon Monoxide Chemisorption on a Pt-NaY Catalyst.Part 2.4nfluence of Carbon Monoxide Coverage and of Coadsorbed Molecules on the Infrared Spectrum of Adsorbed Carbon Monoxide (Electron Transfer and Dipole-Dipole Coupling), 2867 Carbon Monoxide Chemisorption on a Pt-NaY Chirospecificit y Sorption-Diffusion in Heterogeneous Systems. Part 9.'. -Kinetic and Thermodynamic Effects Determining the Enantio-differentiating Chirospecificity of Solid-bound Chiral Phosphine Oxides, 2273 Chloralkanes Alkyl-radical-Chloride-ion Adducts Formed in the Radiolysis of Chloroalkanes. An Electron Spin Resonance Study, 1095 Chloranil Electrical Properties of the Perylene-p-Chloranil Complex and the Effect of o-Chloranil as an Impurity, 537 Chlorobenzoic Acid 35Cl Nuclear Quadrupole Resonance Studies of Hydrogen Bonding in Solid Complexes of Chlorobenzoic Acids with Amines, 3 1 1 Cholesterol Thermodynamics of Cholesterol Self-association and its Interaction with Tripalmitin and L-a-Lecithin, 655 Chromatography Retention Volumes and Retention Times in Binary Chromatography.Determination of Equilibrium Properties, 161 Adsorption Chromatography with Mixed Mobile Phases, 553 The Catalytic Cracking of €umene Stidied by Reversed-flow Gas Chromatography, 95 1 Effects of Surface Heterogeneity on Liquid Coagulation Measurement of Coagulation Rate Constants using Number-fluctuation Spectroscopy, 285 Coal Solvent-induced Changes in the Visible Transmission Spectrum of Illiois no.6 Coal. Enhancement of Light Transmission through a Microporous Solid by Solvent-induced Index Matching of the Pores, 991 Cobalt(ii:) Kinetic Investigation of the Oxidation of Bromide Ions by Cobalt(rii). Part 1 .-The Influence of Pyridine in Acetic Acid Solvent, 2095 trans-Dichlorobis( 1,2-diarninoethane)cobalt(i11) Ion in Water+ t-Butyl Alcohol Mixtures, 2475 Kinetics of the Solvolysis of the Reactions of Cobalt(II1) Compounds with some Adsorption and Catalytic Properties of Co,Fe,_,O, Free Radicals Derived from Uracil, 2569 Spinels. Part 1 .-Preparation and Characterisation of Precursors to Ammonia-synthesis Catalysts, 2577 Adsorption and Catalytic Properties of Co,Fe,_,O, Spinels. Part 2.-Hydrogen Chemisorption on Precursors to Ammonia Synthesis Catalysts, 2593 Salt Effects in an Outer-sphere Reaction between Cations, 2967 Cobalt Complexes Separation of the Effect of Solvent Structure on the Kinetics of Substitution Reactions into Contributions to the Initial and Transition States using Free Energies of Transfer.Kinetics of the Solvolysis of 1,2-Chlorothiocyanatobis( 1,2-diaminoethane)- cobalt(iI1) Ions in Water and Water + Propan-2-01 Mixtures, 1401 Cobalt Oxide Electron Spin Resonance Spectroscopy of Surface Species formed upon Adsorption of Nitrogen Oxides and Oxygen on High-surface-area NiO-MgO and Co@MgO Solid Solutions, 37 Surface Reduction of some Transition-metal Oxide. An X-ray Photoelectron Spectroscopic Study of Iron, Cobalt, Nickel and Zinc Oxides, 21 79 Coke Formation Spectroscopic Study of the Cokefaction of Butene and Butane on Alumina, 497 Colloids Photoelectrochemistry in Colloidal Systems.Part 2.-A Photogalvanic Cell Based on TiO, Semiconductor Colloid, 509 Time-resolved Photoredox Reactions of Colloidal CdS, 1999 Small-angle Neutron-scattering Studies of Silica Sols in Water at High Temperatures, 2845 Complex Formation Nuclear Magnetic Resonance and Molar-volume Studies of the Complex Formed between Aluminium(m) and the Sulphate Anion, 193 Calorimetric Investigations on Association in Ternary Systems. Part. 3.-Hydrogen-bonded Complexes in Phenol-Tetrahydrofuran Systems in CCl,, 695 Enthalpies and Entropies of Complexation of Cryptand 222 and Metal Ions in Propylene Carbonate and Acetonitrile. Derived Thermodynamic Parameters for the Transfer of Metal-ion Cryptates.78 1 Perchlorates as Constant-ionic-strength Media in Studies of Complex Formation in Dimethyl Sulphoxide. Iron(iii) and Aluminium(ii1) Thiocyanate Complex Formation, 1037 2-Hydroxy-2-methylpropanoic Acid by Silver(i1) Ions Complexed with 2,2'-Bipyridine in Aqueous Nitrate Media, 10057 Proton Polarizability of the Hydrogen Bonds in Trifluoroacetic Acid + Pyridine-N-Oxide Systems Equimolar Mixtures of Trivalent Metal Kinetics of the Oxidation of Broad Single-minimum Proton Potential andSUBJECT INDEX vii Complex Formation (cont.) as a Function of Donor and Acceptor properties and Environment. Infrared Studies, 1425 Conductance Measurements Preferential Solvation of Ions in Mixed Solvents. Part 4.-Preferential Solvation of Cu+ in Acetone + Acetonitrile and N,N-Dimethylacetamide + Acetonitrile Mixtures Using Conductance Measurements, 687 Electrical-conductance Responses of Catalysts Exposed to Pulses of H, and 0,, 17 15 Stability Constants and Free Energies of Complexation of Metal-ion Cryptates in Nitromethane.Derived Parameters for the Extraction of Cations by Cryptand 222 from Water to Pure Nitromethane, 2495 Adsorption and Conductivity Studies in Conductivity Oxychlorination Catalysis. Part 4.-Effect of Adsorption on the Conductivity of Copper(1) Chloride Films, 69 Effects of Pressure on Charge Transport in Protein Powders, 1939 Electrical Conductivity of Uranium-Antimony Oxide Catalysts, 1 12 1 Coordination Complexes Molten-sait Hydrate Media. Cobalt(I1) Ions in ZnC1, + H,O and CaC1, + H,O Systems, 265 Preferential Solvation of Ions in Mixed Solvents.Copper Part 4.-Preferential Solvation of Cut in Acetone + Acetonitrile and N,N-Dimethylacctamide -I- Acetonitrile Mixtures Using Conductance Measurements, 687 Cellulose. Part 4.-Diffusion-controlled Mechanism of Ru(bpy)i+ Luminscence Quenching by Copper(II), 735 Photochemistry of Compounds Adsorbed into Copper(1) Chloride Adsorption and Conductivity Studies in Oxychlorination Catalysis. Part 4.-Effect of Adsorption on the Conductivity of Copper(1) Chloride Films, 69 Oxychlorination Catalysis. Part 5.-Temperature-programmed Desorption, 83 Adsorption and Conductivity Studies in Copper Electrodes Chemical Origins of Surface-enhanced Raman Scattering by Cyanide on Copper Electrodes, 2123 Copper Gallium Oxide Structural Characterization of Cadmium-Copper Gallium Oxide (Cd,Cu,-,Ga,O,) Spinels, 1255 Cryptand 21 1 A Nuclear Magnetic Resonance Study of the Sodium Cryptate Formed by 4,7,13,18-Tetraoxa-1,10- diazabicyclo[8.5.Sleicosane (C211) in Various Solvents, 1623 Complexation of Metal-ion Cryptates in Nitromethane. Derived Parameters for the Extraction of Cations by Cryptand 222 from Water to Pure Nitromethane, 2495 Stability Constants and Free Energies of Cryptand 222 Enthalpies and Entropies of Complexation of Cryptand 222 and Metal Ions in Propylene Carbonate and Acetonitrile. Derived Thermodynamic Parameters for the Transfer of Metal-ion Cryptates, 781 Crystal Growth Influence of External Fields on Nucleation and Crystal Growth. Crystal Growth on n-Octylbiphenyl from Solution in the Presence of Magnetic and Electromagnetic Fields, 673 Processing of Materials, 2787 Deposited by Vapour-phase Decomposition of Isopropyl Titanate, 3 1 17 A Liquid-bridge Model for the Float-zone Rutile Growth at the Surface of TiO, Films Crystal Structure Study of the Crystal and Molecular Structure of the 9-Cyanoanthracene trans Dimer and of its Monomerisation, 857 Crystallization Crystallization Field of Zeolite T at 100 "C for a SiO,/Al,O, Ratio of 28 and Crystallization Sequences in the Na,O-K,O-SiO,-Al,O,-H,O System, 1297 Cr ystolysis The Thermal Decomposition in the Solid Phase (Crystolysis) of Silver Malonate, 2503 Cumene The Catalytic Cracking of Cumene Stidied by Reversed-flow Gas Chromatography, 95 1 Catalytic Properties of H Mordenite Modified with Fluorine, 1161 C yanoanthracene Study of the Crystal and Molecular Structure of the 9-Cyanoanthracene trans Dimer and of its Monomerisation, 857 Cyclic Voltammetry Electrochemical Reduction of Bicarbonate Ions at a Determination of Stability Constants using Bright Palladium Cathode, 7 13 Linear-scan and Cyclic Voltammograms, 2659 Electrochemical Measurements in the Solvents Hexamethylphosphoric Triamide and Hexamethylthiophosphoric Triamide, 2875 Cyclodextrin The Inclusion of Haloperidol and Trifluperidol by a- and y-Cyclodextrins A I9F Nuclear Magnetic Resonance Study, 1247 Cyclohexane Liquid Structure and the Excess Volumes of Cyclohexane + Normal- and Branched-alkane Mixtures, 375 Coefficients of Cyclohexane + Normal- and Branched-alkane Mixtures, 387 Thermodynamics of Ethanol at Low Concentrations in Mixtures of Cyclohexane and 1,4-Dimethylbenzene, I459 Liquid Structure and the Thermal Pressure Cyclokexanol Cryoscopic, Infrared Spectroscopic and Dielectric Studies of Associated Cyclohexanol + Benzene Mixtures, 1141...Vlll SUBJECT INDEX C yclopropanes Kinetics of the Gas-phase Thermal Decompositions of 1 -Methoxy- 1 -methylcyclopropane and cis- and trans- 1 -Methoxy-2-methylcyclopropane, 14 15 Dehydration of Sodium Carbonate Monohydrate, Dehydration 1761 Dehydrogenation Photocatalytic Dehydrogenation of Aliphatic Alcohols by Aqueous Suspensions of Platinized Titanium Dioxide, 2467 Dialysis Influence of Cationic Polyelectrolytes on the Kinetics and Equilibria in Pentacyanoiron(I1) Systems, 3021 Diazabenzene Structures of Diazabenzene Cations formed by Radiolysis.An Electron Spin Resonance Study. 727 Dielectric Properties Dielectric Relaxation in Mixtures of NNDimethylacetamide with some Aliphatic Alcohols, 397 Electrical Properties of the Perylene-p-Chloranil Complex and the Effect of o-Chloranil as an Impurity, 537 Relaxation Investigations of Water Sorbed by Spherisorb Silica, 847 Differential Thermal Analysis Nuclear Magnetic Resonance and Dielectric Solid-Solid Phase Transitions in K,Cr,Oi at Pressures below 0.4 GPa from Differential Thermal Analysis under Hydrostatic Pressure, 1789 Diffusion Isotopic Effects on the Tracer Diffusion of Water, Methanol and Ethanol Dissolved in Carbon Tetrachloride at 25 "C, 1031 Frictional Formalism of Non-equilibrium Thermodynamics, 1725 Molecular Diffusion in Monolayer Films of Water Adsorbed on a Silica Surface, 2067 Hydrogen Detection in Ruthenium Oxide Layers by means of the 1H(15N,ay)'2C Nuclear Reaction, 2995 Concentration Dependence of Fickian Diffusivity in Solutions and Sorption Systems, 3103 Measurements of Volume Changes on the Mutual Diffusion and Self-diffusion in the Dilatometry Formation of Precipitates of Carbonates and Phosphates of Cadmium(i1) and Calcium(ii) in Aqueous Solutions, 2333 Dimethyl Sulphoxide Equimolar Mixtures of Trivalent Metal Perchlorates as Constant-ionic-strength Media in Studies of Complex Formation in Dimethyl Sulphoxide.Iron(i1r) and Aluminium(II1) Thiocyanate Complex Formation, 1037 Thermodynamic Functions for the Transfer of I-Naphthoic Acid from Water t o Mixed Aqueous Solvents at 298 K, 1555 Dimethylbenzene Thermodynamics of Ethanol at Low Concentrations in Mixtures of Cyclohexane and 1,4-Dimethylbenzene, 1459 Dimeth ylformamide Thermodynamic Functions for the Transfer of 1-Naphthoic Acid from Water to Mixed Aqueous Solvents at 298 K, 1555 N-Methylformamide and N,N-Dimethylformamide at Temperatures from 240 to 313 K and Pressures up to 300 MPa, 282 1 Dinitrobenzene Self-diffusion and Volumetric Measurements for Formation of the m-Dinitrobenzene Radical-anion Dimer in the Triplet Ground State on Magnesium Oxide, 1755 Discharge-flow System Rate Constants for the Reactions of Hydroxyl Radicals with Propane and Ethane, 259 Disc-Ring Electrode The Rotating Optical Disc-Ring Electrode.Part 1 .--Collection of a Stable Photoproduct, 2647 Deuterium Isotope Effect in Concentrated Aqueous Solutions.A Potentiometric and 13C Nuclear Magnetic Resonance Study of Acid Dissociation Constants, 1483 Dissociation constants Dissolution Kinetics Constant-composition Study of the Kinetics of the Dissolution of Strontium Fluoride in Aqueous Solution, 1833 Dodecy lpolyethylene glycols Thermodynamics of Adsorption of 0-n-Dodecylpentaethylene Glycol and 0-n-Dodecyloctaethylene Glycol from Aqueous Solutions on to Graphitised Carbon, 1503 p-Doping of (CH), to the Metallic Regime with Doping Gaseous Oxygen. Application to Oxygen Fuel-cell-type Electrodes, 105 Double-layer Interactions Double-layer Interactions of Unequal Spheres. Part 1 .--The Effect of Electrostatic Attraction with Particles of Like Sign of Potential, 1797 Double-layer Interactions of Unlike Spheres.Part 2.---Numerical Analysis of Electrostatic Interaction Energy, 18 19 Electric Fields Influence of External Fields on Nucleation and Crystal Growth. Crystal Growth on n-Octylbiphenyl from Solution in the Presence of Magnetic and Electromagnetic Fields, 673 Double-layer Interactions of Unequal Spheres. Part 1 .-The Effect of Electrostatic Attraction with Particles of Like Sign of Potential, 1797 Double-layer Interactions of Unlike Spheres. Part 2. - Numerical Analysis of Electrostatic Interaction Energy, 18 19 Electrical Conductivity Electrical Properties of the Perylene-p-Chloranil Complex and the Effect of o-Chloranil as an Lmpurity, 537 Electrochemistry Effect of Oxide Thickness on the Rates of some Redox Reactions on a Platinum Electrode, 403SUBJECT INDEX ix Electrochemistry (cont.) Electrochemical and Surface X-ray Photoelectron Spectroscopy Study on the Rhodium-Carbonate Electrode in Molten Nitrates, 621 A Critique of the Adsorption Isotherms used in Electrochemical Processes involving the Adsorption of Organic Compounds, 1767 Determination of the Adsorption Behaviour of Overpotential-deposited ' Hydrogen-atom Species in the Cathodic Hydrogen-evolution Reaction by Analysis of Potential-relaxation Transients, 184 1 Some Relationships Involved in the Variation of Electrochemical Gas-sensor Currents with Gas-sample Flow Rates, 1863 Electrochemical Measurements in the Solvents Hexamethylphosphoric Triamide and Hexamethylthiophosphoric Triamide, 2875 Electrodes Electrochemical and Surface X-ray Photoelectron Spectroscopy Study on the Rhodium-Carbonate Electrode in Molten Nitrates, 621 Electrochemical Reduction of Bicarbonate Ions at a Bright Palladium Cathode, 7 13 Reduction of Carbon Monoxide on a Mediated and Partially Immersed Electrode, 1569 Electrokinetics Concentration Dependence of Electrokinetic Transport Coefficients of Non-aqueous Binary Mixtures through Weakly Charged Porous Plugs, 609 Electrolytes Ion-pair Formation as a Determining Factor in the Effectiveness of the Interaction of Electrolytes with Amphiphilic Azo Dyes in Water, 1369 Electron microscopy Adsorption of n-Alkylpolyethylene Glycol Non-ionic Surfactants from Aqueous Solution on to Silica, 2235 (Crystolysis) of Silver Malonate, 2503 Hierarchical Structure Data.1275 The Thermal Decomposition in the Solid Phase Study of Dispersed Solid-phase Ontogenesis using Electron Spin-echo Spectroscopy Electron Spin Resonance and Electron Spin-echo Spectroscopic Studies of Supported-mol ybdenum Catalysts. Interaction between Molybdenum. Adsorbate and Oxygen Molecules, 3083 Characterization of Silica-supported Vanadium Species. Interactions with Methanol and Ammonia Adsorbates Studied by Electron Spin-Echo Modulation Spectrometry, 137 Electron Spin Resonance Spectroscopy Electron Spin Resonance Spectroscopy of Surface Species formed upon Adsorption of Nitrogen Oxides and Oxygen on High-surface-area NiO-MgO and COO-MgO Solid Solutions, 37 Radiolytic Preparation of Radical Cations of Nitroalkanes and Related Compounds, 565 Electron Spin Rcsonsnce Studies of the Radicals Formed from C-Nitroso Compounds and Olefins.P:irt. 3.---Reactions of F!uoro-olefins with Trifluoronitrosomethane and with 2,4,6-Tribromonitrosobenzene, 679 Radiolysis. An Electron Spin Resonance Study, 727 Formation and Stability of Ru"' Incorporated in TiO, (Rutile), 813 Alkyl-radical-Chloride-ion Adducts Formed in the Radiolysis of Chloroalkanes. An Electron Spin Resonance Study, 1095 Kinetic Electron Spin Resonance Investigation of the Monohydronitro Free Radical of 2,3,5,6-Tetrachloronitrobenzene, 1467 Dimer in the Triplet Ground State on Magnesium Oxide, 1755 Reactions of Sulphate, Phosphate and Hydroxyi Radicals with Furan. An Electron Spin Resonance Investigation in Solution, 1979 Electron Spin Resonance and Electron Spin-echo Spectroscopic Studies of Supported-molybdenum Catalysts.Interaction between Molybdenum, Adsorbate and Oxygen Molecules, 2083 Oxygen Species Adsorbed on Ultraviolet-irradiated Magnesium Oxide, 2835 Electron Spin Resonance Studies of the Radicals formed from C-Nitroso Compounds and Olefins. Part 4.-Reactions of Alicyclic Olefins with C-Nitroso Compounds, 12 15 Structures of Diazabenzene Cations formed by Formation of the rn-Dinitrobenzene Radical-anion Electron Transfer Electron Transfer and Dimerization of Viologen Radicals on Colloidal TiO,. 143 The Electronic Factor for Outer-sphere Electron-transfer Reactions, I 153 Enthalpies of Mixing Enthalpy and Volume Changes on Mixing Diethylene Glycol Di-n-alkyl Ethers with Diethylene Glycol Dimethyl Ether or n-Alkanes, 223 Enzymes Reaction of Catalase with Ethylhydrogen Peroxide, Measurement of the Activity of Hydrogen and 91 Oxygen Catalysts by a Photochemical Relaxation Method, 601 Equilibrium Properties Retention Volumes and Retention Times in Binary Chromatography.Determination of Equilibrium Properties, 16 1 ESCA Spectroscopy Catalysis by Amorphous Metal Alloys. Part 2.-Effects of Oxygen Pretreatment on the Catalytic Activity of Amorphous and Crystallised NI--P Alloys, 2485 Ethane Rate Constants for the Reactions of Hydroxyl The Thermal Dissociation of Ethane. A Study of Radicals with Propane and Ethane, 259 the Reaction over an Extended Pressure Range, 745 Tin Oxide Surfaces. Part 14.-Infrared Study of the Adsorption of Ethane and Ethenc on Tin(iv) Oxide, Tin(1v) Oxide-Silica and Tin(1v) Oxide- Palladium Oxide, I3 1 1X SUBJECT INDEX Ethanol Self-diffusion in Monohydric Alcohols under Pressure. Methanol, Methan(2H)ol and Ethanol, 769 Isotopic Effects on the Tracer Diffusion of Water, Methanol and Ethanol Dissolved in Carbon Tetrachloride at 25 “C, 103 1 Concentrations in Mixtures of Cyclohexane and 1,4-DimethyIbenzene, 1459 Thermodynamics of Ethanol at Low Ethene Tin Oxide Surfaces.Part 14.-Infrared Study of the Adsorption of Ethane and Ethene on Tin(rv) Oxide, Tin(iv) Oxide-Silica and Tin(1v) Oxide-Palladium Oxide, 13 1 1 Ethers Enthalpy and Volume Changes on Mixing Diethylene Glycol Di-n -alkyl Ethers with Diethylene Glycol Dimethyl Ether or n-A!kanes, 223 Ethylene Catalysis by Amorphous Metal Alloys. Part 2.-Effects of Oxygen Pretreatment on the Catalytic Activity of Amorphous and Crystallised Ni-P Alloys, 2485 Ethylhydrogen Peroxide Reaction of Catalase with Ethylhydrogen Peroxide, 91 Eth ylpiperidine Kinetic Hydrogen Isotope Effects in the Reaction between 2,4,6-Trinitrotoluene in 1 -Ethylpiperidine in Acetonitrile.The Effect of Pressure, 2959 Everitt’s Salt Conversion of Carbon Monoxide into Methanol at Room Temperature and Atmospheric Pressure, 267 Reduction of Carbon Monoxide on a Mediated and Partially Immersed Electrode, 1 569 Excess Volumes Liquid Structure and the Excess Volumes of Cyclohexane + Normal- and Branched-alkane Mixtures, 375 Exchange Reactions Exchange Reactions of Hydrocarbons on Silica-supported Rh-Pt Bimetallic Catalysts, 187 1 Fatty Acids Spreading Pressires for Fatty-acid Crystals at the Air/Water Interface, 973 Faujasites Infrared Spectroscopic Investigation of Preparation of High-silica Faujasites by Treatment Hydroxy-group Siting in H Faujasites, 2257 with Silicon Tetrachloride, 2889 Fickian Diffusivity Concentration Dependence of Fickian Diffusivity in Solutions and Sorption Systems, 3 103 Flash Photoiysis Luminescence Quenching and Flash Photolysis Studies of Acrylamidomethylthionine Copolymers, 2763 Float Zone A Liquid-bridge Model for the Float-zone Processing of Materials, 2787 Fluid Bridges Fluorescence Quenching Capillary Phenomena, 9 19 Investigations of the Dynamic Behaviour of Counterions of Anionic Micellar Systems by Fluorescence Quenching Experiments, 245 Photphysics of the Excited Uranyl Ion in Aqueous Solutions.Part 5.-Fluorescence Quenching by Micellar Solutions of Triton X- 100, 189 1 Studies of Acrylamidomethylthionine Copolymers, 2763 Luminescence Quenching and Flash Photolysis Fluoro-olefins Electron Spin Resonance Studies of the Radicals Formed from C-Nitroso Compounds and Olefins. Part. 3.-Reactions of Fluoro-olefins with Trifluoronitrosomethane and with 2,4,6-Tribromonitrosobenzene, 679 Formic Acid Tin Oxide Surfaces. Part 16.--Infrared Study of the Adsorption of Formic Acid, Acrylic Acid and Acrolein on Tin(1v) Oxide, Tin(rv) Oxide-Silica and Tin(rv) Oxide-Palladium Oxide, 1345 Interactions between Metal-complex Ions and Water. Part 2.-Osmotic and Mean Activity Coefficients of Trivalent Metal Complex Chlorides in Aqueous Solutions at their Freezing Points, 2805 Freezing-point Depression Fuel Cells p-Doping of (CH), to the Metallic Regime with Gaseous Oxygen.Application to Oxygen Fuel-cell-type Electrodes, 105 Furan Reactions of Sulphate, Phosphate and Hydroxy Radicals with Furan. An Electron Spin Resonance Investigation in Solution, 1979 Gas Permeability Effect of Pore Structure and Macroscopic Non-homogeneity on the Relative Gas Permeability of Porous Solids, 1183 Gas Sensors Some Relationships Involved in the Variation of Electrochemical Gas-sensor Currents with Gas-sample Flow Rates, 1863 Gaseous Oxidation Reactions A Thermokinetic Foundation for Oscillatory Phenomena in Gaseous Organic Oxidations under Well Stirred Flowing Conditions, 343 The Gibbs-Duhem Condition and the Relations between Mixing Coefficients of Binary Mixed Electrolytes, 1 195 Gibbs-Duhem equation Glycerol Structural Study of Microemulsions of Glycerol Stabilised by Cetyltrimethylammonium Bromide Dispersed in Heptane + Chloroform Mixtures, 2053 Gold Electrodes Intensely-scattering Phase in Surface-enhanced Raman Scattering by Cyanide on Gold Electrodes, 2 1 1 5 Graphitised Carbon Thermodynamics of Adsorption ofSUBJECT INDEX xi Graphitised Carbon (conl.) 0-n-Dodecylpentaethylene Glycol and 0-n-Dodecyloctaethylene Glycol from Aqueous Solutions on to Graphitised Carbon, 1503 Relaxation Processes on Graphitic Surfaces.Part 1 .-In the Absence and Presence of Adsorbed 4He on Spheron and Grafoil with Increasing Temperature, 1589 Relaxation Processes on Graphitic Surfaces.Part 2.-Adsorption of 4He on Spheron and Grafoil, 161 1 Sn(CH,),, Absorbed on (000 1) Graphite Planes, 2339 Calorimetric Measurement of Heats of Vapour Adsorption on Graphitized Thermal Carbon Black, 1685 Group Additivity Thermodynamic Study of Tetramethyltin, Aqueous Solutions Containing Amino Acids and Peptides. Part 16.-Solute-Soiute Interactions in Solutions containing some N-Acetyl-N-methylamino Acid Amides, 2 19 1 Aqueous Solutions Containing Amino Acids and Peptides. Part 17.-Pairwise Enthalpic Coefficients for the Interaction of N- Acetyl-L-Phenylalaninamide with some N-Acetylamino Acid Amides at 25 "C, 2207 Hamaker constant Photon Correlation Spectroscopy of a Coagulating Suspension of Illite Platelets, 1455 Harned coefficients The Gibbs-Duhem Condition and the Relations between Mixing Coefficients of Binary Mixed Electrolytes, 1195 Heat Capacities Liquid Structure and the Thermal Pressure Coefficients of Cyclohexane + Normal- and Branched-alkane Mixtures, 387 Self-association of Alcohols in Inert Solvents Apparent Heat Capacities and Volumes of Linear Alcohols in Hydrocarbons, 635 and its Interaction with Tripalmitin and L-a-Lecithin, 655 Partial Molar Isobaric Heat Capacities of a Substance in a System containing a Chemical Equilibrium. A Basis for the Estimation of the Effect of Solvent Reorganisation on Heat Capacities of Activation for Chemical Reaction, 1495 Relaxation Processes on Graphitic Surfaces.Part 1 .-In the Absence and Presence of Adsorbed Temperature, 1589 Heat Capacities of Water + Organic-solvent Mixtures, 238 1 Molecular Structure and Orientational Order Effects in Enthalpies and Heat Capacities of Solute Transfer into n-Hexadecane.Part 2.-Cyclic and Aromatic Solutes, 3037 Thermodynamics of Cholesterol Self-association on Spheron and Grafoil with Increasing Helmmholtz Functions Extraction of Standard Helmholtz Functions from Affinity Rate Data, 717 Hexamethylphosphoric Triamide Electrochemical Measmements in the Solvents Hexamethylphosphoric Triamide and Hexamethylthiophosphoric Triamide, 2875 Electrochemical Measurements in the Solvents Hexamethylphosphoric Triamide and Hexamethylthiophosphoric Triamide, 2875 Hexamethylthiophosphoric Triamide Hydration Measurements of Volume Changes on the Formation of Precipitates of Carbonates and Phosphates of Cadmium(I1) and Calcium(I1) in Aqueous Solutions, 2333 H ydrazine Heterogeneous Oxidation of Hydrazine by Barium Chromate, 1 1 13 Hydrogen Infrared Spectroscopic Study of the Adsorption of Hydrogen and Carbon Monoxide on Highly Dehydroxylated Thoria, 21 5 Neutron-sdcattering and Volumetric Study of Hydrogen Adsorbed and Absorbed on Raney Palladium, 1955 Temperature Dependence of the Chemical Potential of Hydrogen in the Two-phase Coexistence Region of the Palladium-Hydrogen System, 292 1 Hydrogen Detection in Ruthenium Oxide Layers by means of the 1H(15N,ay)12C Nuclear Reaction, 2995 Hydrogen Abstraction Non-Arrhenius Behaviour in the Reaction of CF, Radicals with CH,CN and CD,CN, 1303 Hydrogen Bonding Nuclear Quadrupole Resonance Studies of Hydrogen Bonding in Solid Complexes of Chlorobenzoic Acids with Amines, 3 1 1 Self-association of Alcohols in Inert Solvents Apparent Heat Capacities and Volumes of Linear Alcohols in Hydrocarbons, 635 and its Interaction with Tripalmitin and L-a-Lecithin, 655 Calorimetric Investigations on Association in Ternary Systems.Part. 3.-Hydrogen-bonded Complexes in Phenol-Tetrahydrofuran Systems in CCl,, 695 Proton Polarizability of the Hydrogen Bonds in Trifluoroacetic Acid + Pyridine-N-Oxide Systems as a Function of Donor and Acceptor Properties and Environment. Infrared Studies, 1425 Homocomplexation in the corresponding Phenol-Phenolate Systems in Benzonitrile, 202 1 Proton and Li+ Polarizability of Systems with Intramolecular Fluctuation of H+ or Li+ between Four N or NO Acceptors.An Infrared-spectroscopic Investigation of Hydrogen and Li+ Bonds, 2375 2775 Thermodynamics of Cholesterol Self-association Broad Single-minimum Proton Potential and Dissociation of Phenols and Phenolate Salts and Solvation of Esters and Dialkyl Carbonates, Hydrogen Chemisorption Characterization of Sulphided Molybdenum-containing Hydroprocessingxii SIJBJECT INDEX Hydrogen Chemisorption (cont .) Catalysts by Oxygen and Hydrogen Chemisorption, 1655 Carbon in Palladium, 28 13 Hydrogen Sorption by a Supersaturated Solution of Hydrogen Evolution Electron Transfer and Dimerizdtion of Viologen Radicals on Colloidal TiO,, 143 Hydrogen Peroxide Carbon Dioxide-mediated Decomposition of Hydrogen Peroxide in Alkaline Solutions, 1 13 Hydrogenation of Buta- 1,3-diene on Supported Metal Catalysts in Aqueous Solution.Part 1 .--Differences in the Catalytic Action of Al,O,-supported Pt, Pd, Rh and Ru Catalysts, 175 Amorphous Fe81B13.5Si3,5C2. Activity and Segregational Behaviour of the Alloy, 2797 Hydrogenation Hydrogenation of Carbon Monoxide on H ydrogenol ysis Influence of Support Acidity and Ce3+ Additives on the Reactivity of Nickel Particles Highly Dispersed on Various Oxide Supports, 1357 Kinetics of Reaction between Hydroxide Ions and Iron(r1) Complexes in Two Microemulsions. Evidence for Microheterogeneity, 2357 Hydroxide Ions 2-Hydroxy-2-methyl Propanoic Acid Kinetics of the Oxidation of 2-Hydroxy-2-methylpropanoic Acid by Silver(I1) Ions Complexed with 2,2’-Bipyridine in Aqueous Nitrate Media, 10057 Hydroxyl Radicals Rate Constants for the Reactions of Hydroxyl Radicals with Propane and Ethane, 259 Iliite Photon Correlation Spectroscopy of a Coagulating Suspension of Illite Platelets, 1455 Polarized-light Spectroscopic Stirdy of hdocarbocy anines Indocarbocyanine Dyes Solubilized in Amphiphile Aggregates, 1389 Infrared Absorbing Electrons Evidence for Infrared Absorbing Electrons in Alkaline Aqueous Glasses.A Pulse-radiolysis Study at Temperatures down to 6 K, 3067 Proton and Li+ Polarizability of Systems with Infrared Spectroscopy Intramolecular Fluctuation of H+ or Li+ between Four N or NO Acceptors. An Infrared-spectroscopic Investigation of Hydrogen and Li+ Bonds, 2375 Study of Methanol and Water Chemisorbed on Molybdenum Oxide, 19 Infrared Spectroscopic Study of the Adsorption of Hydrogen and Carbon Monoxide on Highly Dehydroxylated Thona, 21 5 Adsorption of Ethane and Ethene OR Tin(iv) Oxide, Tin(1v) Oxide-Silica and Tin(iv) Oxide-Palladium Oxide, 1 3 1 1 Tin Oxide Surfaces.Part 15.--Infrared Study of the Adsorption of Propene on Tin(rv1 Oxide, Tin(iv 1 Tin Oxide Surfaces. Part 14.-Infrared Study of the Oxide-Silica and Tin(rv) Oxide-Palladium Oxide, 1329 Tin Oxide Surfaces. Part 16.-Infrared Study of the Adsorption of Formic Acid, Acrylic Acid and Acrolein on Tin(1v) Oxide, Tin(1v) Oxide-Silica and Tin(1v) Oxide-Palladium Oxide, 1345 Broad Single-minimum Proton Potential and Proton Polarizability of the Hydrogen Bonds in Trifluoroacetic Acid + Pyridine-N-Oxide Systems as a Function of Donor and Acceptor Properties and Environment.Infrared Studies, 1425 Silicon-29 Magic-angle-spinning Nuclear Magnetic Resonance Study of the Crystalline-Amorphous Transition of Zeolite A Containing Trapped Krypton, 143 5 Solvation of Acetone in Protic and Aprotic Solvents and Binary Solvent Mixtures, 1963 Infrared Spectroscopic Studies of the Solvation of Aprotic Solvents and Ions in Methanol, 2131 Infrared Spectroscopic Investigation of Hydroxy-group Siting in H Faujasites, 2257 Infrared Studies of Intermediates in the Oxidation of Propene on ZnO using l80,, 2409 Solvation of Nitroxides, 2421 Solvation of Esters and Dialkyl Carbonates, Carbon Monoxide Chemisorption on a Pt-NaY 2775 Catalyst. Part 2.-Influence of Carbon Monoxide Coverage and of Coadsorbed Molecules on the Infrared Spectrum of Adsorbed Carbon Monoxide (Electron Transfer and Dipole-Dipole Coupling), 2867 Preparation of High-silica Faujasites by Treatment with Silicon Tetrachloride, 2889 Infrared Spectroscopic Study of the Adsorption of CO, CO, and NO on Fluorinated Alumina and Supported Molybdenum-Nickel Catalysts, 1203 Magnesium Oxide, Nickel Oxide and their Solid Solutions, 1283 Spectroscopic Study of NO Adsorption on Luminescence Centres on MgO Surfaces, 29 13 Deammoniation and Dehydroxylation of Calcium Ammonium Chabazites, 3049 Interaction Parameters Interaction Parameters and Miscibility Limits of Poly(dimethylsi1oxane) and Dinonyl Phthalate or Squalane Determined from Studies of the Absorption of Hexane by the Binary Liquid Mixtures, 473 Anionic Poiymerization of a-Methylstyrene in Tetrahydrofuran, 1745 Interaction Parameters and the Equilibrium Intercalation Intercalation of n-Alkylamines by oQirconium Quasi-elastic Neuron-scattering Studies of Phosphate, 545 Intercalated Molecules in Charge-deficient Layer Silicates.Part 2.-High-resolution Measurements of the Diffusion of Water in Montmorillonite and Vermiculite, 833 Tris(2,2’-bipyridine)-Zirconium Phosphates, 2009 Synthesis and Luminisience of Ruthenium... SUBJECT INDEX Xlll Interfaces Spreading Pressires for Fatty-acid Crystals at the Air/Water Interface, 973 Interfacial Tension Minima in Oil +Water + Surfactant Systems. Effects of Salt and Temperature in Systems containing Non-ionic Surfactants, 21 55 Interfacial Tension Minima in Oil +Water + Surfactant Systems.Effects of Salt, Temperature and Alkane in Systems containing Ionic Surfactants, 21 69 Interparticle Interactions Studies of Electrical Double-layer Interactions in Concentrated Silica Sols by Small-angle Neutron Scattering, 1 17 Iodide Ions Kinetics of the Oxidqtion of Substrate Ligands by Transition-metal Cations. The Oxidation of Iodide Ions by Aquacations, 80 1 Iodine Radiation-induced Redox Reactions of Iodine Species in Aqueous Solution. Formation and Characterization of III, I I V , Ivl and IV*I1, the Stability of Hypoiodous Acid and the Chemistry of the Interconversion of Iodide and Iodate, 449 Chemistry of 12*1 in Alkaline Aqueous Solutions of Sodium Iodate Activated by Thermal Neutrons, 2627 Ion Binding Thermodynamics of Ionic Surfactant Binding to Macromolecules in Solution, 885 1011 Exchange Study of Small-port and Large-port Mordenite Modifications.Part 2.--Ion-exchange Properties of Thermally Treated Ammonium Forms, 299 Multicomponent Ion Exchange in Zeolites. Part 1 .-Equilibrium Properties of the Sodium/Calcium/Magnesium-Zeolite A System, 1071 Thermodynamics of Ion-exchange Equilibria in Polyelectrolyte Systems, 1677 Ion Exchange in Zeolites. The Exchange of Cadmium and Calcium in Sodium X Using Different Anionic Backgrounds, 173 1 Multicomponent Ion Exchange in Zeolites. Part 2.-Prediction of Exchange Equilibria over a Range of Solution Concentrations, 3 127 Ion-pair Formation Ultraviolet-Visible Spectrophotometric Determination of Ion-association Constants for Alkylpyridinium Iodides.N-Ethyl-4-cyanopyridinium Iodide in Mixed Solvents Containing Ethanol, 961 Ion-pair Formation as a Determining Factor in the Effectiveness of the Interaction of Electrolytes with Amphiphilic Azo Dyes in Water, 1369 Ultraviolet-Visible Spectrophometric Study of N-Alkylpyridinium Iodides in Non-aqueous Solvents, 2323 Ionic Crystals 703 The Nature of the Surface Charge of Ionic Crystals, Ionic Solvation Ionic Solvation in Water + Cosolvent Mixtures. Part 10.-Free Energies of Transfer of Single Ions from Water into Water+ Ethanonitrile Mixtures, 1985 Ionic Solvation in Water-Cosolvent Mixtures. Part 1 1 .-Free Energies of Transfer of Single Ions from Water into Water-Urea Mixtures, 309 1 Iron Adsorption and Catalytic Properties of Co,Fe, zO, Spinels. Part 1 .-Preparation and Characterisation of Precursors to Ammonia-synthesis Catalysts, 2577 Adsorption and Catalytic Properties of Co,Fe, .20, Spinels.Part '.-Hydrogen Chemisorption on Precursors to Ammonia Synthesis Catalysts, 2593 The Rotating Optical Disc-Ring Electrode. Part 1 .-Collection of a Stable Photoproduct, 2647 Iron Antimonate Phase Cooperation in Oxidation Catalysis. Structural Studies of the Iron Antimonate-Antimony Oxide System, 1693 Visible-light-induced Photodissolution of a-Fe,O, Powder in the Presence of Chloride Anions, 1883 Surface Reduction of some Transition-metal Oxide. An X-ray Photoelectron Spectroscopic Study of Iron, Cobalt, Nickel and Zinc Oxides, 2179 Preparation, Characterization and Photoelectronic Properties of Germanium-substituted Fe,O, Single Crystals, 1263 Iron Oxide Iron Perchlorate Equimolar Mixtures of Trivalent Metal Perchlorates as Constant-ionic-strength Media in Studies of Complex Formation in Dimethyl Sulphoxide.Iron(iii) and Aluminium(iii) Thiocyanate Complex Formation, 1037 Iron(@ Protoporphyrin Reactions of Iron(I1) Protoporphyrin with Strongly Reducing Free Radicals in Aqueous Solutions. A Pulse-radiolytic Study, 233 Isobutene Rotational Degrees of Freedom in the Adsorption of Hydrocarbons on Aerosil, 163 1 Isopropyl Titanate Rutile Growth at the Surface of TiO, Films Deposited by Vapour-phase Decomposition of Isopropyl Titanate, 3 1 17 Isotherms Linear Isotherms in Multicomponent Adsorption onto Silica Gel from Organic Solvents, 185 Isotope Effects Isotopic Effects on the Tracer Diffusion of Water, Methanol and Ethanol Dissolved in Carbon Tetrachloride at 25 "C.103 1 Deuterium Isotope Effect in Concentrated Aqueous Solutions. A Potentiometric and 13C Nuclear Magnetic Resonance Study of Acid Dissociation Constants, 1483 JonesDole equation Separation of Viscosity B Coefficients into Ionic Contributions. Part 4.-Extrapolation Methods Using Tetra-alkylammonium Bromides in Dimethyl Sulphoxide and Hexamethylphosphoric Triamide. 1 133xiv SUBJECT INDEX Kinetic Isotope Effects Kinetic Hydrogen Isotope Effects in the Reaction between 2,4,6-Trinitrotoluene in 1 -Ethylpiperidine in Acetonitrile. The Effect of Pressure, 2959 Kinetic Studies Rate Constants for the Reactions of Hydroxyl Radicals with Propane and Ethane, 259 Kinetics Kinetics of the Reaction between Cyanide Ions and Tris(4-methyl- 1 , 10-phenanthroline)iron(Ii) Cations in Aqueous Solutions. Analysis of Kinetic Data for this Reaction and for Solvolysis of Benzyl Chloride in Water in Terms of Isothermal, Isobaric and Related Isochoric Activation Parameters, 11 Reaction of Catalase with Ethylhydrogen Peroxide, 91 Electron Transfer and Dimerization of Viologen Radicals on Colloidal TiO,, 143 Reactions of Iron(I1) Protoporphyrin with Strongly Reducing Free Radicals in Aqueous Solutions, A Pulse-radiolytic Study, 233 Species in Aqueous Solution.Formation and Characterization of I", Iiv, Ivl and Ivl", the Stability of Hypoiodous Acid and the Chemistry of the Interconversion of Iodide and Iodate, 449 Extraction of Standard Helmholtz Functions from Afhity Rate Data, 717 Thermal Unimolecular Decomposition of /3-Propiolactone (Oxetone-2-one), 1087 Non-Arrhenius Behaviour in the Reaction of CF, Radicals with CH,CN and CD,CN, 1303 Separation of the Effect of Solvent Structure on the Kinetics of Substitution Reactions into Contributions to the Initial and Transition States using Free Energies of Transfer. Kinetics of the Solvolysis of 1,2-Chlorothiocyanatobis( 1,2-diaminoethane)- cobalt(1Ii) Ions in Water and Water + Propan-2-01 Mixtures, 1401 Kinetics of the Gas-phase Thermal Decompositions of 1-Methoxy- I -methylcyclopropane and cis- and trans- 1 -Methoxy-2-methylcyclopropane, 14 15 Kinetic Study of the Gas-phase Decomposition of the Trifluoroacetyl Radical.Effec?s of Temperature and Pressure upon the Rate Constants, 147 1 1761 trans-Dichlorotetrapyridinecobalt(I11) Ion in Water + Dimethyl Sulphoxide Mixtures, 2145 Kinetics of Reaction between Hydroxide Ions and Iron(1r) Complexes in Two Microemulsions.Evidence for Microheterogeneity, 2357 trans-Dichlorobis( 1,2-diaminoethane)cobalt(111) Ion in Water + t-Butyl Alcohol Mixtures, 2475 Experimental and Theoretical Investigation of the Radiation-induced Redox Reactions of Iodine Dehydration of Sodium Carbonate Monohydrate, Kinetics of the Solvolysis of the Kinetics of the Solvolysis of the Kinetics of the Sorption of Water Vapour by Silica Gel, 2681 Heterogeneous Oxidation of Hydrazine by Barium Chromate, 1 1 13 Salt Effects in an Outer-sphere Reaction between Cations, 2967 Influence of Cationic Polyelectrolytes on the Kinetics and Equilibria in Pentacyanoiron(i1) Systems, 3021 Krypton Silicon-29 Magic-angle-spinning Nuclear Magnetic Resonance Study of the Crystalline-Amorphous Transition of Zeolite A Containing Trapped Krypton, 1435 Lanthanum Carboxylates Potentiometric Studies of Some Lanthanum Carboxylates at Constanti Ionic Strength, 983 Chemisorption and Catalysis on LaMO, Oxides, Physicochemical Properties of LaFeO,.Kinetics of Lanthanum Oxides 939 Reduction and of Oxygen Adsorption, 2399 Light Scattering Measurement of Coagulation Rate Constants using Number-fluctuation Spectroscopy, 285 Light-scattering Spectroscopy Solvent-induced Changes in the Visible Transmission Spectrum of Illiois no. 6 Coal. Enhancement of Light Transmission through a Microporous Solid by Solvent-induced Index Matching of the Pores, 991 Taurodeoxycholate Secondary Micelles in 0.8 mol dm-, Sodium Chloride Solution, 2103 Water + AOT+p-Xylene Microemulsions.A Dynamic Light-scattering Study, 1 173 A Study of the Flexibility of Sodium Self-diffusion and Polydispersity in Linear Dichroism Spectroscopy Analysis and Application of Linear Dichroism on Membranes. Description of a Linear-dichroism Spectrometer, 1375 Indocarbocyanine Dyes Solubilized in Amphiphile Aggregates, 1389 Polarized-light Spectroscopic Study of Lipase Activity of Lipase in Water-in-oil Microemulsions, 2667 Liquid Crystals Structural Aspects of Certain Phase Transformations in Lyotropic Liquid-crystal Systems, 273 Indocarbocyanine Dyes Solubilized in Amphiphile Aggregates, 1389 Polarized-light Spectroscopic Study of Liquidus measurements Liquidus Measurements and Coupled Thermodynamic-Phase-diagram Analysis of the NaC1-KC1 System, 1167 Lithium Bonding Proton and Li+ Polarizability of Systems with Intramolecular Fluctuation of H+ or Li+ between Four N or NO Acceptors.An Infrared-spectroscopic Investigation of Hydrogen and Li+ Bonds, 2375SUBJECT INDEX xv L u mi c h r o m e Pulse-radiolysis Study of the Effect of pH on the One-electron Reduction Potentials of Lumichrome Derivatives. 1225 Luminescence Synthesis and Luminiscence of Ruthenium Tris(2,2'-bipyridine~Zirconium Phosphates, 2009 Luminescence Quenching and Flash Photolysis Studies of Acrylamidomethylthionine Copolymers, 2763 Luminescence Centres on MgO Surfaces, 29 13 Thermodynamics of Ionic Surfactant Binding to Macromolecules Macromolecules in Solution, 885 Magnesium Oxide Electron Spin Resonance Spectroscopy of Surface Species formed upon Adsorption of Nitrogen Oxides and Oxygen on High-surface-area NiO-MgO and COO-MgO Solid Solutions, 37 Formation of the m-Dinitrobenzene Radical-anion Dimer in the Triplet Ground State on Magnesium Oxide, 1755 Magnesium Oxide, 2835 Magnesium Oxide, Nickel Oxide and their Solid Solutions, 1283 Oxygen Species Adsorbed on Ultraviolet-irradiated Spectroscopic Study of NO Adsorption on Luminescence Centres on MgO Surfaces, 29 13 Influence of External Fields on Nucleation and Magnetic Fields Crystal Growth.Crystal Growth on n-Octylbiphenyl from Solution in the Presence of Magnetic and Electromagnetic Fields, 673 Mass Spectrometry Electron-impact and Thermodynamic Studies of Potassium Metaborate, 91 3 Meisenheimer Complexes A Kinetic Study of the Formation and Dissociation of the Meisenheimer Complex Formed between 1,3,5-Trinitrobenzene and the Hydroxide Ion in Micellar Dodecyltrimethylammonium Bromide Solution, 335 Membranes Thermodynamics of Transfer of Noble Gases in Hydrophobic Solvents and in Phospholipid Membranes, 579 Analysis and Application of Linear Dichroism on Membranes. Description of a Linear-dichroism Spectrometer, 1375 Metal Oxide Phoyochemical Generation of Singlet Oxygen on Non-transition-metal Oxide Surfaces, 793 Catalysis by Amorphous Metal Alloys.Part Metals 2.-Effects of Oxygen Pretreatment on the Catalytic Activity of Amorphous and Crystallised Ni-P Alloys, 2485 Methanol Study of Methanol and Water Chemisorbed on Molybdenum Oxide, 19 Conversion of Carbon Monoxide into Methanol at Room Temperature and Atmospheric Pressure, 267 Self-diffusion in Monohydric Alcohols under Pressure.Methanol, Methan(2H)ol and Ethanol, 769 Isotopic Effects on the Tracer Diffusion of Water, Methanol and Ethanol Dissolved in Carbon Tetrachloride at 25 "C, 103 1 1-Methox y-1-meth ylcyclopropane Kinetics of the Gas-phase Thermal Decompositions of 1 -Methoxy- 1 -methylcyclopropane and cis- and trans- l-Methoxy-2-methylcyclopropane, 141 5 Kinetics of the Gas-phase Thermal Decompositions of 1 -Methoxy- 1 -methylcyclopropane and cis- and trans- 1 -Methoxy-2-methylcyclopropane, 14 15 Non-Arrhenius Behaviour in the Reaction of CF, 1 -Methoxy-2-methylcyclopropane Methyl cyanide Radicals with CH,CN and CD,CN, 1303 Reactivity of OH and 0- with Aqueous Methyl Viologen Studied by Pulse Radiolysis, 1101 Methyl Viologen Methylamines Adsorption of Methylamines on Dehydrated NaX, NaY and KY Zeolites, 2525 Methylene Blue Effects of Solvent on Stacking Interactions.A Spectrophotometric Study of Thionine Dimerization in H,O and D,O, 255 N-Meth ylformamide Self-diffusion and Volumetric Measurements for N-Methylformamide and N,N-Dimethylformamide at Temperatures from 240 to 3 13 K and Pressures up to 300 MPa, 2821 a-Methylstyrene Interaction Parameters and the Equilibrium Anionic Polymerization of a-Methylstyrene in Tetrahydrofuran, 1745 Micelle Formation Micelles Enthalpies of Mixed-micelle Formation, 207 Investigations of the Dynamic Behaviour of Counterions of Anionic Micellar Systems by Fluorescence Quenching Experiments, 245 A Kinetic Study of the Formation and Dissociation of the Meisenheimer Complex Formed between 1,3,5-Trinitrobenzene and the Hydroxide Ion in Micellar Dodecyltrimethylammonium Bromide Solution, 335 Photoionization of N,N,N',N'-Tetramethylbenzidine in Dodecyltrimethylammonium Chloride Cationic Micelles under 337 nm Laster Irradiation, 1025 Indocarbocyanine Dyes Solubilized in Amphiphile Aggregates, 1389 N,N,N',N'-Tetramethylbenzidine and its Protonated Forms in Sodium Dodecyl Sulphate Anionic Micelles under 337 nm Laser Irradiation, 1669 Taurodeoxycholate Secondary Micelles in 0.8 mol dmP3 Sodium Chloride Solution, 2103 Oil + Water + Surfactant Systems.Effects of Salt, Polarized-light Spectroscopic Study of Photochemical Behaviour of A Study of the Flexibility of Sodium Interfacial Tension Minima inxvi SUBJECT INDEX Micelles (cont.) Temperature and Alkane in Systems containing Ionic Surfactants, 2169 Effects of Pressure on Reversed Micellar Systems. Rates of the Keto-Enol Transformation of Pen tane-2,4-dione, 228 7 the Homologous Series of cx-Dodecyl-o-h ydroxypol y( oxyeth ylene) Surfactants, C,,EOj ( j = 4, 5 , 6, 8 and 12), and of C,,EO,, 2693 Binding of 2-Naphtholate Ions to a Water-in-oil Cetyltrimethylammonium Bromide Microemulsion. The Enthalpy and Entropy of Interaction, 2723 Determination of the Rate of Tautomerization of 1 -Phenylbutane- 1,3-dione (Benzoylacetone) using the Technique of Solubilization into Micelles, 2941 Lower Consolute Boundaries of a Poly(oxyeth1ene) Surfactant in Aqueous Solutions of Monovalent Salts, 2947 Photphysics of the Excited Uranyl Ion in Aqueous Solutions.Part 5.-Fluorescence Quenching by Micellar Solutions of Triton X-100, 1891 Apparent Molar Volumes for Aqueous Solutions of Microemulsions Binding of 2-Naphtholate Ions to a Water-in-oil Cetyltrimethylammonium Bromide Microemulsion. The Enthalpy and Entropy of Interaction, 2723 Structural Study of Microemulsions of Glycerol Stabilised by Cetyltrimethylammonium Bromide Dispersed in Heptane + Chloroform Mixtures, 2053 Kinetics of Reaction between Hydroxide Ions and Iron(I1) Complexes in Two Microemulsions. Evidence for Microheterogeneity, 2357 2667 Water + AOT +p-Xylene Microemulsions.A Dynamic Light-scattering Study, 1 173 Activity of Lipase in Water-in-oil Microemulsions, Self-diffusion and Polydispersity in Miscibility Interaction Parameters and Miscibility Limits of Poly(dimethylsi1oxane) and Dinonyl Phthalate or Squalane Determined from Studies of the Absorption of Hexane by the Binary Liquid Mixtures, 473 Mixed Micelles Mixing Coefficients Enthalpies of Mixed-micelle Formation, 207 The Gibbs-Duhem Condition and the Relations between Mixing Coefficients of Binary Mixed Electrolytes, 1195 Molar Volume Nuclear Magnetic Resonance and Molar-volume Studies of the Complex Formed between Aluminium(II1) and the Sulphate Anion, 193 Molecular-orbital Calculations Ab Znitio Molecular-orbital Study on the Adsorption of Ethylene and Oxygen Molecules over Vanadium Oxide Clusters, 15 13 Molten-salt Hydrates Molten-salt Hydrate Media.Cobalt(r1) Ions in ZnC1, + H,O and CaCl, + H,O Systems, 265 Molten Salts X-Ray-diffraction Analysis of the Molten ZnC1,-KCl System, 190 1 Molybdenum-containing Catalysts characterization of Sulphided Moly bdenum-containing Hydroprocessing Catalysts by Oxygen and Hydrogen Chemisorption, 1655 Electron Spin Resonance and Electron Spin-echo Spectroscopic Studies of Supported-molybdenum Catalysts. Interaction between Molybdenum, Adsorbate and Oxygen Molecules, 2083 Molybdena/Silica System Photoreduced in a Carbon Monoxide Atmosphere, 2307 Spectroscopic Characterization of a Molybdenum Oxide Study of Methanol and Water Chemisorbed on Molybdenum Oxide, 19 Molybdenum-Nickel Catalysts Infrared Spectroscopic Study of the Adsorption of CO, CO, and NO on Fluorinated Alumina and Supported Molybdenum-Nickel Catalysts, 1203 Monte Carlo Methods Physical Adsorption of Gases on Heterogeneous Surfiices.Model Study of the Effects of Simultaneous Vertical and Lateral Interactions by Monte Carlo Methods, 355 Mordenite Study of Small-port and Large-port Mordeni te Modifications. Part '.--Ion-exchange Properties of Thermally Treated Ammonium Forms, 299 A Shape-selective Platinum-loaded Mordenite Catalyst for the Hydrocracking of Paraffins by the Chemical Vapour Deposition of Silicon Alkoxide, 2757 Fluorine. I 16 1 Mossbauer Spectroscopy Catalytic Properties of H Mordenite Modified with An Zn Situ Mossbauer Investigation of the Influence of Metal-Support and Metal-Metal Interactions on the Activity and Selectivity of Iron- Ruthenium Catalysts, 2293 Muonium Spin Rotation Studies of Muonium-substituted Molecules in Propan-2-one and in Aqueous Solutions of Propan-2-one, 433 n-Hexadecane Molecular Structure and Orientational Order Effects in Enthalpies and Heat Capacities of Solute Transfer into n-Hexadecane.Part 2.-Cyclic and Aromatic Solutes, 3037 Neopentane Isomerization of Alkanes on Epitaxially Oriented (1 1 1) Pd-Cu and Pd-Ag Alloy Films, 1447 Neutron-diffraction Spectroscopy Phase Cooperation in Oxidation Catalysis. Structural Studies of the Iron Antimonate-Antimony Oxide System, 1693 Neutron-scattering Studies Quasi-elastic Neuron-scattering Studies of Intercalated Molecules in Charge-deficient Layer Silicates.Part 2.-High-resolution Measurements of the Diffusion of Water in Montmorillonite and Vermiculite, 833SUBJECT INDEX xvii Neutron-scattering Studies (cont.) Neutron-scattering and Volumetric Study of Hydrogen Adsorbed and Absorbed on Raney Palladium, 1955 Molecular Diffusion in Monolayer Films of Water Adsorbed on a Silica Surface, 2067 Small-angle Neutron-scattering Studies of Silica Sols in Water at High Temperatures, 2845 Neutron-scattering Techniques Activity of Lipase in Water-in-oil Microemulsions, 2667 Nickel Influence of Support Acidity and Ce3+ Additives on the Reactivity of Nickel Particles Highly Dispersed on Various Oxide Supports, I357 Studies of the EfTect of Calcination on the Dispersion and Reduction of Nickel Supported on Alumina by X-Ray Photoelectron Spectroscopy, X-Ray Diffraction.Chemisorption and Catalytic Activity, 2733 Nickel Lauryl Sulphate Investigations of the Dynamic Behaviour of Counterions of Anionic Micellar Systems by Fluorescence Quenching Experiments, 245 Nickel Oxide Electron Spin Resonance Spectroscopy of Surface Species formed upon Adsorption of Nitrogen Oxides and Oxygen on High-surface-area NiO-MgO and COO-MgO Solid Solutions. 37 Surface Reduction of some Transition-metal Oxide. An X-ray Photoelectron Spectroscopic Study of Iron, Cobalt, Nickel and Zinc Oxides, 21 79 Magnesium Oxide, Nickel Oxide and their Solid Solutions, I283 Spectroscopic Study of NO Adsorption on Nitric Acid Nuclear Magnetic Resonance Investigation of Solutions of Nitric Acid and Perchloric Acid in Water + Dimethyl Sulphoxide Mixed Solvents, 2365 Nitroalkanes Radiolytic Preparation of Radical Cations of Nitroalkanes and Related Compounds, 565 Nitrogen Oxides Decomposition of N,O on Fe2O3/AI2O3 Catalysts.Relationship between Physicochemical and Catalytic Properties, 2043 Spectroscopy of Alkaline-earth-metal Oxides. Part '.-Dependences upon Temperature of Pre-activation for SrO, 2027 Magnesium Oxide, Nickel Oxide and their Solid Solutions, 1283 Crystal Planes, 298 1 Comparison of the Surface Reactivity and Spectroscopic Study of NO Adsorption on Decomposition of Nitrous Oxide on Palladium C-Nitroso Compounds Electron Spin Resonance Studies of the Radicals formed from C-Nitroso Compounds and Olefins. Part 4.-Reactions of Alicyclic Olefins with C-Nitroso Compounds, 12 15 Nitroxides Solvation of Nitroxides, 2421 N,N-Dimeth ylacetamide Dielectric Relaxation in Mixtures of N,N-Dimethylacetamide with some Aliphatic Alcohols, 397 Noble Gases Thermodynamics of Transfer of Noble Gases in Hydrophobic Solvents and in Phospholipid Membranes, 579 Noble Metals X-Ray Scattering Structural Investigation of Pt and Pt-Sn Catalysts Supported on Nylon, 321 Nuclear Magnetic Resonance Solvation of Acetone in Protic and Aprotic Solvents High-resolution Solid-state Nuclear Magnetic and Binary Solvent Mixtures, 1963 Resonance Studies of Dealuminated Zeolite Y , 3003 Nuclear Magnetic Resonance Spectroscopy "0 Nuclear Magnetic Resonance Study of the Rotational Motion of the Sulphate Ion in Aqueous Solution, 127 Nuclear Magnetic Resonance and Molar-volume Studies of the Complex Formed between Aluminium(III) and the Sulphate Anion, 193 Nuclear Magnetic Resonance and Dielectric Relaxation Investigations of Water Sorbed by Spherisorb Silica, 847 Silicon-29 Magic-angle-spinning Nuclear Magnetic Resonance Study of the Crystalline-Amorphous Transition of Zeolite A Containing Trapped Krypton, 1435 Deuterium Isotope Effect in Concentrated Aqueous Solutions.A Potentiometric and 13C Nuclear Magnetic Resonance Study of Acid Dissociation Constants, 1483 Sodium Cryptate Formed by 4,7,13, I8-Tetraoxa- 1,lO- diazabicyclo[8.5.5]eicosane (C211) in Various Solvents, 1623 Aluminium-27 Nuclear Magnetic Resonance Studies of the Hydrolysis of Aluminium(II1). Part 7.-Spectroscopic Evidence for the Cation [A 10H]2 from Line-broadening Studies at High Dilution, 1923 Solutions of Nitric Acid and Perchloric Acid in Water + Dimethyl Sulphoxide Mixed Solvents, 2365 Microdynamics of Methane, Ethane and Propane in ZSM-5 Type Zeolites, 2541 Solvation of Esters and Dialkyl Carbonates. 2775 Carbon Monoxide Chemisorption on a Pt-NaY A Nuclear Magnetic Resonance Study of the Nuclear Magnetic Resonance Investigation of Catalyst.Part 1 .-Determination of the Distribution of the Chemisorbed Carbon Monoxide Phase by a 12gXe-Nuclear Magnetic Resonance Study of Adsorbed Xenon, 2855 The Inclusion of Haloperidol and Trifluperidol by cx- and y-Cyclodextrins A I9F Nuclear Magnetic Resonance Study, 1247 Nuclear Quadruple Resonance Spectroscopy 35Cl Nuclear Quadrupole Resonance Studies of Hydrogen Bonding in Solid Complexes of Chlorobenzoic Acids with Amines, 3 1 1xviii SUBJECT INDEX Nuclear Reaction Hydrogen Detection in Ruthenium Oxide Layers by means of the 1H(1BN,ay)12C Nuclear Reaction, 2995 Nucleation Influence of External Fields on Nucleation and Crystal Growth.Crystal Growth on n-Octylbiphenyl from Solution in the Presence of Magnetic and Electromagnetic Fields, 673 The Thermal Decomposition in the Solid Phase (Crystolysis) of Silver Malonate, 2503 Study of Dispersed Solid-phase Ontogenesis using Hierarchical Structure Data, 1275 Number-fluctuation Spectroscopy Measurement of Coagulation Rate Constants using Number-fluctuation Spectroscopy, 285 Olson-Simonson Effect Cations, 2967 Salt Effects in an Outer-sphere Reaction between Ontogenesis Study of Dispersed Solid-phase Ontogenesis using Hierarchical Structure Data, 1275 Organic Solvents Comments on Gill’s Approach to the Evaluation of Single Limiting Ionic Conductances in Organic Solvents, 241 Oscillatory Phenomena A Thermokinetic Foundation for Oscillatory Phenomena in Gaseous Organic Oxidations under Well Stirred Flowing Conditions, 343 Belousov-Zhabotinsky System.Experimental Behaviour Studied by Potentiometric Techniques, Kinetic Steps and an Explanation of the Oscillations by the D’ Alba-Di Lorenzo Model, 42 1 Reaction Systems, 75 1 Isothermal, Open Systems. Cubic Autocatalysis and the Influence of Competitive Reactions, 1563 Oscillatory Phenomena in the Trigger Waves in Iodate-driven Oscillatory Multistability and Sustained Oscillations in Osmotic Coefficients Aqueous Solutions Containing Amino Acids and Peptides.Part 1 6.-Solute-Solute Interactions in Solutions containing some N-Acetyl-N’-methylamino Acid Amides, 219 1 Interactions between Metal-complex Ions and Water. Part 2.-Osmotic and Mean Activity Coefficients of Trivalent Metal Complex Chlorides in Aqueous Solutions at their Freezing Points, 2805 Cryoscopic, Infrared Spectroscopic and Dielectric Studies of Associated Cyclohexanol + Benzene Mixtures. 1141 Oxetan-2-one Thermal Unimolecular Decomposition of p-Propiolactone (Oxetone-2-one), 1087 Oxidation Kinetics of the Oxidqtion of Substrate Ligands by Transition-metal Cations. The Oxidation of Iodide Ions by Aquacations, 801 Identification of Active Oxide Ions in a Bismuth Molybdate Selective Oxidation Catalyst, 2903 Heterogeneous Oxidation of Hydrazine by Barium Chromate, 1 1 13 Oxychlarination Catalysis Adsorption and Conductivity Studies in Oxychlorination Catalysis.Part 4.-Effect of Adsorption on the Conductivity of Copper(1) Chloride Films, 69 Oxychlorination Catalysis. Part 5.-Temperature-programmed Desorption, 83 Physicochemical Properties of LaFeO,. Kinetics of Adsorption and Conductivity Studies in Oxygen Adsorption Reduction and of Oxygen Adsorption, 2399 Oxygen Chemisorption Characterization of Sulphided Molybdenum-containing Hydroprocessing Catalysts by Oxygen and Hydrogen Chemisorption, 1655 Magnesium Oxide, 2835 Oxygen Species Adsorbed on Ultraviolet-irradiated Pair-interaction Coefficients Enthalpic McMillan-Mayer Coefficients from Literature Data on Excess Enthalpies.Application to Solutions of Alkanes in Alkan-1-ols, 1015 Calorimetric Investigation of NaI-Alcohol Interactions in Alcohol +Alcohol Mixtures, 191 3 Electrochemical Reduction of Bicarbonate Ions at a Bright Palladium Cathode, 7 13 Isomerization of Alkanes on Epitaxially Oriented (1 1 1 ) Pd-Cu and Pd-Ag Alloy Films, 1447 Neutron-sdcattering and Volumetric Study of Hydrogen Adsorbed and Absorbed on Raney Palladium, 1955 Carbon in Palladium, 28 13 of Hydrogen in the Two-phase Coexistence Region of the Palladium-Hydrogen System, 292 1 Decomposition of Nitrous Oxide on Palladium Crystal Planes, 298 1 Palladium Hydrogen Sorption by a Supersaturated Solution of Temperature Dependence of the Chemical Potential Palladium Oxide Tin Oxide Surfxes.Part 14.---Infrared Study of the -4dsorption of Ethane and Ethene on Tin(iv) Oxide, Tin(iv) Oxide-Silica and Tin(1v) Oxide-Palladium Oxide, 131 1 Tin Oxide Surfaces. Part 15.--Infrared Study of the Adsorption of Propene on Tin(iv) Oxide, Tin(1v) Oxide-Silica and Tin(1v) Oxide-Palladium Oxide, 1329 Tin Oxide Surfaces. Part 16.-Infrared Study of the Adsorption of Formic Acid, Acrylic Acid and Acrolein on Tin(1v) Oxide, Tin(1v) Oxide-Silica and Tin(1v) Oxide-Palladium Oxide, 1345 Partition Coefficients Effects of Surface Heterogeneity on Liquid Adsorption Chromatography with Mixed Mobile Phases, 553 Pentacyanoiron( 11) Influence of Cationic Polyelectrolytes on the Kinetics and Equilibria in Pentacyanoiron(i1) Systems, 302 1 Pentahalogeno Phenols Calorimetric Investigations on Association in Ternary Systems.Part. 3.-Hydrogen-bondedSUBJECT INDEX xix Pentahalogeno Phenols (cont.) Complexes in Phenol-Tetrahydrofuran Systems in CCl,, 695 Perchloric Acid Nuclear Magnetic Resonance Investigation of Solutions of Nitric Acid and Perchloric Acid in Water + Dimethyl Sulphoxide Mixed Solvents, 2365 Pervoskite Layer Structures General Trends in Phase Transitions in an Homologous Series. Polymorphism in (n-C,H,,NH,),MnCI, as Determined by Adiabatic Calorimetry from 18 to 313 K, 3059 Electrical Properties of the Perylene-p-Chloranil Complex and the EfYect of o-Chloranil as an Impurity, 537 Per ylene Phase Diagrams Liquidus Measurements and Coupled Thermodynamic-Phase-diagram Analysis of the NaCI-KCl System, 1167 Phase Transformations Structural Aspects of Certain Phase Transformations in Lyotropic Liquid-crystal Systems, 273 General Trends in Phase Transitions in an Homologous Series.Polymorphism in (n-C,H,,NH,),MnCI, as Determined by Adiabatic Calorimetry from 18 to 3 13 K, 3059 Phase Transitions Solid-Solid Phase Transitions in K,Cr,O, at Pressures below 0.4 GPa from Differential Thermal Analysis under Hydrostatic Pressure, 1789 Phenols Dissociation of Phenols and Phenolate Salts and Homocomplexation in the corresponding Phenol-Phenolate Systems in Benzonitrile, 202 1 2-Phen ylbenzoxazole Investigations of the Dynamic Behaviour of Counterions of Anionic Micellar Systems by Fluorescence Quenching Experiments, 245 Phosphine Oxides Sorption-Diffusion in Heterogeneous Systems.Part 9.'. - Kinetic and Thermodynamic Effects Determining the Enantio-differentiating Chirospecificity of Solid-bound Chiral Phosphine Oxides, 2273 Photocatalysis Correlation of the Crystal Structure of Titanium Dioxide Prepared from Titanium Tetra-2-propoxide with the Photocatalytic Activity for Redox Reactions in Aqueous Propan-2-01 and Silver Salt Solutions, 61 Photocatalytic Dehydrogenation of Aliphatic Alcohols by Aqueous Suspensions of Platinized Titanium Dioxide, 246'7 Titanium Dioxide, 1237 Photolysis of Water over Metallized Powdered Photochemistry Measurement of the Activity of Hydrogen and Oxygen Catalysts by a Photochemical Relaxation Method, 601 Cellulose. Part 4.-Diffusion-controIled Photochemistry of Compounds Adsorbed into Mechanism of Ru(bpy)i+ Luminscence Quenching by Copper(II), 735 Non-transition-metal Oxide Surfaces, '793 N,N,N',N'-Tetramethylbenzidine in Dodecyltrimethylammonium Chloride Cationic Micelles under 337 nni Laster Irradiation, 1025 N, N,N',N'-Tetramethylbenzidine and its Protonated Forms in Sodium Dodecyl Sulphate Anionic Micelles under 337 nm Laser Irradiation, 1669 Powder in the Presence of Chloride Anions, 1883 Phoyochemical Generation of Singlet Oxygen on Photoionization of Photochemical Behaviour of Visible-light-induced Photodissolution of a-Fe,O, Pho toelec trochemistr y Photoelectrochemistry in Colloidal Systems.Part 2.-A Photogalvanic Cell Based on TiO, Semiconductor Colloid, 509 The Rotating Optical Disc-Ring Electrode. Part 1 .-Collection of a Stable Photoproduct, 264'7 Preparation, Characterization and Photoelectronic Properties of Germanium-substituted Fe,O, Single Crystals, 1263 Photographic Film Kinetic Models for the Development of Density in Photographic and Radiographic Film, I647 Non-Arrhenius Behaviour in the Reaction of CF, Radicals with CH,CN and CD,CN, 1303 Photolysis of Water over Metallized Powdered Titanium Dioxide: 1237 Photo1 ysis Photon correlation spectroscopy Photon Correlation Spectroscopy of a Coagulating Activity of Lipase in Water-in-oil Microemulsions, Suspension of Illite Platelets, 1455 2667 Photophysics Photophysics of the Excited Uranyl Ion in Aqueous Solutions.Part 4.-Quenching by Metal Ions, 49 Photphysics of the Excited Uranyl Ion in Aqueous Solutions. Part 5.-Fluorescence Quenching by Micellar Solutions of Triton X- 100, 189 1 Photoredox Reactions Spectroscopic Characterization of a Molybdena/Silica System Photoreduced in a Carbon Monoxide Atmosphere, 2307 Time-resolved Photoredox Reactions of Colloidal CdS, 1999 Photo-oxidation of Water using Prussian Blue as Catalyst, 2461 Physical Adsorption Physical Adsorption of Gases on Heterogeneous Surfaces.Model Study of the Effects of Simultaneous Vertical and Lateral Interactions by Monte Carlo Methods, 355 Platinum Effect of Oxide Thickness on the Rates of some Exchange Reactions of Hydrocarbons on Redox Reactions on a Platinum Electrode, 403 Silica-supported Rh-Pt Bimetallic Catalysts, 1871 Aspects of Temperature-programmed Analysis of some Gas-Solid Reactions. Part 1 .-Dispersion Effects in Temperature-programmed Bulkxx SUBJECT INDEX Platinum (cont.) Reduction and Temperature-programmed Desorption, 2605 Polarimetry Sorption-Diffusion in Heterogeneous Systems.Part 9.’. * - Kinetic and Thermodynamic Effects Determining the Enantio-differentiating Chirospecificity of Solid-bound Chiral Phosphine Oxides, 2273 Polarographic Cells Some Relationships Involved in the Variation of Electrochemical Gas-sensor Currents with Gas-sample Flow Rates, 1863 Polarograph y Electrochemical Measurements in the Solvents Hexamethylphosphoric Triamide and Hexamethylthiophosphoric Triamide, 2875 Interaction Parameters and Miscibility Limits of Poly(dimetbylsi1oxane) Poly(dimethylsi1oxane) and Dinonyl Phthalate or Squalane Determined from Studies of the Absorption of Hexane by the Binary Liquid Mixtures, 473 Lower Consolute Boundaries of a Poly(oxyeth1ene) Surfactant in Aqueous Solutions of Monovalent Salts, 2947 Pol yacetylene p-Doping of (CH), to the Metallic Regime with Gaseous Oxygen. Application to Oxygen Fuel-cell-type Electrodes, 105 Self-diffusion and Polydispersity in Pol ydispersit y Water + AOT+p-Xylene Microemulsions.A Dynamic Light-scattering Study, 11 73 Polyelectrolytes Thermodynamics of Ion-exchange Equilibria in Influence of Cationic Polyelectrolytes on the Polyelectrolyte Systems, 1677 Kinetics and Equilibria in Pentacyanoiron(rr) Systems, 302 1 Polymerization Interaction Parameters and the Equilibrium Anionic Polymerization of a-Methylstyrene in Tetrahydrofuran, 1745 Pore Structure Effect of Pore Structure and Macroscopic Non-homogeneity on the Relative Gas Permeability of Porous Solids, 1 183 Relative to Capillary Condensation, 293 1 Pore Network Interactions in Ascending Processes Porous Plugs Effect of Pore Structure and Macroscopic Non-homogeneity on the Relative Gas Permeability of Porous Solids, 1 183 Concentration Dependence of Electrokinetic Transport Coefficients of Non-aqueous Binary Mixtures through Weakly Charged Porous Plugs, 609 Porphyrins Binding and Decomposition of Oxovanadium(1v) Phthalocyanine, Tetraphenylporphyrin and Etioprophyrin on Hydrotreating Catalysts Studied by X-Ray Photoelectron and Ultraviolet-Visible Spectroscopies.Relevance to Catalytic Demetallisation, 1047 Redox Properties of Copper Tetra(4-N,N’,N”-trimethylanilinium)porphyrin. Electrochemical and Spectral Studies, 1577 Potassium Chloride Liquidus Measurements and Coupled Thermodynamic-Phase-diagram Analysis of the NaCl-KCl System.1 167 Potassium Chromate Solid-Solid Phase Transitions in K,Cr,O, at Pressures below 0.4 GPa from Differential Thermal Analysis under Hydrostatic Pressure, 1789 Potassium Metaborate Electron-impact and Thermodynamic Studies of Potassium Metaborate, 9 13 Potential-energy Surface Solvent Relaxation and Proton Transfer in the Pressure Dependence of Activation and Reaction (H502)+ (H,O), Species, 1547 Volumes, 875 Potentiometry Potentiometric Studies of Some Lanthanum Carboxylates at Constanti Ionic Strength, 983 Deuterium Isotope Effect in Concentrated Aqueous Solutions. A Potentiometric and 13C Nuclear Magnetic Resonance Study of Acid Dissociation Constants, 1483 Homocomplexation in the corresponding Phenol-Phenolate Systems in Benzonitrile, 2021 Solute-Solvent Interactions in Water-t-Butyl Alcohol Mixtures.Part 14.-AGe, AH* and A@ of Transfer for Alkaline-earth-metal Cations, 308 1 Dissociation of Phenols and Phenolate Salts and Pressure Effects The Pressure Effect on Strained Transition States. Correlation between Strain and Volume of Activation : Mechanistic and Synthetic Involvements, 2437 Propan-2-01 Separation of the Effect of Solvent Structure on the Kinetics of Substitution Reactions into Contributions to the Initial and Transition States using Free Energies of Transfer. Kinetics of the Solvolysis of 1,2-Chlorothiocyanatobis( 1,2-diarninoethane)- cobalt(II1) Ions in Water and Water + Propan-2-01 Mixtures, 1401 Alcohol Decomposition on Zinc Oxide.Propan-2-01, 3073 Temperature-programmed Desorption Studies of Propan-2-0ne Studies of Muonium-substituted Molecules in Propan-2-one and in Aqueous Solutions of Propan-2-one, 433 Propane Rate Constants for the Reactions of Hydroxyl Radicals with Propane and Ethane, 259 Propene Tin Oxide Surfaces. Part 15.--Infrared Study of the Adsorption of Propene on Tin(iv) Oxide, Tin(1v) Oxide-Silica and Tin(rv) Oxide-Palladium Oxide, 1329 Activity of Supported Tungsten Oxide Catalysts for the Metathesis of Propene, 1705SUBJECT INDEX xxi Propene (cont.) Infrared Studies of Intermediates in the Oxidation of Propene on ZnO using l80,, 2409 Proteins Effects of Pressure on Charge Transport in Protein Powders, 1939 Proton Transfer 35CC1 Nuclear Quadrupole Resonance Studies of Hydrogen Bonding in Solid Complexes of Chlorobenzoic Acids with Amines, 3 1 1 Substituent Effects on Proton Tunnelling.Reaction between 2,4,6-Trinitrotoluene and 1 -Substituted Piperidines in Acetonitrile, 1441 (H,O,)+ (H,O), Species, 1547 Solutions of Nitric Acid and Perchloric Acid in Water + Dimethyl Sulphoxide Mixed Solvents, 2365 The Pressure Effect on Strained Transition States. Correlation between Strain and Volume of Activation : Mechanistic and Synthetic Involvements, 2437 Solvent Relaxation and Proton Transfer in the Nuclear Magnetic Resonance Investigation of Prussian Biue Photo-oxidation of Water using Prussian Blue as Catalyst, 2461 Pulse Radiolysis Reactions of Iron(1I) Protoporphyrin with Strongly Reducing Free Radicals in Aqueous Solutions.A Pulse-radiolytic Study, 233 Reactivity of OH and 0- with Aqueous Methyl Viologen Studied by Pulse Radiolysis, 1101 Photo-oxidation of Water using Prussian Blue as Catalyst, 2461 Pulse-radiolysis Study of the Effect of pH on the One-electron Reduction Potentials of Lurnichrome Derivatives, 1225 Evidence for Infrared Absorbing Electrons in Alkaline Aqueous Glasses. A Pulse-radiolysis Study at Temperatures down to 6 K, 3067 Pyridine in Acetic Acid Kine!ic investigation of the Oxidation of Bromide 1011s by Cobalt(II1). Part 1.--The Influence of Pyridine in Acetic Acid Solvent, 2095 Pyridine-N-oxides Broad Single-minimum Proton Potential and Proton Polarizability of the Hydrogen Bonds in Trifluoroacetic Acid + Pyridine-N-Oxide Systems as a Function of Donor and Acceptor Properties and Environment. Infrared Studies, 1425 Quenching Photophysics of the Excited UranyI Ion in Aqueous Solutions.Part 4.-Quenching by Metal Ions, 49 Radical Cations Radiolytic Preparation of Radical Cations of Nilroalkanes and Related Compounds, 565 Electron Spin Resonance Studies of the Radicals Formed from C-Nitroso Compounds and Olefins. Part. 3.-Reactions of Fluoro-olefins with Trifluoronitrosomethane and with 3,4,6-Tribromonitrosobenzene, 679 Radical Formation Electron Spin Resonance Studies of the Radicals formed from C-Nitroso Compounds and Olefins. Part 4.-Reactions of Alicyclic Olefins with C-Nitroso Compounds, 12 15 Radical Reactions Reactions of Sulphate, Phosphate and Hydroxyi Radicals with Furan. An Electron Spin Resonance Investigation in Solution, 1979 Reactions of Cobalt(iI1) Compounds with some Free Radicals Derived from Uracil, 2569 Radical Recombination Kinetic Electron Spin Resonance Investigation of the Monohydronitro Free Radical of 2,3,5,6-Tetrachloronitrobenzene, 1467 Radiographic Film Kinetic Models for the Development of Density in Photographic and Radiographic Film, 1647 Radiation-induced Redox Reactions of Iodine Radio1 ysis Species in Aqueous Solution.Formation and Characterization of I", II", Ivr and IVr1', the Stability of Hypoiodous Acid and the Chemistry of the Interconversion of Iodide and Iodate, 449 Radiolysis. An Electron Spin Resonance Study, 727 Alkyl-radical-Chloride-ion Adducts Formed in the Radiolysis of Chloroalkanes.An Electron Spin Resonance Study, 1095 Solvation of Nitroxides, 2421 Correlation of the Crystal Structure of Titanium Dioxide Prepared from Titanium Tetra-2-propoxide with the Photocatalytic Activity for Redox Reactions in Aqueous Propan-2-a1 and Silver Salt Solutions, 61 Radiation-induced Redox Reactions of Iodine Species in Aqueous Solution. Formation and Characterization of I I I , Irv, Ivl and Ivrrl, the Stability of Hypoiodous Acid and the Chemistry of the Interconversion of Iodide and Iodate, 449 Tetra(4-N,N',N"-trimethylanilinium)porphyrin. Electrochemical and Spectral Studies, 1577 Redox Properties of Various Bismuth Molybdate Phases in the Catalytic Oxidation of But-1-ene, 2107 Structures of Diazabenzene Cations formed by Raman Spectroscopy Redox Reactions Redox Properties of Copper Relaxation Functions Aqueous Solutions.Part 3.-Thermal and Acoustic Characteristics of Water, 5 19 Relaxation Processes Relaxation Processes on Graphitic Surfaces. Part 1 .-In the Absence and Presence of Adsorbed ,He on Spheron and Grafoil with Increasing Temperature, 1589 Relaxation Processes on Graphitic Surfaces. Part 2.-Adsorption of ,He on Spheron and Grafoil, 161 1 Relaxation Studies Ultrasonic Attenuation in Aqueous Solutions of CI-, /3- and y-Cyclodextrins, 2551 Rhodium Electrochemical and Surface X-ray Photoelectron Spectroscopy Study on the Rhodium-Carbonate Electrode in Molten Nitrates, 621xxii SUBJECT INDEX Rhodium (cont.) Exchange Reactions of Hydrocarbons on Silica-supported Rh-Pt Bimetallic Catalysts, 187 1 Interaction of Carbon Monoxide with Rhodium Catalysts.Studies of Adsorption and Termal Desorption, 2225 Rotational Motion 170 Nuclear Magnetic Resonance Study of the Rotational Motion of the Sulphate Ion in Aqueous Solution, 127 Ruthenium Formation and Stability of Ru"' Incorporated in Synthesis and Luminiscence of Ruthenium TiO, (Rutile), 8 13 Tris(2,2'-bipyridine)-Zirconium Phosphates, 2009 Hydrogen Detection in Ruthenium Oxide Layers by means of the lH(15N,ay)12C Nuclear Reaction, 2995 Rutherford Backscattering Spectrometry Hydrogen Detection in Ruthenium Oxide Layers by means of the lH(l5N,ay)l2C Nuclear Reaction, 2995 Rutile Rutile Growth at the Surface of TiO, Films Deposited by Vapour-phase Decomposition of Isopropyl Titanate, 3 1 17 Salt Effects Lower Consolute Boundaries of a Poly(oxyeth1ene) Surfactant in Aqueous Solutions of Monovalent Salts, 2947 Cations, 2967 Scaled-particle Theory Salt Effects in an Outer-sphere Reaction between A Thermodynamic Study of the Preferential Interaction of the Polyoxometallate Electrolyte Na,SiW,,O,; 14H,O with Ethers in Aqueous Solution, 25 13 Scanning Electron Microscopy Dehydration of Sodium Carbonate Monohydrate, X-Ray Photoelectron-spectroscopic Studies of 1761 Carbon-fibre Surfaces.Part 5.-The Effect of pH on Surface Oxidation, 2745 Amorphous Fe81B,3,5Si3,5Cz. Activity and Segregational Behaviour of the Alloy, 2797 Self-association of Alcohols in Inert Solvents Hydrogenation of Carbon Monoxide on Self-association Apparent Heat Capacities and Volumes of Linear Alcohols in Hydrocarbons, 635 and its Interaction with Tripalmitin and L-a-Lecithin, 655 Thermodynamics of Cholesterol Self-association Self-diffusion Self-diffusion in Monohydric Alcohols under Pressure.Methanol, Methan(*H)ol and Ethanol, 769 Microdynamics of Methane, Ethane and Propane in ZSM-5 Type Zealites, 2541 Self-diffusion and Volumetric Measurements for N-Methylformamide and N,N-Dimethylformamide at Temperatures from 240 to 3 13 K and Pressures up to 300 MPa, 282 1 Self-diffusion and Polydispersity in Water + AOT +p-Xylene Microemulsions. A Dynamic Light-scattering Study, I I73 Semiconductors Visible-light-induced Photodissolution of a-Fe,O, Powder in the Presence of Chloride Anions, 1883 Metal-organic Chemical Vapour Deposition (MOCVD) of Compound Semiconductors.Part 1 .-Optimisation of Reactor Design of the Preparation of ZnSe, 27 1 1 Properties of Germanium-substituted Fe,O, Single Crystals, 1263 Preparation, Characterization and Photoelectronic Silica Nuclear Magnetic Resonance and Dielectric Relaxation Investigations of Water Sorbed by Spherisorb Silica, 847 Tin Oxide Surfaces. Part 14.4nfrared Study of the Adsorption of Ethane and Ethene on Tin(rv) Oxide, Tin(1v) Oxide-Silica and Tin(1v) Oxide-Palladium Oxide, 13 1 1 Tin Oxide Surfaces. Part 15.-Infrared Study of the Adsorption of Propene on Tin(1v) Oxide, Tin(1v) Oxide-Silica and Tin(iv) Oxide-Palladium Oxide, 1329 Tin Oxide Surfaces. Part 16.-Infrared Study of the Adsorption of Formic Acid, Acry!ic Acid and Acrolein on Tin(rv) Oxide, Tin(1v) Oxide-Silica and Tin(1v) Oxide-Palladium Oxide, 1345 Molecular Diffusion in Monolayer Films of Water Adsorbed on a Silica Surface, 2067 Insertion of Aluminium into High-silica-content Zeolite Frameworks.Part 3.-Hydrothermal Transfer of Aluminium from Al,O, into [AlIZSM-5 and [BIZSM-5,2215 Adsorption of n-Alkylpolyethylene Glycol Non-ionic Surfactants from Aqueous Solution on to Silica, 2235 An In Situ Mossbauer Investigation of the Influence of Metal-Support and Metal-Metal Interactions on the Activity and Selectivity of Iron-Ruthenium Catalysts, 2293 Spectroscopic Characterization of a Molybdena/Silica System Photoreduced in a Carbon Monoxide Atmosphere, 2307 Small-angle Neutron-scattering Studies of Silica Sols in Water at High Temperatures, 2845 Enthalpies of Adsorption of Non-ionic Surfactants from Aqueous Solutions on to Silica, 3 109 Silica Gel Linear Isotherms in Multicomponent Adsorption onto Silica Gel from Organic Solvents, 185 Capillary-condensed Water in Silica Gel, 597 Experimental and Theoretical Investigation of the Kinetics of the Sorption of Water Vapour by Silica Gel, 2681 Silica Sols Studies of Electrical Double-layer Interactions in Concentrated Silica Sols by Small-angle Neutron Scattering, I 17 Silicate Minerals Bonding-state Characterization of the Constituent Elements of Silicate Minerals by X-Ray Photoelectron Spectroscopy, 485SUBJECT INDEX xxiii Silicate Minerals (cont.) Quasi-elastic Neuron-scattering Studies of Intercalated Molecules in Charge-deficient Layer Silicates.Part 2.-High-resolution Measurements of the Diffusion of Water in Montmorillonite and Vermiculite, 833 Silicon Alkoxide A Shape-selective Platinum-loaded Mordenite Catalyst for the Hydrocracking of Paraffins by the Chemical Vapour Deposition of Silicon Alkoxide, 2757 Silicon Tetrachloride Preparation of High-silica Faujasites by Treatment with Silicon Tetrachloride, 2889 Silver Enthalpies and Entropies of Complexation of Cryptand 222 and Metal Ions in Propylene Carbonate and Acetonitrile.Derived Thermodynamic Parameters for the Transfer of Metal-ion Cryptates, 78 1 Kinetics of the Oxidation of 2-H ydroxy-2-methylpropanoic Acid by Silver(I1) Ions Complexed with 2,2’-Bipyridine in Aqueous Nitrate Media, 10057 Silver Malonate The Thermal Decomposition in the Solid Phase (Crystolysis) of Silver Malonate, 2503 Single Ion Conductances Comments on Gill’s Approach to the Evaluation of Single Limiting Ionic Conductances in Organic Solvents, 24 1 Singlet Oxygen Phoyochemical Generation of Singlet Oxygen on Non-transition-metal Oxide Surfaces, 793 Small- Angle Neutron Scattering Studies of Electrical Double-layer Interactions in Concentrated Silica Sols by Small-angle Neutron Scattering, 1 17 sodium Ion Exchange in Zeolites.The Exchange of Cadmium and Calcium in Sodium X Using Different Anionic Backgrounds, 173 1 Sodium Bicarbonate Electrochemical Reduction of Bicarbonate Ions at a Bright Palladium Cathode, 7 13 Sodium Carbonate Monohydrate Dehydration of Sodium Carbonate Monohydrate, 1761 Sodium Chloride Liquidus Measurements and Coupled Thermodynamic-Phase-diagram Analysis of the NaCl-KCl System, 1 167 Sodium Iodide Calorimetric Investigation of NaI-Alcohol Interactions in Alcohol + Alcohol Mixtures, 1913 Sodium Lauryl Sulphate Investigations of the Dynamic Behaviour of Counterions of Anionic Micellar Systems by Fluorescence Quenching Experiments, 245 Sodium Polyacrylate Effect of Sodium Polyacrylate on the Properties of Dilute and Concentrated BaSO, Dispersions, 2635 Sodium Silicotungstate A Thermodynamic Study of the Preferential Interaction of the Polyoxometallate Electrolyte Na,SiW,,O,; 14H20 with Ethers in Aqueous Solution, 25 13 Sodium Taurodeox ycholate A Study of the Flexibility of Sodium Taurodeoxycholate Secondary Micelles in 0.8 mol dmP3 Sodium Chloride Solution, 2103 Preferential Solvation of Ions in Mixed Solvents.Solvation Part 4.-Preferential Solvation of Cu+ in Acetone + Acetonitrile and NJ-Dimethylacetamide + Acetonitrile Mixtures Using Conductance Measurements, 687 (H502)+ (H,O), Species, 1547 1-Naphthoic Acid from Water to Mixed Aqueous Solvents at 298 K, 1555 Solvation of Acetone in Protic and Aprotic Solvents and Binary Solvent Mixtures, 1963 Infrared Spectroscopic Studies of the So!vation of Aprotic Solvents and Ions in Methanol, 21 3 1 Solvation of Nitroxides, 2421 Ultrasonic Attenuation in Aqueous Solutions of a-, a- and y-Cyclodextrins, 2551 Relationship between the Entropy of Transfer of a Solute and the Thermodynamic Functions of Mixed Solvents, 2703 Solvation of Esters and Dialkyl Carbonates. 2775 Separation of the Effect of Solvent Structure on the Kinetics of Substitution Reactions into Contributions to the Initial and Transition States using Free Energes of Transfer.Kinetics of the Solvolysis of 1,2-Chlorothiocyanatobis( 1,2-diaminoethane)- cobalt(rr1) Ions in Water and Water + Propan-2-01 Mixtures, 1401 trans-Dichlorotetrapyridinecobalt(iI1) Ion in Water + Dimethyl Sulphoxide Mixtures, 2 145 The Pressure Effect on Strained Transition States. Correlation between Strain and Volume of Activation : Mechanistic and Synthetic Involvements, 243 7 trans-Dichlorobis( 1,2-diaminoethane)cobaIt(111) Ion in Water+ t-Butyl Alcohol Mixtures, 2475 Experimental and Theoretical Investigation of the Kinetics of the Sorption of Water Vapour by Silica Gel, 268 1 Solutions and Sorption Systems, 3 103 Solvent Relaxation and Proton Transfer in the Thermodynamic Functions for the Transfer of Solvol ysis Kinetics of the Solvoiysis of the Kinetics of the Solvolysis of the Sorption Concentration Dependence of Fickian Diffusivity in Space-charge Layers The Nature of the Surface Charge of Ionic Crystals, 703 Spectrophotometry Effects of Solvent on Stacking Interactions. A Spectrophotometric Study of Thionine Dimerization in H,O and D,O, 255 Effects of Pressure on Reversed Micellar Systems.xxiv SUBJECT INDEX Spectrophotometry (cont.) Rates of the Keto-Enol Transformation of Pentane-2,4-dione, 2287 spectroscopy Solvation of Acetone in Protic and Aprotic Solvents and Binary Solvent Mixtures, 1963 Spinels Structural Characterization of Cadmium-Copper Gallium Oxide (Cd,Cu,-,Ga,O,) Spinels, 1255 Spreading Pressires for Fatty-acid Crystals at the Spreading Pressure Air/Water Interface, 973 Stability Constants Potentiometric Studies of Some Lanthanum Stability Constants and Free Energies of Carboxylates at Constanti Ionic Strength, 983 Complexation of Metal-ion Cryptates in Nitromethane.Derived Parameters for the Extraction of Cations by Cryptand 222 from Water to Pure Nitromethane, 2495 Linear-scan and Cyclic Voltammograms, 2659 The Pressure Effect on Strained Transition States. Determination of Stability Constants using Steric Effects Correlation between Strain and Volume of Activation: Mechanistic and Synthetic Involvements, 2437 Strontium Fluoride Constant-composition Study of the Kinetics of the Dissolution of Strontium Fluoride in Aqueous Solution, 1833 Sulphate Ion "0 Nuclear Magnetic Resonance Study of the Rotational Motion of the Sulphate Ion in Aqueous Solution, 127 Superoxide Ion Oxygen Species Adsorbed on Ultraviolet-irradiated Magnesium Oxide, 2835 Supported Catalysts An In Situ Mossbauer Investigation of the Influence of Metal-Support and Metal-Metal Interactions on the Activity and Selectivity of Iron-Ruthenium Catalysts, 2293 Surface-enhanced Raman Scattering Intensely-scattering Phase in Surface-enhanced Raman Scattering by Cyanide on Gold Electrodes, 2 1 15 Scattering by Cyanide on Copper Electrodes, 2123 Surface Studies Chemical Origins of Surface-enhanced Raman Electron Spin Resonance Spectroscopy of Surface Species formed upon Adsorption of Nitrogen Oxides and Oxygen on High-surface-area NiO-MgO and CoGMgO Solid Solutions, 37 Infrared Spectroscopic Study of the Adsorption of Hydrogen and Carbon Monoxide on Highly Dehydroxylated Thoria, 21 5 Surface-tension Measurements Differences in Surface Tensions of Non-ionic Surfactant Solutions as Measured by the Drop-volume and Wilhelmy-plate Techniques, 2975 Surfaces The Nature of the Surface Charge of Ionic Crystals, 703 Phoyochemical Generation of Singlet Oxygen on Non-transition-metal Oxide Surfaces, 793 Relaxation Processes on Graphitic Surfaces.Part 1 .-In the Absence and Presence of Adsorbed 4He on Spheron and Grafoil with lncreasing Temperature. 1589 Relaxation Processes on Graphitic Surfaces. Part 2.-Adsorption of ,He on Spheron and Grafoil, 161 1 Spectroscopy of Alkaline-earth-metal Oxides.Part 2.-Dependences upon Temperature of Pre-activation for SrO, 2027 Interfacial Tension Minima in Comparison of the Surface Reactivity and Surfact ants Oil + Water + Surfactant Systems. Effects of Salt and Temperature in Systems containing Non-ionic Surfactants, 21 55 Transformations in Lyotropic Liquid-crystal Systems, 273 Thermodynamics of Ionic Surfactant Binding to Macromolecules in Solution, 885 Thermodynamics of Adsorption of 0-n-Dodecylpentaethylene Glycol and 0-n-Dodecyloctaethylene Glycol from Aqueous Solutions on to Graphitised Carbon, 1503 Non-ionic Surfactants from Aqueous Solution on to Silica, 2235 Apparent Molar Volumes for Aqueous Solutions of the Homologous Series of a-Dodec yl-w-h ydroxypol y(oxyethy1ene) Surfactants, C,,EOj ( j = 4, 5, 6, 8 and 12), and of C,,EO,, 2693 Lower Consolute Boundaries of a Poly(oxyeth1ene) Surfactant in Aqueous Solutions of Monovalent Salts, 2947 Differences in Surface Tensions of Non-ionic Surfactant Solutions as Measured by the Drop-volume and Wilhelmy-plate Techniques, 2975 Enthalpies of Adsorption of Non-ionic Surfactants from Aqueous Solutions on to Silica.3109 Tautomerism Structural Aspects of Certain Phase Adsorption of n-Alkylpolyethylene Glycol Effects of Pressure on Reversed Micellar Systems. Rates of the Keto-Enol Transformation of Pentane-2,4-dione, 2287 Determination of the Rate of Tautomerization of 1 -Phenylbutane- 1,3-dione (Benzoylacetone) using the Technique of Solubilization into Micelles, 294 1 Temperature-programmed Analysis Aspects of Temperature-programmed Analysis of some Gas-Solid Reactions.Part 1 .-Dispersion Effects in Temperature-programmed Bulk Reduction and Temperature-programmed Desorption, 2605 Temperature-programmed Desorption Adsorption and Conductivity Studies inSUBJECT INDEX xxv Temperature-programmed Desorption (cont .) Oxychlorination Catalysis. Part 5.-Temperature-programmed Desorption, 83 Temperature-programmed Desorption Studies of Alcohol Decomposition on Zinc Oxide. Propan-2-01, 3073 Tetrachloronitrobenzene Kinetic Electron Spin Resonance Investigation of the Monohydronitro Free Radical of 2,3,5,6-Tetrachloronitrobenzene, 1467 Interaction Parameters and the Equilibrium Tetrahydrofuran Anionic Polymerization of a-Methylstyrene in Tetrahydrofuran, 1745 N,N,N,N-Tetrameth ylbenzidine Photoionization of N,N,N’,N’-Tetramethylbenzidine in Dodecyltrimethylammonium Chloride Cationic Micelles under 337 nm Laster Irradiation, 1025 N,N,N’,N’-Tetramethylbenzidine and its Protonated Forms in Sodium Dodecyl Sulphate Anionic Micelles under 337 nm Laser Irradiation, 1669 Tetramethyltin Photochemical Behaviour of Thermodynamic Study of Tetramethyltin, Sn(CH,),, Absorbed on (0001) Graphite Planes, 2339 Thermal Decomposition Dehydration of Sodium Carbonate Monohydrate, The Thermal Decomposition in the Solid Phase Deammoniation and Dehydroxylation of Calcium 1761 (Crystolysis) of Silver Malonate, 2503 Ammonium Chabazites, 3049 Thermal Dissociation The Thermal Dissociation of Ethane.A Study of the Reaction over an Extended Pressure Range, 745 Thermal Expansion Coefficients Liquid Structure and the Thermal Pressure Coefficients of Cyclohexane +Normal- and Branched-alkane Mixtures, 387 Thermal Neutrons Chemistry of lZsl in Alkaline Aqueous Solutions of Sodium Iodate Activated by Thermal Neutrons, 2627 Thermodynamics Ionic Solvation in Water + Cosolvent Mixtures.Part 10.-Free Energies of Transfer of Single Ions from Water into Water + Ethanonitrile Mixtures, 1985 Enthalpies of Mixed-micelle Formation. 207 Enthalpy and Volume Changes on Mixing Diethylene Glycol Di-n-alkyl Ethers with Diethylene Glycol Dimethyl Ether or n-Alkanes, 223 Thermodynamics of Transfer of Noble Gases in Hydrophobic Solvents and in Phospholipid Membranes, 579 Thermodynamics of Cholesterol Self-association and its Interaction with Tripalmitin and L-u-Lecithin, 655 Calorimetric Investigations on Association in Ternary Systems.Part. 3.-Hydrogen-bonded Complexes in Phenol-Tetrahydrofuran Systems in CCl,, 695 Enthalpies and Entropies of Complexation of Cryptand 222 and Metal Ions in Propylene Carbonate and Acetonitrile. Derived Thermodynamic Parameters for the Transfer of Metal-ion Cryptates, 78 1 Macromolecules in Solution, 885 Potassium Metaborate, 91 3 Concentrations in Mixtures of Cyclohexane and 1,4-Dimethylbenzene, 1459 Excess Properties and Thermodynamics of Multicomponent Gas Adsorption, 1527 Thermodynamic Functions for the Transfer of 1-Naphthoic Acid from Water to Mixed Aqueous Solvents at 298 K, 1555 Polyelectrolyte Systems, 1677 Frictional Formalism of Non-equilibrium Thermodynamics, 1725 Calorimetric Investigation of NaI-Alcohol Interactions in Alcohol +Alcohol Mixtures, 191 3 Dynamic Study of the Interaction between Diols and Water by Ultrasonic Methods.Part 3.-2-Methylpentane-2,4-diol Solution, 193 1 Oil +Water + Surfactant Systems. Effects of Salt and Temperature in Systems containing Non-ionic Surfactants, 2 155 Interfacial Tension Minima in Oil + Water + Surfactant Systems. Effects of Salt, Temperature and Alkane in Systems containing Ionic Surfactants, 21 69 Sn(CH,),, Absorbed on (0o01) Graphite Planes, 2339 The Pressure Effect on Strained Transition States. Correlation between Strain and Volume of Activation : Mechanistic and Synthetic Involvements, 2437 A Thermodynamic Study of the Preferential Interaction of the Polyoxometallate Electrolyte Na,SiW,,O,, * 14H,O with Ethers in Aqueous Solution, 25 13 Relationship between the Entropy of Transfer of a Solute and the Thermodynamic Functions of Mixed Solvents, 2703 Binding of 2-Naphtholate Ions to a Water-in-oil Cetyltrimethylammonium Bromide Microemulsion.The Enthalpy and Entropy of Interaction, 2723 Thermodynamic-Phase-diagram Analysis of the NaCl-KCl System, 1 167 Molecular Structure and Orientational Order Effects in Enthalpies and Heat Capacities of Solute Transfer into n-Hexadecane. Part ,?.-Cyclic and Aromatic Solutes, 3037 Solute-Solvent Interactions in Water-t-Butyl Thermodynamics of Ionic Surfactant Binding to Electron-impact and Thermodynamic Studies of Thermodynamics of Ethanol at Low Thermodynamics of Ion-exchange Equilibria in Mutual Diffusion and Self-diffusion in the Interfacial Tension Minima in Thermodynamic Study of Tetramethyltin, Liquidus Measurements and Coupledxxvi SUBJECT INDEX Thermodynamics (con t .) Alcohol Mixtures. Part 14.-AGe, AH0 and A S 6 of Transfer for Alkaline-earth-metal Cations, 308 1 Multicomponent Ion Exchange in Zeolites.Part 2.-Prediction of Exchange Equilibria over a Range of Solution Concentrations, 3 127 A Thermokinetic Foundation for Oscillatory Thermokinetics Phenomena in Gaseous Organic Oxidations under Well Stirred Flowing Conditions, 343 Effects of Solvent on Stacking Interactions. A Thionine Spectrophotometric Study of Thionine Dimerization in H,O and D,O, 255 The Rotating Optical Disc-Ring Electrode. Part 1 .-Collection of a Stable Photoproduct, 2647 Infrared Spectroscopic Study of the Adsorption of Thorium Oxide Hydrogen and Carbon Monoxide on Highly Dehydroxylated Thoria, 21 5 Tin oxide Tin Oxide Surfaces.Part 14.--Infrared Study of the Adsorption of Ethane and Ethene on Tin(iv) Oxide, Tin@) Oxide-Silica and Tin(1v) Oxide-Palladium Oxide, 13 1 1 Tin Oxide Surfaces. Part 15.-Infrared Study of the Adsorption of Propene on Tin@) Oxide, Tin@) Oxide-Silica and Tin(rv) Oxide-Palladium Oxide, 1329 Tin Oxide Surfaces. Part 16.-Infrared Study of the Adsorption of Formic Acid, Acrylic Acid and Acrolein on Tin(1v) Oxide, Tin@) Oxide-Silica and Tin(1v) Oxide-Palladium Oxide, 1345 Titanium Dioxide Correlation of the Crystal Structure of Titanium Dioxide Prepared from Titanium Tetra-2-propoxide with the Photocatalytic Activity for Redox Reactions in Aqueous Propan-2-01 and Silver Salt Solutions, 61 Radicals on Colloidal TiO,, 143 2.-A Photogalvanic Cell Based on TiO, Semiconductor Colloid, 509 Formation and Stability of Ru"' Incorporated in TiO, (Rutile), 8 13 Surface Characterization of a Grafted Vanadium-Titanum Dioxide Catalyst, 1003 Photocatalytic Dehydrogenation of Aliphatic Alcohols by Aqueous Suspensions of Platinized Titanium Dioxide, 2467 Titanium Dioxide, 1237 Deposited by Vapour-phase Decomposition of Isopropyl Titanate, 3 1 17 Electron Transfer and Dimerization of Viologen Photoelectrochemistry in Colloidal Systems.Part Photolysis of Water over Metallized Powdered Rutile Growth at the Surface of TiO, Films Topochemistr y Study of the Crystal and Molecular Structure of the 9-Cyanoanthracene trans Dimer and of its Monomerisation, 857 Transition N-static Tbeory Pressure Dependence of Activation and Reaction Volumes, 875 Transition-State Theory Kinetics of the Reaction between Cyanide Ions and Tris(4-methyl- 1,l O-phenanthroline)iron(u) Cations in Aqueous Solutions. Analysis of Kinetic Data for this Reaction and for Solvolysis of Benzyl Chloride in Water in Terms of Isothermal, Isobaric and Related Isochoric Activation Parameters, 1 1 Solutions and Sorption Systems, 3103 Concentration Dependence of Fickian Diffusivity in Transport Phenomena Concentration Dependence of Electrokinetic Transport Coefficients of Non-aqueous Binary Mixtures through Weakly Charged Porous Plugs, 609 Trifluoroacetic Acid Broad Single-minimum Proton Potential and Proton Polarizability of the Hydrogen Bonds in Trifluoroacetic Acid + Pyridine-N-Oxide Systems as a Function of Donor and Acceptor Properties and Environment.Infrared Studies, 1425 Trifluoroacetyl Radical Kinetic Study of the Gas-phase Decomposition of the Trifluoroacetyl Radical. Effects of Temperature and Pressure upon the Rate Constants, 147 1 Trinitrobenzene A Kinetic Study of the Formation and Dissociation of the Meisenheimer Complex Formed between 1,3,5-Trinitrobenzene and the Hydroxide Ion in Micellar Dodecyltrimethylammonium Bromide Solution, 335 Trinitrotoluene Kinetic Hydrogen Isotope Effects in the Reaction between 2,4,6-Trinitrotoluene in I-Ethylpiperidine in Acetonitrile. The Effect of Pressure, 2959 Tris(2,2'-bipyridine)ruthenium(II) Photochemistry of Compounds Adsorbed into Cellulose.Part 4.-Diffusion-controlled Mechanism of Ru(bpy),2+ Luminscence Quenching by Copper(II), 735 Tungsten Oxide Activity of Supported Tungsten Oxide Catalysts for the Metathesis of Propene, 1705 Tunnelling Substituent Effects on Proton Tunnelling. Reaction between 2,4,6-Trinitrotoluene and l-Substituted Piperidines in Acetonitrile, 1441 Ultrasonic Absorption Dynamic Study of the Interaction between Diols and Water by Ultrasonic Methods. Part 3.-2-Methylpentane-2,4-diol Solution, 193 1 Ultrasonic Attenuation Ultrasonic Attenuation in Aqueous Solutions of a-, /?- and y-Cyclodextrins, 2551 Ultraviolet Spectroscopy Ultraviolet-Visible Spectrophometric Study of N-Alkylpyridinium Iodides in Non-aqueous Solvents, 2323 Ultraviolet-Visible Spectroscopy Binding and Decomposition of Oxovanadium(1v) Phthalocyanine, Tetraphenylporphyrin and Etioprophyrin on Hydrotreating CatalystsSUBJECT INDEX xxvii Ultraviolet-Visible Spectroscopy (cont.) Studied by X-Ray Photoelectron and Ultraviolet-Visible Spectroscopies.Relevance to Catalytic Demetallisation, 1047 Spectroscopic Study of the Cokefaction of Butene and Butane on Alumina, 497 Ultraviolet-Visible Spectrophotometric Determination of Ion-association Constants for A1 kylpyridinium Iodides. N-Ethyl-4cyanopyridinium Iodide in Mixed Solvents Containing Ethanol, 961 Binding of 2-Naphtholate Ions to a Water-in-oil Cetyltrimethylammonium Bromide Microemulsion. The Enthalpy and Entropy of Interaction, 2723 Kinetics and Equilibria in Pentacyanoiron(I1) Systems, 302 1 Influence of Cationic Polyelectrolytes on the Unimolecular Decomposition Thermal Unimolecular Decomposition of P-Propiolactone (Oxetone-2-one), 1087 Uracil Reactions of Cobalt(nr) Compounds with some Free Radicals Derived from Uracil, 2569 Uranium Photphysics of the Excited Uranyl Ion in Aqueous Solutions. Part 5.-Fluorescence Quenching by Micellar Solutions of Triton X- 100, 1891 Oxide Catalysts, 1121 Electrical Conductivity of Uranium-Antimony Uranyl Ion Photophysics of the Excited Uranyl Ion in Aqueous Solutions.Part 4.-Quenching by Metal Ions, 49 Vanadium Surface Characterization of a Grafted Vanadium-Titanum Dioxide Catalyst, 1003 Characterization of Silica-supported Vanadium Species. Interactions with Methanol and Ammonia Adsorbates Studied by Electron Spin-Echo Modulation Spectrometry, 137 Ab Inisio Molecular-orbital Study on the Adsorption of Ethylene and Oxygen Molecules over Vanadium Oxide Clusters, 15 13 Liquid Structure and the Thermal Pressure Vanadium Oxide Velocities of Sound Coefficients of Cyclohexane + Normal- and Branched-alkane Mixtures, 387 Viologen Radicals Electron Transfer and Dimerization of Viologen Radicals on Colloidal TiO,, 143 Viscometry Structural Study of Microemulsions of Glycerol Stabilised by Cetyltrimethylammonium Bromide Dispersed in Heptane + Chloroform Mixtures, 2053 Viscosity B Coefficients Separation of Viscosity B Coefficients into Ionic Contributions.Part 4.-Extrapolation Methods Using Tetra-alkylammonium Bromides in Dimethyl Sulphoxide and Hexamethylphosphoric Triamide, 1 133 Visible Adsorption Spectroscopy Formation of the m-Dinitrobenzene Radical-anion Dimer in the Triplet Ground State on Magnesium Oxide, 1755 Volume Changes Measurements of Volume Changes on the Formation of Precipitates of Carbonates and Phosphates of Cadmium(i1) and Calcium(n) in Aqueous Solutions, 2333 Volumes Apparent Molar Volumes for Aqueous Solutions of the Homologous Series of a-Dodecyl-o-hydroxypoly( oxyethylene) Surfactants, C,,EO, ( j = 4, 5, 6, 8 and 12), and of C,,EO,, 2693 Volumetric Studies Neutron-sdcattering and Volumetric Study of Hydrogen Adsorbed and Absorbed on Raney Palladium, 1955 Self-diffusion and Volumetric Measurements for N- Me t hylformamide and N,N-Dimethylformamide at Temperatures from 240 to 3 13 K and Pressures up to 300 MPa, 282 1 Water Aqueous Solutions.Part 2.-The Compressibility and Acoustic Relaxations of Water, 1 Aqueous Solutions. Part 3.-Thermal and Acoustic Characteristics of Water, 5 19 Heat Capacities of Water + Organic-solvent Mixtures, 238 1 Photo-oxidation of Water using Prussian Blue as Catalyst, 2461 Experimental and Theoretical Investigation of the Kinetics of the Sorption of Water Vapour by Silica Gel, 268 1 Photolysis of Water over Metaliized Powdered Titanium Dioxide, 1237 Ionic Solvation in Water-Cosolvent Mixtures. Part 1 1 .-Free Energies of Transfer of Single Ions from Water into Water-Urea Mixtures, 309 1 X-Ray Diffraction Formation and Stability of Ru"I Incorporated in X-Ray-diffraction Analysis of the Molten Synthesis and Luminiscence of Ruthenium TiO, (Rutile), 813 ZnC1,-KC1 System, I90 1 Tris(2,2'-bipyridine)-Zirconium Phosphates, 2009 Non-ionic Surfactants from Aqueous Solution on io Silica, 2235 Physicochemical Properties of LaFeO,. Kinetics of Reduction and of Oxygen Adsorption, 2399 Studies of the Effect of Calcination on the Dispersion and Reduction of Nickel Supported on Alumina by X-Ray Photoelectron Spectroscopy, X-Ray Diffraction, Chemisorption and Catalytic Activity, 2733 Hydrogen Sorption by a Supersaturated Solution of Carbon in Palladium, 28 13 Preparation of High-silica Faujasites by Treatment with Silicon Tetrachloride, 2889 Adsorption of n-Alkylpolyethylene Glycolxxviii SUBJECT INDEX X-ray diffraction (cont.) Structural Characterization of Cadmium-Copper Gallium Oxide (Cd,Cu,~,Ga,O,) Spinels, 1255 Bonding-state Characterization of the Constituent X-Ra y Photoelectron Spectroscopy Elements of Silicate Minerals by X-Ray Photoelectron Spectroscopy, 485 Spectroscopy Study on the Rhodium-Carbonate Electrode in Molten Nitrates, 621 Binding and Decomposition of Oxovanadium(1v) Phthalocyanine, Tetraphenylporphyrin and Etioprophyrin on Hydrotreating Catalysts Studied by X-Ray Photoelectron and Ultraviolet-Visible Spectroscopies.Relevance to Catalytic Demetallisation, 1047 Decomposition of N,O on Fe,O,/Al,O, Catalysts. Relationship between Physicochemical and Catalytic Properties, 2043 Surface Reduction of some Transition-metal Oxide. An X-ray Photoelectron Spectroscopic Study of Iron, Cobalt, Nickel and Zinc Oxides, 2 179 Studies of the Effect of Calcination on the Dispersion and Reduction of Nickel Supported on Alumina by X-Ray Photoelectron Spectroscopy, X-Ray Diffraction, Chemisorption and Catalytic Activity, 2733 Carbon-fibre Surfaces.Part 5.-The Effect of pZ1 on Surface Oxidation, 2745 A Shape-selective Platinum-loaded Mordenite Catalyst for the Hydrocracking of Paraffins by the Chemical Vapour Deposition of Silicon Alkoxide, 2757 Electrochemical and Surface X-ray Photoelectron X-Ray Photoelectron-spectroscopic Studies of X-Ray Scattering X-Ray Scattering Structural Investigation of Pt and Pt-Sn Catalysts Supported on Nylon, 32 1 Zeolites Insertion of Aluminium into High-silica-content Zeolite Frameworks. Part 3.-Hydrothermal Transfer of Aluminium from A1,0, into [Al]ZSM-5 and [B]ZSM-5,2215 Modifications.Part 2.--Ion-exchange Properties of Thermally Treated Ammonium Forms, 299 The Catalytic Cracking of Cumene Stidied by Reversed-flow Gas Chromatography, 95 1 Multicomponent Ion Exchange in Zeolites. Part 1 .-Equilibrium Properties of the Study of Small-port and Large-port Mordenite Sodium/Calcium/Magnesium-Zeolite A System, 1071 Crystallization Field of Zeolite T at 100 "C for a SiO,/Al,O, Ratio of 28 and Crystallization Sequences in the Na,O-K,O-SiO,-Al,O,-H,O System, 1297 Influence of Support Acidity and Ce3+ Additives on the Reactivity of Nickel Particles Highly Dispersed on Various Oxide Supports, 1357 Silicon-29 Magic-angle-spinning Nuclear Magnetic Resonance Study of the Crystalline-Amorphous Transition of Zeolite A Containing Trapped Krypton, 1435 Ion Exchange in Zeolites.The Exchange of Cadmium and Calcium in Sodium X Using Different Anionic Backgrounds, 173 1 Infrared Spectroscopic Investigation of Hydroxy-group Siting in H Faujasites, 2257 Adsorption of Methylamines on Dehydrated NaX, NaY and KY Zeolites, 2525 Microdynamics of Methane, Ethane and Propane in ZSM-5 Type Zeolites, 2541 Preparation of High-silica Faujasites by Treatment with Silicon Tetrachloride, 2889 Catalytic Properties of H Mordenite Modified with Fluorine, 1 16 1 High-resolution Solid-state Nuclear Magnetic Resonance Studies of Dealuminated Zeolite Y, 3003 Deammoniation and Dehydroxylation of Calcium Ammonium Chabazites, 3049 Multicomponent Ion Exchange in Zeolites. Part 2.-Prediction of Exchange Equilibria over a Range of Solution Concentrations, 3127 Zinc Oxide Surface Reduction of some Transition-metal Oxide.An X-ray Photoelectron Spectroscopic Study of Iron, Cobalt, Nickel and Zinc Oxides, 21 79 Infrared Studies of Intermediates in the Oxidation of Propene on ZnO using l8OZ, 2409 Temperature-programmed Desorption Studies of Alcohol Decomposition on Zinc Oxide. Propan-2-01, 3073 Zirconium Phosphate Intercalation of n-Alkylamines by a-Zirconium Synthesis and Luminiscence of Ruthenium Phosphate, 545 Tris(2,2'-bipyridinekZirconium Phosphates, 2009Author Index Abdel-Kader, M. H., 245 Abdullah, P. B., 983 Akitt, J. W., 1923, 193 Al-Kafaji, J. K. H., 223 Albery, W. J., 2647, 1999 Ali, J., 3037 Alzamora, L., 1631 Amire, 0. A., 2723 Anderson, R. A., 821 Anderson, J. Y., 2681 Andreini, A., 1705 Andreoli-Ball, L., 3037 Andres, J.L., 1547 Antoniou, A. A., 1589, 161 1 Arce, R., 1025, 1669 Ariffin, Z., 223 Ashworth, A. J., 473 Augustynski, J., 713 Aveyard, R., 2169, 2155 Awan, I. A., 1415 Azoulay, M., 2681 BaEiC, S., 1275 Bagchi, S., 961, 2323 Bai, L., 1841 Baiker, A., 2797 Ball. M. C., 1761 Balon, M., 1555 Barczynska, J., 3081 Barouch, E., 1797, 1819 Bartlett, P. N., 2647 Basilevsky, M. V., 875 Battaglin, G., 2995 Baugh, P. J., 3067 Baulch, D. L., 259 Baumgartner, E., 11 13 Becker, K. A., 1161 Belenkaja, I. M., 3049 Belenykaja, I. M., 2889 Bennett, C. O., 19 Berry, F. J., 2293 Bertran, J., 1547 Bettelheim, A., 1577 Beyer, H. K., 3049, 2889 Bhattacharyya, N., 3037 Bhattacharyya, S . N., 387, 375, Bicknell R. T. M., 1133 Binks, B. P., 2155, 2169 Bjorklund, R. B., 1715 Bjurstrom, H., 2681 Blackburn, G.M., 2207, 2191 Blandamer, M. J., 1495, 2357, Blesa, M. A., 11 13, 3021 Bloemendal, M., 1015 Bohner, U., 1425 2569 11 Boij, K., 1015 Bone, S., 537 Bonnelle, J-P., 1047 Booth, C . , 223 Borbely, G., 3049 Borgareilo, E., 143 Borghi, E. B., 3021 Boucher, E. A., 919, 2787 Bowker, M., 3073 Braun, A. M., 245 Brazdil, J. F., 1693, 2903 Brener, R., 2339 Brereton, I. M., 1623 Brown, G. T., 1999 Brown, R., 1871 Brzezinski, B., 2375 Bucci, C., 433 BufFham, B. A., 161 Bui, V. T., 1745 Bulow, M., 2541 Bunce, J., 2845 Burgess, J., 11, 1495, 2357 Burrows, H. D., 2723, 49 Bury, R., 2513 Busca, G., 1003 Buxton, G. V., 449, 3067 Campbell, I. M., 259 Candy, J-P., 1955 Cardoso, A. C., 49 Carlsson, B., 2681 Carnera, A., 2995 Caro, J., 2541 Carroll, B.J., 2975 Catterall, R., 3067 Cavinato, A. G., 621 Centi, G., 1003 Chang, C. D., 2215 Chary, K. V. R., 1655 Chauhan, M. S., 687 Chengyu, W., 2293 Christensen, P. A., 2461 Chung, J. S., 19 Cichocki, A., 1297 Clark, B., 11, 2357 Clark, J. W., 2067 Clarke, J. H. R., 1173 Clayden, N. J., 1435 Clearfield, A., 545 Coates, J. H., 1247 Cocco, G., 321 Cochran, S. J., 2179 Cohen, H., 233 Cohen, L. H., 1789 Conway, B. E., 1841 Cooney, R. P., 21 15, 2123 Cope, J., 223 xxix Cordischi, D., 37, 813 CortCs, J., 1637, 1631 Costas, M., 635, 655, 2381, 387 Cox, S. F. J., 433 Cronin J. A., 2027 Csanyi, L. J., 113 Cunningham, J., 2027 Dagnall, S. P., 1483 D’Alba, F., 421 Danil de Namor, A. F., 781, Darvel, B. W., 1647 Darwent, J. R., 1999 Davidson, R. S., 1883 Davidsson, A., 1375 Davies, J.I., 271 1 de Menorval, L-C., 2867, 2855 de Renzi, R., 433 de Schrijver F. C., 2009 de Valera, E., 2703 de Vijlder, M., 1369 Delafosse, D., 1357 Della Mea, G., 2995 Dell’Atti, A., 1133 Derkaui, A., 1685 Desimoni, E., 621 Di Lorenzo, S . , 421 Diez Viiiuela, J. S., 1255 Djega-Mariadassou, G., 1357 Dobson, C. M., 1435 Dobson, J. V., 1863 Dombrowski, D., 2257 Donegan, A. C., 2975 Dongbai L., 2293 Doyle, P. J., 2975 Duffy, J. A., 265 Duran, M., 1547 Easteal, A. J., 769, 2821 Eastland, G. W., 727 Eaton, G., 1963, 2775 Eid, A. E., 1401 Elders, J. M., 1923 Eley, D. D., 2981 Elgy, C. N., 2145 Ellis, D. K., 545 Enzo, S., 321 Escalona Platero, E., 1255 Evans, G. J., 673 Evans, M. J. B., 919, 2787 Fan, G., 271 1 Farber, M., 913 Farnsworth, J.A., 193 Feakins, D., 2703 Febbraro, S., 37 Fenin, V. A., 2913 Fernandez-Prini, R., 3021 2495xxx Fiedler, K., 3103 Fierro, J. L. G., 2399, 1203 Flanagan, T. B., 2921 Fleisher, Z., 241 Fletcher, P. D. I., 2053, 2667 Fletcher, P., 1731 Flowers, M. C., 1415 Formosinho, S. J., 49, 1891 Fornili, S. L., 255 Fournier, M., 2513 Fraissard, J., 2855, 2867 Franklin, K. R., 1071, 3127 Freedman, R. B., 2667 French, H. T., 1459 Freund, E., 215, 299 Frey, H. M., 1087 Fromon, M., 2513 Fruwert, J., 2257 Funabiki, T., 2485 Fyfe, C. A., 3003 Gaboriaud, R., 335 Gabriel, A., 1167 Galal, M. F., 2053 Galbacs, Z. M., 113 Galvagno, S., 321 Galwey, A. K., 2503 Garbowski, E., 497 Garfinkle, M., 717 Gazzoli, D., 813 Gellan, A., 1503, 2235, 3109 German, E. D., 1153 Gethner, J. S., 991 Getoff, W., 1101 Ghousseini, L., 781, 2495 Giamello, E., 2307 Gill, D.S., 687 Glaeser, L. C., 2903 Gobbi, G. C., 3003 Gohre, K., 793 Golunski, S. E., 1121 Gbralski, P., 695 Grasselli, R. K., 1693, 2903 Gratzel, M., 1883 Gray, B. F., 1563 Grech, E., 3 1 1 Griffith, T. R., 821 Griffiths, J. F., 343 Grimblot, J. G., 1047 Gritzner, G., 2875 Grobet, P. J., 2889 Groves, G. S., 1985, 2475, 3091 Gu, T., 185 Guglielminotti, E., 2307 Guilleux, M-F., 1357 Gutsche, R., 3103 Guveli, D. E., 2103 Hague, D. N., 1483 Hakin, A. W., 2357 Hall, D. G., 885 Hall, P. G., 2067, 69, 83, 847 Hall, P. L., 833 Hamza, S . M., 1833 Hange, F., 2889 Hann, R. A., 69 Harriman, A., 2461 AUTHOR INDEX Harrison, P. G., 131 1, 1329, Harrop, R., 2635 Harth, D., 1577 Hashitani, T., 2333 Hasko, S.M., 343 Hayes, M. H. B., 833 Hayter, J. B., 833 Hazle, M. A., 2903 Heaton, P., 69, 83 Heelis, P. F., 1225 Heink, W., 2541 Hellring, S. D., 2215 Herrington, T. M., 2693 Herrmann, J-M., 2107 Hey, M. J., 207 Heyward, M. P., 10057 Hidalgo-Alvarez, R., 609 Hill, A., 433 Hoffmann, J., 2257 Holoman, J., 1101 Honig, E. P., 703 Hoyle, N. D., 2605 Hronec, M., 2095 Hucknall, D. J., 1121 Hurle, R. L., 769 Hyett, M. W., 2357 Ihara, S., 2525 Iizuka, T., 1755 Ikemoto, I., 2835 Indelli, A., 2967 Indovina, V., 37 Ito, T., 2855, 2867, 2835 Iwahashi, M., 973 Izzo, V., 255 Jackson, S. D., 2225 Jacobs, P. A., 2889, 3049 Jamieson, E. W., 1871 Javier de la Nieves, F., 609 Jenner, G., 2437 Jobic, H., 1955 Johansson, L. B-A., 1375, 1389 Jones, W., 857 Juillard, J., 308 1 Juszczyk, W., 1447 Kagiya, T., 61, 2467 Kajiwara, H., 61 Kalenik, J., 3 1 1 Kamat, P.V., 509 Kaneko, Y., 973 Kanellopoulos, N. K., 1183 Karger, J., 2541, 3103 Karpinski, Z., 1447 Karvaly, B., 1939 Kato, M., 2835 Katsanos, N. A., 951 Katz, Y., 579 Kawarnura, S., 2805 Kawashima, Y., 2757 Kazansky, V. B., 29 13 Kemball, C., 1871 Kemeny, G., 1939 Kent, H. E., 2207 Kerr, J. A., 1471 Kevan, L., 137, 1025, 1669, 2083 1345 Killa, H. M., 2659 Kiselev, A. V., 1685 Kita, H., 175 Kittaka, S., 2525 Kiwi, J., 1883 Klement, W. Jr, 1789 Klepping A. H., 2981 Klinowski, J., 3003, 1435 Klofutar, C., 1141 Knoche, W., 2551 Kobayashi, H., 1513 Kordulis, C., 2043 Kornhauser, I., 2931 Kotinopoulos, M., 951 Kowalak, S . , 1161 Kozlowski, C., 2745 Kraml, G., 2875 Krebser, P., 2273 KremeniC, G., 939 Kremer, M.L., 91 Kronberg, B., 3037 Krumgalz, B. S., 241 Krzemien, U., 695 Kubokawa, Y., 2409 Kuhn, A. T., 403 Kuji, T., 2921 Kurnari, N., 687 Kuroda, Y., 757 Kurotaki, K., 2805 Kuznetsov, A. V., 2913 Kuznetsov, B. V., 1685 Larnotte, J., 21 5 Land, E. J., 1225 Larkins, F. P., 2 179 Larotonda, R., 11 13 Lavalley, J-C., 215 Lawless, T. A., 2155 Lawrence, K. G., 1133 LaziC, S., 1275 Lee, W. H., 2495 Leeper, J. D., 913 Lelievre, J., 335 Leng, C. A., 2693 Leonard, J., 1745 Letellier, P., 193 Leyendekkers, J. V., 1, 519 Lilley, T. H., 2191, 2207 Lim, T-K., 1195 Lincoln, S. F., 1247, 1623 Lindblom, G., 1389 Lithgow, A. M., 2647 Liu, X., 1435 Liwu, L., 2293 Lledos, A., 1547 Lodi, G., 2995 Lopez Agudo, A., 1203 Lorenzelli, V., 215 Lundstrom, I., 1715 Lycourghiotis. A., 2043 MacDiarmid, A.G., 105 Machin, W. D., 597 MacTaggart, J. W., 207 Maehara, N., 973 Maestre, A., 1555 Magonski, J., 2021AUTHOR INDEX xxxi Mahoney, M. R., 21 15, 2123 Mallik, B., 1939 Mammone, R. J., 105 Mandal P. C., 2569 Marchetti, L., 1003 Marcilly, C., 299 Maroto, A. J. G., 11 13 Marti, €3-R., 2273 Maruthamuthu, P., 1979 Mason, G., 161 Masuda, Y., 127 MatijeviC, E., 1797, 1819 Maunders, B., 131 1, 1329, 1345 Mayagoitia, V., 293 1 NcAdam, M. E., 1483 McDonald, M. P, 273 Mead, J., 2155, 2169 Medley, M., 3067 Mehicic, M., 2903 Meisel, D., 143 'Melikhov, I. V., 1275 Meyerstein, D., 233 Miale, J. N., 2215 Middleton, S. R., 973 Miguel, M. da G. M., 49 Miguel, M-G. M., 1891 Milburn, P. J., 2191 Miller, G. C., 793 Milosavljevic, B. H., 735 Miranda, R., 19 Mirti, P., 2365 Mishra, S.P., 2627 Mitchell, P. C. H., 1047 Miyaka, Y., 2941 Miyata, H., 2409 Mohamed, M. A., 2503 Mokrzan, J., 3081 Mol, J. C., 1705 Monk, C. B., 983 Moore, P. B., 2981 Moreton, A. D., 1483 Morishige, K., 2525 Morrison, C. L., 1883 Moyer, J. W., 913 Mulac, W. A., 143 Mufiiz, M. A., 1547 Murakami, Y., 2757 Myers, A. L., 355 Nag, N. K., 1655 Nakajima, T., 2409 Nakamura, T., 1901 Nakao, N., 1931 Nancollas, G. H., 1833 Narasimhan, C. S., 137 Narayana, M., 2083, 137 Nardyanan, S., 2733 Narkiewicz-Michalek, J., 553 Nasu, M., 3117 Natarajan, P., 2763 Nazar, A. F. M.. 801 Neta, P., 2461 Neumann-Spallart, M., 601 Nevell, T. G., 1121 Newbatt, P. H., 2605 Nicholson, D., 1183 Nicholson, J. D., 1173 Nieto, J. y. L., 939 Nikitas. P., 1767 Nishikawa, S., 1931 Nishimoto, S-I., 61 Nishimoto, S., 2467 Niwa, M., 2757 Novich, B. E., 1455 Nunan, J., 2027 O'Brien, J . A., 355 Bcchiuzzi, M., 37 Ogura, K., 267, 1569 Ohtani, B., 61, 2467 Olabe, J. A., 3021 Oldfield, C., 2667 Oliver, J. A., 1871 Opriel, U., 397 Otero Arean, C., 1255 Ozer, D., 1577 Paillous, N., 245 Pal, M., 961, 2323 Paljk, s., 1141 Pallas, N. R., 973 PaIumbo, L., 255 Pardo, G., 609 Parsons, B. J., 1225 Pasteris, L., 1303 Pdtel, K. B., 2775 Patterson, D., 375, 387, 635, 655, 238 1, 3037 Pawlak, Z., 2021 Pelizzetti, E., 143 Pelton, A. D., 1167 Pena-Niiiez, A. S., 2421 Penfold, J., 2845, 117 Peng, G-Z., 545 Penzhorn, R. D., 1435 Perez-Camino, M. C., 1555 Perrichon, V., 1955 Pethica, B. A., 973 Pethig, R., 537 Petropoulos, J. H., 1183 Petts, R. W., 3073 Peuckert, M., 2797 Pfeifer, H., 2541 Phillips, G. O., 1225 Pidduck, A. J., 2067 Pidgeon, I. M., 1087 Piekarska, A., 1913 Pietropaolo, R., 321 Pilorz, K., 553 Pires, M. J., 2107 Pisaniello, D. L., 1247 Platero, E. E., 1283 Poltarzewksi, Z., 321 Pomonis, P., 2043 Portela, M. F., 2107 Price, G. J., 473 Primet, M., 497, 2855, 2867 Puchalska, D., 1037 Raatz, F., 299 Rajaram, R. R., 2577, 2593 Ramaraj, R., 2763 Ramsay, J. D. F., 2845, 117 Randle, K. J., 285 Randle, T. H., 403 Rao, D. N. R., 565, 727 Rarity, J. G., 285 Rastogi, R. P., 751 Rauh, S., 2551 Reddy, B. M., 1655 Regan, K. N., 1173 Renouprez, A., 1955 Renyuan, T., 2293 Riefkohl, J., 2647 Ring, T. A., 1455 Robertson, R. E., 11 Robinson, B. H., 2053, 2667 Robinson, H.L., 2131 Rochester, C. H., 207, 1503, 2235, 1203, 3109 Rojas, F., 2931 Rollins, K., 2605 Romero, L., 2647 Ross, D. K., 833 Rosseinsky, D. R., 69, 83 Rudan-TasiE, D., 1141 Rudzinski, W., 553 Rys, P., 2273 Sabbatini, L., 621 Sacco, A., 1133 Sahi, S. S., 2693 Saievar-Iranizad, E., 1999 Salmon, G. A., 3067 Sanchez, C., 1263 Sanchez, E., 1555 Sangster, J., 1167 Sano, M., 127 Sasaki, M., 1441, 2959 Sato, S., 1237 Saunders, S. M., 259 Sauvion, G-N., 1357 Scandola, F., 2967 Scandola, M. A. R., 2967 Schirmer, W., 2541 Schlosserova, J., 2095 Schmitt, K. D., 2215 Schoonheydt, R. A., 2009 Schuster, P., 1435 Scott, C. A., 433 Scott, C. E., 1047 Scott, J. M. W., 11 Scott, S. K., 1563 Sehested, K., 1101 Seimiya, T., 973 Sellers, R. M., 449 Sermon, P. A., 2577, 2593, 2605 Seyama, H., 485 Sgroi, G., 255 Sharma, R. B., 2627 Shaw, N. K., 343 Shechter, H., 2339 Sherwood, P. M. A., 2745 Shigeto, M., 2941 Shimazu, K., 175 Shirakawa, T., 2835 Shorter, J., 823 Shvets, V. A,, 29 13 Sieber, K. D., 1263 Richoux, M-C., 2461xxxij AUTHOR INDEX Singh, Km. S., 751 Sircar, S., 1527, 1541 Slade, R. C. T., 847 Smith, I. G., 1095 Snelling, C. M., 1761 Sobczyk, L., 311 Siiderberg, D., 17 15 Solar, S., 1101 Solar, W., 1101 Soma, M., 485 Somorjai, G. A., 1263 Somsen, G., 1015 Sorek, Y., 233 Souto, F. A., 2647 Spencer, S., 2357 Spichiger-Ulmann, M., 7 13 Spoto, G., 1283 Spotswood, T. M., 1623 Srivastava, R. D., 913 Stachurski, J., 1447, 2813 Staricco, E. H., 1303 Stock, T., 2257 Stockhausen, M., 397 Stokes, R. H., 1459 Stone, F. S., 1255 Strachan, A. N, 1761 Strohbusch, F., 2021 Stuckless, J. T., 597 Su, Z., 2293 Subrahmanyam, V. S., 1655 Sugimoto, N., 1441, 2959 Suminaka, M., 2287 Suprynowicz, Z., 553 Sutcliffe, L. H., 679, 1467, 1215 Suzanne, J., 2339 Suzuki, H., 3117 Swallow, A. J., 1225 Symons, M. C. R., 433, 565, 727, 2131, 2775, 1095, 1963, 242 1 Takagi, Y., 1901 Takahashi, Y., 3 117 Takeshita, H., 2805 Tamilarasan, R., 2763 Tamura, K., 2287 Tanaka, T., 1513 Taniewska-Osinska, S., 695, Tascon, J. M. D., 939, 2399 Taylor, M. J., 1863 Taylor, N., 2357 Tejuca, L. G., 939, 2399, 1203 Teller, R. G., 1693 Tempere, J-F., 1357 Teramoto, M., 2941 Theocharis, C . R., 857 Thomas, J. K., 735 Tielen, M., 2889, 3049 Tindwa, R. M., 545 Tissier, C., 3081 Toi, K., 2835 Tokuda, T., 2835 Torrez-Mujica, T., 343 Townsend, R. P., 1071, 173 1, Trasatti, S., 2995 Treiner, C., 2513 Trenwith, A. B., 745 Trifiro, F., 1003 Troncoso, G., 1631, 1637 Tseung, A. C. C., 1883 Tuck, J. J., 833 Turner, J. E., 1263 Uemoto, M., 2333 Uma, K., 2733 Valencia, E., 1631. 1637 Valigi, M., 813 Vallmark, T., 1389 Van Oort, M. J. M., 3059 Varma, M. K., 751 Vattis, D., 2043 Vecli, A., 433 Veseli, V., 2095 Vink, H., 1677, 1725 Vliers. D. P., 2009 Vukovid, Z., 1275 3081, 1913 3127 Waghorne, W. E., 2703 Ward, A. J., 2975 Watanabe, H., 1569 Waugh, K. C., 3073 Weckstrorn, K., 2947 Weinberg, N. N., 875 Weingartner, H., 1031 Wells, C. F.. 801, 1057, 1401, White, M. A., 3059 Williams, J. O., 271 1 Williams, P. A., 2635 Williams, P. B., 3067 Williams, R. T., 847 Wojcik, D., 1037 Wood, G. L., 265 Wood, R. M., 273 Woolf, L. A., 769, 2821 Wright, C. J., 2067 Wright, J. P., 1471 Wright, T. H., 1819 Wurie, A. T., 2605 Yadav, G. D., 161 Yadava, R. D., 751 Yamaguchi, M., 1513 Yamaguti, K., 1237 Yamasaki, S., 267 Yamashita, H., 2485 Yamatera, H., 127 Yelon, W., 1693 Yoshida, S., 1513, 2485 Yoshikawa, M., 2485 Zambonin, P. G.. 621 zdanov, S. P., 2541 Zecchina, A., 1283 Zelano, V., 2365 Zhan, R. Y., 2083 Zhao, Z., 185 Zhulin, V. M., 875 Zilnyk, A., 679, 1215 Zulauf, M., 2947 Zundel, G., 1425, 2375 1985. 2145, 2475, 3091

ISSN:0300-9599    

DOI:10.1039/F198581BA001

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

Gas Kinetics Group and Division de Chimie-Physique de la Societe Francaise de Chimie 9th International Symposium on Gas Kinetics To be held in Bordeaux, France on 20-25 July 1986 Further information from Dr R. Lasclaux, Lab. Photophys. Photochim. MolBculaire, Universite de Bordeaux I, 33405 Talence Cedex, France Poiymer Physics Group Biologically Engineered Polymers To be held at Churchill College, Cambridge on 21-23 July 1986 Further information from Dr M. J. Miles, AFRC,Food Research Institute, Colney Lane, Norwich NR4 7UA Polymer Physics Group with the British Rheological Society Deformation in Solid Polymers To be held at the University of Leeds on 9-1 1 September 1986 Further information from Dr J. V. Champion, Department of Physics, City of London Polytechnic, 31 Jewry Street, London EC3N 2EY ~~_____________ ~~~~ Carbon Group Carbon Fibres- P ro pe rt i es and A p p I i cat i o ns To be held at the University of Salford on 1 5 1 7 September 1986 Further information from The Meetings Officer, The Institute of Physics, 47 Belgrave Square, London SW1 X 8QX ~ ~~~~~~~~ ~ Division with the Surface Reactivity and Catalysis Group-Autumn Meeting Promotion in Heterogeneous Catalysis To be held at the University of Bath on 23-25 September 1986 Further information from: Professor F.S. Stone, School of Chemistry, University of Bath, Bath BA2 7AY (viii)Gas Kinetics Group and Division de Chimie-Physique de la Societe Francaise de Chimie 9th International Symposium on Gas Kinetics To be held in Bordeaux, France on 20-25 July 1986 Further information from Dr R.Lasclaux, Lab. Photophys. Photochim. MolBculaire, Universite de Bordeaux I, 33405 Talence Cedex, France Poiymer Physics Group Biologically Engineered Polymers To be held at Churchill College, Cambridge on 21-23 July 1986 Further information from Dr M. J. Miles, AFRC,Food Research Institute, Colney Lane, Norwich NR4 7UA Polymer Physics Group with the British Rheological Society Deformation in Solid Polymers To be held at the University of Leeds on 9-1 1 September 1986 Further information from Dr J. V. Champion, Department of Physics, City of London Polytechnic, 31 Jewry Street, London EC3N 2EY ~~_____________ ~~~~ Carbon Group Carbon Fibres- P ro pe rt i es and A p p I i cat i o ns To be held at the University of Salford on 1 5 1 7 September 1986 Further information from The Meetings Officer, The Institute of Physics, 47 Belgrave Square, London SW1 X 8QX ~ ~~~~~~~~ ~ Division with the Surface Reactivity and Catalysis Group-Autumn Meeting Promotion in Heterogeneous Catalysis To be held at the University of Bath on 23-25 September 1986 Further information from: Professor F. S. Stone, School of Chemistry, University of Bath, Bath BA2 7AY (viii)

ISSN:0300-9599    

DOI:10.1039/F198581FX045

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

xxxij AUTHOR INDEX Singh, Km. S., 751 Sircar, S., 1527, 1541 Slade, R. C. T., 847 Smith, I. G., 1095 Snelling, C. M., 1761 Sobczyk, L., 311 Siiderberg, D., 17 15 Solar, S., 1101 Solar, W., 1101 Soma, M., 485 Somorjai, G. A., 1263 Somsen, G., 1015 Sorek, Y., 233 Souto, F. A., 2647 Spencer, S., 2357 Spichiger-Ulmann, M., 7 13 Spoto, G., 1283 Spotswood, T. M., 1623 Srivastava, R. D., 913 Stachurski, J., 1447, 2813 Staricco, E. H., 1303 Stock, T., 2257 Stockhausen, M., 397 Stokes, R. H., 1459 Stone, F. S., 1255 Strachan, A. N, 1761 Strohbusch, F., 2021 Stuckless, J. T., 597 Su, Z., 2293 Subrahmanyam, V. S., 1655 Sugimoto, N., 1441, 2959 Suminaka, M., 2287 Suprynowicz, Z., 553 Sutcliffe, L. H., 679, 1467, 1215 Suzanne, J., 2339 Suzuki, H., 3117 Swallow, A. J., 1225 Symons, M.C. R., 433, 565, 727, 2131, 2775, 1095, 1963, 242 1 Takagi, Y., 1901 Takahashi, Y., 3 117 Takeshita, H., 2805 Tamilarasan, R., 2763 Tamura, K., 2287 Tanaka, T., 1513 Taniewska-Osinska, S., 695, Tascon, J. M. D., 939, 2399 Taylor, M. J., 1863 Taylor, N., 2357 Tejuca, L. G., 939, 2399, 1203 Teller, R. G., 1693 Tempere, J-F., 1357 Teramoto, M., 2941 Theocharis, C . R., 857 Thomas, J. K., 735 Tielen, M., 2889, 3049 Tindwa, R. M., 545 Tissier, C., 3081 Toi, K., 2835 Tokuda, T., 2835 Torrez-Mujica, T., 343 Townsend, R. P., 1071, 173 1, Trasatti, S., 2995 Treiner, C., 2513 Trenwith, A. B., 745 Trifiro, F., 1003 Troncoso, G., 1631, 1637 Tseung, A. C. C., 1883 Tuck, J. J., 833 Turner, J. E., 1263 Uemoto, M., 2333 Uma, K., 2733 Valencia, E., 1631. 1637 Valigi, M., 813 Vallmark, T., 1389 Van Oort, M.J. M., 3059 Varma, M. K., 751 Vattis, D., 2043 Vecli, A., 433 Veseli, V., 2095 Vink, H., 1677, 1725 Vliers. D. P., 2009 Vukovid, Z., 1275 3081, 1913 3127 Waghorne, W. E., 2703 Ward, A. J., 2975 Watanabe, H., 1569 Waugh, K. C., 3073 Weckstrorn, K., 2947 Weinberg, N. N., 875 Weingartner, H., 1031 Wells, C. F.. 801, 1057, 1401, White, M. A., 3059 Williams, J. O., 271 1 Williams, P. A., 2635 Williams, P. B., 3067 Williams, R. T., 847 Wojcik, D., 1037 Wood, G. L., 265 Wood, R. M., 273 Woolf, L. A., 769, 2821 Wright, C. J., 2067 Wright, J. P., 1471 Wright, T. H., 1819 Wurie, A. T., 2605 Yadav, G. D., 161 Yadava, R. D., 751 Yamaguchi, M., 1513 Yamaguti, K., 1237 Yamasaki, S., 267 Yamashita, H., 2485 Yamatera, H., 127 Yelon, W., 1693 Yoshida, S., 1513, 2485 Yoshikawa, M., 2485 Zambonin, P.G.. 621 zdanov, S. P., 2541 Zecchina, A., 1283 Zelano, V., 2365 Zhan, R. Y., 2083 Zhao, Z., 185 Zhulin, V. M., 875 Zilnyk, A., 679, 1215 Zulauf, M., 2947 Zundel, G., 1425, 2375 1985. 2145, 2475, 3091xxxij AUTHOR INDEX Singh, Km. S., 751 Sircar, S., 1527, 1541 Slade, R. C. T., 847 Smith, I. G., 1095 Snelling, C. M., 1761 Sobczyk, L., 311 Siiderberg, D., 17 15 Solar, S., 1101 Solar, W., 1101 Soma, M., 485 Somorjai, G. A., 1263 Somsen, G., 1015 Sorek, Y., 233 Souto, F. A., 2647 Spencer, S., 2357 Spichiger-Ulmann, M., 7 13 Spoto, G., 1283 Spotswood, T. M., 1623 Srivastava, R. D., 913 Stachurski, J., 1447, 2813 Staricco, E. H., 1303 Stock, T., 2257 Stockhausen, M., 397 Stokes, R. H., 1459 Stone, F. S., 1255 Strachan, A.N, 1761 Strohbusch, F., 2021 Stuckless, J. T., 597 Su, Z., 2293 Subrahmanyam, V. S., 1655 Sugimoto, N., 1441, 2959 Suminaka, M., 2287 Suprynowicz, Z., 553 Sutcliffe, L. H., 679, 1467, 1215 Suzanne, J., 2339 Suzuki, H., 3117 Swallow, A. J., 1225 Symons, M. C. R., 433, 565, 727, 2131, 2775, 1095, 1963, 242 1 Takagi, Y., 1901 Takahashi, Y., 3 117 Takeshita, H., 2805 Tamilarasan, R., 2763 Tamura, K., 2287 Tanaka, T., 1513 Taniewska-Osinska, S., 695, Tascon, J. M. D., 939, 2399 Taylor, M. J., 1863 Taylor, N., 2357 Tejuca, L. G., 939, 2399, 1203 Teller, R. G., 1693 Tempere, J-F., 1357 Teramoto, M., 2941 Theocharis, C . R., 857 Thomas, J. K., 735 Tielen, M., 2889, 3049 Tindwa, R. M., 545 Tissier, C., 3081 Toi, K., 2835 Tokuda, T., 2835 Torrez-Mujica, T., 343 Townsend, R.P., 1071, 173 1, Trasatti, S., 2995 Treiner, C., 2513 Trenwith, A. B., 745 Trifiro, F., 1003 Troncoso, G., 1631, 1637 Tseung, A. C. C., 1883 Tuck, J. J., 833 Turner, J. E., 1263 Uemoto, M., 2333 Uma, K., 2733 Valencia, E., 1631. 1637 Valigi, M., 813 Vallmark, T., 1389 Van Oort, M. J. M., 3059 Varma, M. K., 751 Vattis, D., 2043 Vecli, A., 433 Veseli, V., 2095 Vink, H., 1677, 1725 Vliers. D. P., 2009 Vukovid, Z., 1275 3081, 1913 3127 Waghorne, W. E., 2703 Ward, A. J., 2975 Watanabe, H., 1569 Waugh, K. C., 3073 Weckstrorn, K., 2947 Weinberg, N. N., 875 Weingartner, H., 1031 Wells, C. F.. 801, 1057, 1401, White, M. A., 3059 Williams, J. O., 271 1 Williams, P. A., 2635 Williams, P. B., 3067 Williams, R. T., 847 Wojcik, D., 1037 Wood, G. L., 265 Wood, R. M., 273 Woolf, L. A., 769, 2821 Wright, C. J., 2067 Wright, J. P., 1471 Wright, T. H., 1819 Wurie, A. T., 2605 Yadav, G. D., 161 Yadava, R. D., 751 Yamaguchi, M., 1513 Yamaguti, K., 1237 Yamasaki, S., 267 Yamashita, H., 2485 Yamatera, H., 127 Yelon, W., 1693 Yoshida, S., 1513, 2485 Yoshikawa, M., 2485 Zambonin, P. G.. 621 zdanov, S. P., 2541 Zecchina, A., 1283 Zelano, V., 2365 Zhan, R. Y., 2083 Zhao, Z., 185 Zhulin, V. M., 875 Zilnyk, A., 679, 1215 Zulauf, M., 2947 Zundel, G., 1425, 2375 1985. 2145, 2475, 3091

ISSN:0300-9599    

DOI:10.1039/F198581BX047

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

JOURNAL OF THE CHEMICAL SOCIETY FARADAY TRANSACTIONS, PARTS I A N D 1 1 The Journal of the Chemical Society is published in six sections, of which five are termed Transactions; these are distinguished by their subject matter, as follows: Dalton Transactions (Inorganic Chemistry). All aspects of the chemistry of inorganic and organometallic compounds; including bioinorganic chemistry and solid-state inorganic chemistry; of their structures, properties, and reactions, including kinetics and mechanisms; new or improved experimental techniques and syntheses. Faraday Transactions I (Physical Chemistry). Radiation chemistry, gas-phase kinetics, electrochemistry (other than preparative), surface and interfacial chemistry, heterogeneous catalysis, physical properties of polymers and their solutions, and kinetics of polymerization, etc.Faraday Transactions II (Chemical Physics). Theore tical‘ chemistry , especially valence and quantum theory, statistical mechanics, intermolecular forces, relaxation phenomena, spectroscopic studies (including i.r., e.s.r., n.m.r., and kinetic spec- troscopy, etc.) leading to assignments of quantum states, and fundamental theory. Studies of impurities in solid systems. Perkin Transactions I (Organic Chemistry). All aspects of synthetic and natural product organic, organometallic and bio-organic chemistry, including aliphatic, alicyclic, and aromatic systems (carbocyclic and heterocyclic). Perkin Transactions II (Physical Organic Chemistry). Kinetic and mechanistic studies of organic, organometallic and bio-organic reactions.The description and application of physicochemical, spectroscopic, and theoretical procedures to organic chemistry, including structure-activity relationships. Physical aspects of bio-organic chemistry and of organic compounds, including polymers and biopolymers. Authors are requested to indicate, at the time they submit a typescript, the journal for which it is intended. Should this seem unsuitable, the Editor will inform the author. The sixth section of the Journal of the Chemical Society is Chemical Communications, which is intended as a forum for preliminary accounts of original and significant work, in any area of chemistry that is likely to prove of wide general appeal or exceptional specialist interest. Such preliminary reports should be followed up eventually by full papers in other journals (e.g.the five Transactions) providing detailed accounts of the work. NOTES I t has always been the policy of the Faraday Transactions that brevity should not be a factor influencing acceptability for publication. In addition however to full papers both sections carry at the end of each issue a section headed ‘Notes’, which are short self-contained accounts of experimental observations, results, or theory that will not require enlargement into ‘full’ papers. The Notes section is not used for preliminary communications. The layout of a Note is the same as that of a paper. Short summaries are required. The procedure for submission, administration, refereeing, editing and publication of Notes is the same as for full papers.However, Notes are published more quickly than papers since their brevity facilitates processing at all stages. The Editors endeavour to meet authors’ wishesas to whether an article is a full paper or a Note, but since there is no sharp dividing line between the one and the other, either in terms of length or character of content. the right is retained to transfer overlong Notes to the full papers section. As a guide a Note should not exceed I500 words or word-equivalents. (9NOMENCLATURE AND SYMBOLISM Units and Symbols. The Symbols Committee of The Royal Society, of which The Royal Society of Chemistry is a participating member, has produced a set of recommendations in a pamphlet ‘Quantities, Units, and Symbols’ (1975) (copies of this pamphlet and further details can be obtained from the Manager, Journals, The Royal Society of Chemistry, Burlington House, London W 1 V OBN).These recommendations are applied by The Royal Society of Chemistry in all its publications. Their basis is the ‘Systeme International d’Unites’ (SI). A more detailed treatment of units and symbols with specific application to chemistry is given in the IUPAC Manual of Symbols and Terminology for Physicochemical Quantities and Units (Pergamon, Oxford, 1979). Nomenclature. For many years the Society has actively encouraged the use of standard IUPAC nomenclature and symbolism in its publications as an aid to the accurate and unambiguous communication of chemical information between authors and readers. In order to encourage authors to use IUPAC nomenclature rules when drafting papers, attention is drawn to the following publications in which both the rules themselves and guidance on their use are given: Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F, and H (Pergamon, Oxford, 1979 edn).Nomenclature of Inorganic Chemistry (Butterworths, London, 197 1, now published by Pergamon). Biochemical Nomenclature und Related Documents (The Biochemical Society, London, 1978). A complete listing of all IUPAC nomenclature publications appears in the January issues of .I. Chem. SOC., Faraday Transactions. It is recommended that where there are no IUPAC rules for the naming of particular compounds or authors find difficulty in applying the existing rules, they should seek the advice of the Society’s editorial staff.THE FARADAY DIVISION OF THE ROYAL SOCIETY OF CHEMISTRY Marlow Medal and Prize Applications are invited for the award of the Marlow Medal for 1986 and Prize of f 100. The award will be open to any member of the Faraday Division of the Royal Society of Chemistry who, by the age of 32, had made in the judgement of the Council of the Faraday Division, the most meritorious contribution to physical chemistry or chemical physics. The award will be made on the basis of publications (not necessarily in the Transactions) on any subject normally published in J. Chem. SOC., Faraday Transactions / and //, that carry a date of receipt for publication not later than the candidate’s 32nd birthday. Candidates should be members and under 34 on 1 st January 1986, the closing date for applications, which may be mads either by the candidate himself or on his behalf by another member of the Society.Copies of the rules of the award and application forms may be obtained from: Mrs Y. A. Fish, The Royal Society of Chemistry, Burlington House, London W1V OBN (ii)THE FARADAY DIVISION OF THE ROYAL SOCIETY OF CHEMISTRY SYMPOSIUM NO. 20 Phase Transitions in Adsorbed Layers University of Oxford, 17-1 8 December 1985 Organising Committee : Professor J. S. Rowlinson (Chairman) Dr E. Dickinson Dr R. Evans Mrs Y. A. Fish Dr N. Parsonage Dr D. A. Young The aim of the meeting is to discuss phase transitions at gashquid, liquid/liquid and solid/fluid interfaces, and in other systems of constrained geometry or dimensionality less than three.Emphasis will be placed on molecularly simple systems, whereby liquid crystal interfaces and chemisorption phenomena are excluded. The final programme and application form may be obtained from: Mrs Y. A. Fish, The Royal Society of Chemistry, Burlington House, London W1V OBN THE FARADAY DIVISION OF THE ROYAL SOCIETY OF CHEMISTRY GENERAL DISCUSSION NO. 81 Lipid Vesicles and Membranes Loughborough University of Technology, 15-1 7 April 1986 Organising Committee: Professor D. A. Haydon (Chairman) Professor D. Chapman Mrs Y. A. Fish Dr M. J. Jaycock Dr I. G. Lyle Professor R. H. Ottewill Dr A. L. Smith Dr D. A. Young l h e aim of the meeting is to discuss the physical chemistry of lipid membranes and their interactions, in particular theoretical and spectroscopic studies, polymerised membranes, thermodynamics of bilayers and liposomes, mechanical properties, encapsulation and interaction forces between bilayers leading to fusion but excluding preparation and characterisation methodology.The programme and application form may be obtained from: Mrs Y. A. Fish, The Royal Society of Chemistry, Burlington House, London W1V OBN (iil)THE FARADAY D l V l S l O N OF THE ROYAL SOCIETY OF CHEMISTRY GENERAL DlSCUSSlON NO. 82 Dynam ics of M olecu la r Photof rag mentat ion University of Bristol, 15-1 7 September 1986 Organising Committee: Professor R. N. Dixon (Chairman) Dr G. G. Balint-Kurti Dr M. S. Child Professor R. Donovan Professor J. P. Simons The discussion will focus on the interaction of radiation with small molecules, molecular ions and complexes leading directly or indirectly to their dissociation.Emphasis will be given to contributions which trace the detailed dynamics of the photodissociation process. The aim will be to bring together theory and experiment and thereby stimulate important future work. The preliminary programme may be obtained from : Mrs Y. A. Fish, The Royal Society of Chemistry, Burlington House, London W1V OBN THE FARADAY DIVISION O F THE ROYAL SOCIETY O F CHEMISTRY SYMPOSIUM P rom ot i o n i n H ete rog e neo us Ca t a 1 ys is University of Bath, 23-25 September 1986 Organising Committee : Professor F. S. Stone (Chairman) Dr R. Burch Mrs Y. A. Fish The symposium will form the Faraday Division Programme at the 1986 Autumn meeting of the Royal Society of Chemistry, however, it will be conducted as a discussion meeting, with pre-printed papers and subsequent publication, following the style of the traditional Faraday discussions and symposia.The role of promoters is of intrinsic interest as well as being important for many industrial processes. Promoters are used for three purposes, to improve catalyst activity, to increase selectivity for the desired reaction, and to prolong catalyst life at high activity and selectivity. There are current advances in both exprimental and theoretical aspects of promoter action, making this an opportune time for a Faraday symposium. Attention will be focussed on the role of promoters in enhancing activity and selectivity. Three areas will be highlighted - model studies using well-defined surfaces such as single crystals, characterization of promoter function in real catalysts, and theoretical aspects of promotion.The mechanisms of promoter action in metal, oxide and sulphide catalysts will be discussed. Dr R. W. Joyner Professor J. Pritchard Dr D. A. Young (Editor) Further information may be obtained from: MrsY. A. Fish,The Royal Societyof Chemistry, Burlington House, London WlVOBN.THE FARADAY DIVISION OF THE ROYAL SOCIETY QF CHEMISTRY SYMPOSIUM NO. 21 Interaction-induced Spectra in Dense Fluids and Disordered Solids University of Cambridge, 10-1 1 December 1986 Organking Committee : Professor A. D. Buckingham (Chairman) Dr R. M. Lynden-Bell 13 P. A. Madden Professor E. W. J. Mitchell Dr J. Yarwood Dr D. A. Young Mrs Y.A. Fish Whilst interaction-induced spectra have been studied in the gas phase for many years, their importance in the spectroscopy of condensed matter has been appreciated only relatively recently. At present a considerable number of studies of induced spectra are taking place in what are (nominally) widely separated fields of study. It is highly desirable to bring these communities together so that common issues can be identified and the progress of one field appreciated in another. The preliminary programme may be obtained from : Mrs Y. A. Fish, The Royal Society of Chemistry, Burlington House, London W1V OBN THE FARADAY DIVISION OF THE ROYAL SOCIETY OF CHEMISTRY GENERAL DISCUSSION NO. 83 Brownian Motion University of Cambridge, 7-9 April 1987 Organising Committee Dr M.La1 (Chairman) Dr R. Ball Dr E. Dickinson Dr J. S. Higgins Dr P. N. Pusey Dr D. A. Young Mrs Y. A. Fish The aim of the meeting is to discuss new developments in the experimental and theoretical studies of Brownian motion of colloidal particles and macromolecules, with particular emphasis on the dynamics of aggregate formation and breakdown, computer simulation and many-body hydrodynamic interactions. Contributions for consideration by the Organising Committee are invited and abstracts of about 300 words should be sent by 15 June 1986 to: Dr M. Lal, Unilever Research, Port Sunlight Laboratory, Bebington, Wirral L63 3JW Full papers for publication in the Discussion volume will be required by December 1986JOURNAL OF CHEMICAL RESEARCH Papers dealing with physical chemistry/chemical physics which have appeared recently in J.Chem.Research, The Royal Society of Chemistry’s synopsis+microform journal, include the following: A Partial Determination of the Stability Fields of Ferrierite and Zeolites ZSM-5, ZSM-48, and Nu-10 in the K,O-AI,O,-SO,-NH, [CH,],NH, System Abraham Araya and Barrie M .Lowe (1 985, Issue 6) The Level of Prochirality : the Analogy between Substitutional and Distortional Desymmetrization Amitai E. Halevi (1 985, Issue 6) Radical Cations of Di-, Tri-, and Tetra-bromoethane formed by Radiolysis: an Electron Spin Resonance Study Martyn C. R. Symons (1985, Issue 8) The Use of Deuterium N.m.r. Spectroscopy in Mechanistic Studies of Alkane-exchange Reactions on Supported Platinum and Rhodium Catalysts Ronald Brown, Charles Kemball, James A.Oliver, and Ian H. Sadler (1 985, Issue 9) Electron Spin Resonance Investigation of Environmental Effects in the Photosensitised Reaction of Uranyl Ion with Thioethers Hanna 6. Ambroz and Terence J. Kemp (1 985 Issue 9) The Iron-Vanadium-Oxygen System at 11 23,1273, and 1373 K. Part 2. Activities in Fe,04- FeV,04 Spinel Solid Solutions Larbi Marhabi, Marie-Chantal Trinel-Dufour, and Pierre Perrot (1 985, Issue 1 0) Complexes of Sodium, Potassium, Magnesium, and Calcium Cations with the Lysocellin lonophore in Methanol Jean Juillard, Claude Tissier, and Georges Jeminet (1 985, Issue 10) Is Singlet Cyclopentyne a True Minimum on the C,H, Potential-energy Hypersurface? Santiago Olivella, Miquel A. Pericas, Antoni Riera, and Albert Sole (1985, Issue 10) Clay- and Zeolite-catalysed Cyclic Anhydride Formation Richard W.McCabe, John M . Adams, and Keith Martin (1 985, Issue 11 ) Predicted Binding Energies of Dihydrofolate Reductase Inhibitors Alistair F. Cuth- bertson and W. Graham Richards (1985, Issue 11) FARADAY DIVISION INFORMAL AND GROUP MEETINGS Gas Kinetics Group Reactions without Activation Energies To be held at the University of Birmingham on 10 January 1986 Further information from Professor 1. W. M. Smith, Department of Chemistry, University of Birmingham PO Box 363, Birmingham B1 5 2TT Division-Endo wed Lecture Symposium Perspectives in Colloid Science (including the Liversidge Lecture by R. H. Ottewill) To be held at Imperial College, London on 19 February 1986 Further information from Mrs Y.A. Fish, The Royal Society of Chemistry, Burlington House, London W1 V OBNTheoretical Chemistry Group Post Graduate Students' Meeting To be held at University College, London on 5 March 1986 Further information from Dr G. Doggett, Department of Chemistry, University of York, YorkY01 5DD Molecular Beams Group with CCP6 M o I ec u I a r Scatter i n g-T h eo r y a n d Ex p e r i men t To be held at the University of Sussex on 19-21 March 1986 Further information from Dr A. Stace, School of Molecular Sciences, University of Sussex, Falrner, Brighton BN1 9QJ Division with the Institute of Physics. Institute of Mechanical Engineers, Plastic and Rubber Institute and Institute of Chemical Engineers Tribology in Powder Conveying and Processing: Powder Compaction and Interface Shear To be held at the University of Bradford on 26 March 1986 Further information from Dr B. Briscoe, Department of Chemical Engineering, Imperial College, London SW7 2BY Electrochemistry Group Novel Techniques for the Study of Electrodes and their Reactions To be held at St.Catherine's College, Oxford on 7-9 April 1986 Further information from: Dr S. P. Tyefield, CEGB, Rs Dept, Berkeley Nuclear Laboratories, Berkeley, Gloucestershire GL13 9PB Division-Annual Congress Structure and Reactivity of Gas Phase Ions To be held at the University of Warwick on 8-1 1 April 1986 Further information from: Professor K. R. Jennings, Department of Molecular Sciences, University of Warwick, Coventry CV4 7AL Polymer Physics Group with the Statistical Mechanics and Thermodynamics Group Macromolecular Flexibility and Behaviour in Solution To be held at the University of Bristol on 16-1 8 April 1986 Further information from The Meetings Officer, The Institute of Physics, 47 Belgrave Square, London SWl X 8QX _ _ ___ Division with the Societe Frangaise de Chimie, Deutsche Bunsen Gesellschaft fur Ph ysikalische Chemie and Associazione ltaliana di Chimica Fisica Dynamics of Molecular Crystals To be held at Grenoble, France on 30 June to 4 July 1986 Further information from: Dr C.Troyanowsky, 10 rue Vauquelin, 75005 Paris, France Industrial Physical Chemistry Group Physical Chemistry of Water Soluble Polymers To be held at Girton College, Cambridge on 1-3 July 1986 Further information from Dr I. D. Robb, Unilever Research Laboratory, Port Sunlight, Bebington, Wirral L63 3JW Division with the Institute of Physics, Institute of Mechanical Engineers, Plastic and Rubber Institute and Institute of Chemical Engineers Tribology in Powder Conveying and Processing: Wear Attrition in Powder Flows To be held at the University of Birmingham on 2 July 1986 Further information from Dr B.Briscoe, Department of Chemical Engineering, Imperial College, London SW7 2BY (vii)Gas Kinetics Group and Division de Chimie-Physique de la Societe Francaise de Chimie 9th International Symposium on Gas Kinetics To be held in Bordeaux, France on 20-25 July 1986 Further information from Dr R. Lasclaux, Lab. Photophys. Photochim. MolBculaire, Universite de Bordeaux I, 33405 Talence Cedex, France Poiymer Physics Group Biologically Engineered Polymers To be held at Churchill College, Cambridge on 21-23 July 1986 Further information from Dr M. J. Miles, AFRC,Food Research Institute, Colney Lane, Norwich NR4 7UA Polymer Physics Group with the British Rheological Society Deformation in Solid Polymers To be held at the University of Leeds on 9-1 1 September 1986 Further information from Dr J. V. Champion, Department of Physics, City of London Polytechnic, 31 Jewry Street, London EC3N 2EY ~~_____________ ~~~~ Carbon Group Carbon Fibres- P ro pe rt i es and A p p I i cat i o ns To be held at the University of Salford on 1 5 1 7 September 1986 Further information from The Meetings Officer, The Institute of Physics, 47 Belgrave Square, London SW1 X 8QX ~ ~~~~~~~~ ~ Division with the Surface Reactivity and Catalysis Group-Autumn Meeting Promotion in Heterogeneous Catalysis To be held at the University of Bath on 23-25 September 1986 Further information from: Professor F. S. Stone, School of Chemistry, University of Bath, Bath BA2 7AY (viii)

ISSN:0300-9599    

DOI:10.1039/F198581FP097

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

.I. Chem. SOC., Faraday Trans. I, 1985,81, 2913-2919 On the Nature of the Luminescence Centres on MgO Surface BY VLADISLAV A. SHVETS,* ALEKSEY V. KUZNETSOV, VIKTOR A. FENIN AND VLADIMIR B. KAZANSKY N. D. Zelinsky Institute of Organic Chemistry of Academy of Sciences of the U.S.S.R., Leninsky pr. 47, 117913 Moscow, U.S.S.R. Received 9th July, 1984 The effect of the conditions of the oxygen pretreatment and the adsorption of various molecules on the characteristics of the photoluminescence of thermoevacuated powder MgO have been investigated. The data obtained are shown to be in better agreement with the attribution of the luminescence at 415 nm to surface F l centres and that at 530 nm to surface F: centres, rather than to the coordinatively unsaturated surface 02- anions. Surface defects play an important role as active centres in adsorption and catalysis on magnesium oxide.According to ref. (1)-(5), heating large-surface-area MgO in vacuo at 600-900 "C results in photoluminescence (LM) from the low-coordinated lattice oxygen 02- on the surface. A similar conclusion was also drawn in the case of LM of highly dispersed CaO, SrO and Ba0.3 Investigation of small-surface-area bulk alkaline-earth-metal oxides, including MgO, e.g. single crystals, shows that their LM is caused by defects in the crystalline lattice, namely by F+ and F" centres, i.e. the oxygen vacancies that have captured one or two electrons, respectively.sy The LM of these centres in the bulk of these oxides is due to the photoexcitation and emission of light by these electrons, which have wavefunctions resembling those of the s orbitals of hydrogen but with an expanded Bohr r a d i ~ s .~ Theoretical calculations*, show that the excitation and emission energies of the LM of the surface F,+ centres must be close to the corresponding energies of the bulk F+ centres. In agreement with theory, the excitation energy of the F i centre on the surface of KCl was found to be very close (0.04 eV) to the corresponding bulk va1ue.l" The characteristics of the LM of the bulk F+ centres of the alkaline-earth-metal oxides coincide with those of the surface LM described in ref. (1)-(5). For instance, the LM of the bulk F+ centres in MgO has emission and excitation maxima at 400 and 250 nm, respectively, and the surface LM of MgO, according to ref.(1)-(5), at 400-410 and 250-270 nm. This paper reports a reinvestigation of the LM properties of powdered MgO in order to explore the alternative explanation of the nature of the centres responsible for its appearance. The possibility of the attribution of the LM appearing after thermovacuum treatment of oxides, which do not contain transition- metal ions, to anion-vacancy-type surface defects with captured electrons has been discussed previously for CaOll. l2 and Th02.13 29132914 LUMINESCENCE CENTRES ON MgO SURFACES EXPERIMENTAL The magnesium oxide was prepared by the decomposition of basic carbonate of the 'especially spectrally pure' grade in vacuo at 600 "C for 3 h. For convenience the powder of the starting material was pressed, ground and a fraction of size 0.5-2 mm was selected.Before the experiments the MgO was placed in quartz ampoules, heated in 0, (5-10 kPa, 500 "C, 20-30 min), and thermoevacuated (10-3-10-4 Pa) at a selected temperature in the range 300-1000" for 1-3 h. y-Irradiation of the samples was carried out in quartz ampoules with 6oCo at room temperature. Treatment with CO or 0, to determine the degree of a reduction of the samples was carried out in a circulating system equipped with a liquid-nitrogen trap for freezing of any CO, formed. The amount of CO, was determined by a volumetric method after evacuation of CO or 0, from the system and subsequent warming of the trap up to room temperature . Hydrogen was purified by diffusion through the walls of a hot palladium thimble. Oxygen was liquefied at - 196 "C, one-third of it was then pumped off and the middle fraction was collected.LM spectra were recorded, mainly at room temperature, using MPF-4 Hitachi spectro- fluorimeter. The diffuse reflectance i.r. spectra were recorded at room temperature using a ' Perkin-Elmer 580B ' spectrophotometer provided with a special accessory. RESULTS AND DISCUSSION The LM spectrum of the samples thermoevacuated in the range 300-1000 "C is similar to that observed earlier in ref. (1)-(4). It consists of a wide line with the maximum at 415 nm and a shoulder at 480 nm [fig. 1 (a)] at both 20 and - 196 "C (at the latter temperature the LM is ca. 2.5 times more intense). The excitation spectrum has the maximum at 275 nm [fig. 1 (c)]. We did not observe an increase of the intensity in the excitation spectrum at short wavelengths, this being ascribed in ref.(3) and (5) to the existence of the second excitation maximum at < 230 nm. In our opinion the reason for this spectroscopic difference is poor reproducibility of the shape of the excitation spectrum at the very short wavelengths, as pointed out in ref. (2)-(4). Note that according to ref. (1) the excitation spectrum of MgO does not have any bands at ;1 < 230 nm. With increasing activation temperature up to 1000 "C the intensity of the LM grows, as is shown in fig. 2(a). The form of the spectrum remains unchanged. After heat treatment in CO for the same time as in the case of thermoevacuation and subsequent outgassing for 10 min, MgO samples show LM spectra identical to those shown in fig.1 (a). However, the minimum temperature of treatment required for its appearance is ca. 100 "C lower, and the intensity at each temperature of pretreatment is higher than that after thermoevacuation [fig. 2 (b)]. Moistening the samples before their thermoevacuation also results in higher intensity LM. In the course of the CO treatment the formation of CO, is observed. For example, at a pressure 27 kPa and temperatures of 500 and 700 "C 1.3 x 1019 and 1.9 x 1019 molecule g-l, respectively, is formed. After subsequent treatment at these temperatures more CO, is formed but in smaller quantities (0.3 x 1019 and 0.4 x 1019 molecule g-l at 500 and 700 "C, respectively). These data show that in the CO atmosphere two processes take place: reduction of MgO and disproportion of CO according to the Boudouard reaction into C and CO,.Increasing the temperature of the MgO vacuum treatment up to 1000 "C results in the appearance of new LM with the emission maximum at 530 nm and the excitation maximum at 310 nm (fig. 3). With increasing thermoevacuation time at 1000 "C the intensity of this new LM grows [fig. 2(c)], but the LM at 41 5-480 nm remains almost unchanged [fig. 2 (a)]. The LM in the range 415-480 nm is quenched at 20 "C by 0, (ca. 0.1 kPa). ThisV. A. SHVETS, A. V. KUZNETSOV, V. A. FENIN AND V. B. KAZANSKY 2915 1 LOO 5 00 300 X/nm 200 Fig. 1. LM spectra (Aex = 275 nm) of MgO: (a) thermoevacuated at 800 "C for 1 h, (b) after exposure of (a) to an H,+O, mixture at room temperature and (c) the excitation spectrum of (a) at Aern = 415 nm.1 . o / n e v) +A .r( d m' 0.5 W - 0 . 5 - s '2, 200 LOO 600 800 1000 1000 (4 h) TI°C Fig. 2. Variation of integral intensity of the LM spectra of MgO with temperature of: (a) thermoevacuation (Am = 415 nm, AeX = 275 nm), (b) reduction by CO (Aern = 415 nm, Aex = 275 nm) and (c) thermoevacuation (Aern = 530 nm, Aex = 310 nm). effect is fully reversible, since outgassing of the sample at room temperature restores its initial intensity. The LM at 530 nm is also reversibly quenched by 0, at 20 "C, but it is less sensitive to the oxygen pressure. For example, at 30 kPa its intensity decreases by only a factor of two. Thus the LM at 530nm appearing after the higher-temperature treatment is associated, along with that in the 415-480 nm range, with centres on the surface of MgO since these interact with gaseous oxygen.As already mentioned above, the LM in the range 415-480 nm was previously ascribed to the low-coordinated 0,- ani~ns.l-~ However, the following data allow us2916 LUMINESCENCE CENTRES ON MgO SURFACES to revise this attribution and to ascribe it to surface oxygen vacancies that have captured one electron (FL centres). Moreover, according to these data, LM at 530 nrn should be ascribed to surface anion vacancies with two captured electrons (F," centres). As has been shown above, the reduction of MgO in CO increases the LM intensity at 415-480 nm and shifts the threshold of appearance of the LM toward lower temperatures (fig. 2). These results can be explained by the following scheme of reduction resulting in a formation of oxygen vacancies, 0, which capture electrons: (1) The amount of CO, which is formed at temperatures of 600-800 "C in the course of the reduction shows that the concentration of F,+ centres can reach the value of (1-3) x 1019 g-l when the electrons are not captured by impurities.A similar mechanism is valid for a formation of F,+ centres in the course of the thermoevacuation of MgO: 1 I MgO+xCO -+ MgO,-.,+.xCO,+.uC]+2rre 0 +e -+ F,+. (2) The amount of F,+ centres formed with thermoevacuation is certainly lower than with reduction in CO. Therefore the LM intensity of thermoevacuated samples is lower than that of the reduced ones and appears at higher temperatures. In contrast, reduction by CO should decrease the intensity of LM if it is connected with low-coordinated 0,- anions, because these anions are more reactive than the regular surface 0,-.Heating samples with LM in the range 41 5-480 nm at 550 "C in oxygen (30-40 kPa, 40 min) results in its complete disappearance (the LM spectra were measured after outgassing of 0, at room temperature). At the same time heating of MgO in 0, at higher temperatures (700-800 "C) only decreases the LM intensity without its complete disappearance. Such behaviour should be also explained by the formation of oxygen vacancies according to reaction (2), which is reversible in an oxygen atmosphere. At 500 "C and 30-40 kPa of 0, reaction (2) if likely to be shifted to the left, and at higher temperatures to the right, even at 30-40 kPa of 0,.Thus the disappearance of LM after calcination in oxygen is in agreement with our suggestion about the nature of the emission centres. Moreover, it is not clear why the coordinatively unsaturated 02- ions localized at corners and edges of microcrystals of MgO should disappear after treatment in oxygen. Therefore this phenomenon contradicts the attribution of the LM to low-coordinated 0,- ions. The appearance of the LM at 530 nm after heating MgO in vacuo at 900-1000 "C also substantiates the attribution of both types of LM (at 530 and 415-480 nm) to surface oxygen vacancies that have captured electrons. Indeed, the appearance of this LM is most likely connected with two processes. First, at high temperatures the amount of electrons trapped at anion vacancies increases in accordance with reaction (2).Secondly, simultaneous sintering of the surface takes place leading to a decrease in the concentration of surface oxygen vacancies. Both processes must, apparently, cause an increase in the concentration on the anion vacancies that have captured two electrons, i.e. FZ centres. Consequently, the LM data for MgO heated in vacuo at 900-1000 "C allow the high-temperature LM at 530 nm to be assigned to surface FZ centres and the low-temperature LM in the range 41 5-480 nm to be assigned to surface MgO+Mg0,-z+~0,+xO+2xe n+e+F,+. 2v. A. SHVETS, A . v. KUZNETSOV, v. A. FENIN AND v. B. KAZANSKY 2917 t Xlnm Fig. 3. LM spectra (Aex = 310 nm) of MgO: (a) thermoevacuated at 1000 "C for 1 h, (b) after adsorption on (a) of BC1, at room temperature and (c) the excitation spectrum of (a) at Aem = 530 nm.F: centres. This attribution also agrees with the literature data,14 which show that emission of the bulk F" centres takes place at longer wavelength than that of the bulk F+ centres (530 and 400 nm, respectively). The surface F: centres have strong basic properties, since their EM is not quenched by adsorption of H,O and NH,. At the same time it is fully quenched at room temperature by the adsorption of gaseous Lewis acids such as BCl, [fig. 3(c)]. The LM of F: centres is more easily annealed in 0, than that of F,+ centres. For example, at an 0, pressure. of 10 kPa it begins to decrease at 200 "C and disappears fully following treatment at 400 "C for 10 min. It is well known that F; centres on MgO surface are formed in the course of irradiati~ltl.l~-~~ In this connection we also irradiated the oxidized MgO samples with y-rays at room temperature in ziacuo with a dose of ca.30 Mrad and investigated their photoluminescence. After the irradiation the LM in the range 41 5-480 nm appeared with intensity corresponding to that for the samples thennoevacuated at 500-550 "C. Adsorption of 0, leads to its almost complete quenching. The LM reappears after outgassing of 0, at room temperature with an intensity of CQ. 90% of the initial intensity. Thus the irradiation showed that surface F; centres as well as bulk F;' centres can be luminescent. Moreover, most of them are stable in oxygen at room temperature, although some irreversibly donate electrons to adsorbed oxygen molecules.This leads to the formation of 0; radicals detected by e.p.r.I*, *O We have also observed by e.p.r. the formation of 0; radicals after adsorption of (I2 on the thermoevacuated luminescencing samples of MgO. Their concentration is ca. 10ls g-l, in agreement with ref. (21) and (22). This i s 2-3 orders of magnitude 'less than the concentration of F,t centres determined from the amount of CO,. Thus only a. small part of the thermally induced F$ centres can form 0; radicals. In thermoevacuated samples there is only a weak e.pr. signal assigned to F: This shows that the majority of thermally induced F,' centres are not observed by e.p.r. at 20 and - 196 "C. There are several possible reasons for this, for example F$ centres can be located close to each other and their e.p.r. signal will be broadened by dipole-dipole interaction.However, this problem needs further detailed i 11 vest i g a t i on .2918 3600 LUMINESCENCE CENTRES ON MgO SURFACES 5 % II 3700 fi/cm-' 3800 Fig. 4. 1.r. spectra of MgO: (a) thermoevacuated at 800 "C for 1 h and (b) after exposure of (a) to the H, + 0, mixture at room temperature for 10 min. Note that irradiation-induced bulk and surface F+ centres are annealed at high temperatures: bulk F+ centres disappear near 500 "C in neutron- or electron-irradiated Mg024 and surface F+ centres at 200-300 "C in y-irradiated samples,l5? l6 but in additively coloured crystals annealing takes place at 900-1000 0C.24 The annealing is a result of recombination of electrons of F+ centres with hole centres.In this connection the thermally induced surface F i centres are stable at high temperatures because of the absence of hole centres. The adsorption of H, or 0, at room temperature and their subsequent outgassing for 15-20 min Pa) do not change the LM spectrum of the surface F,S. centres. This is in disagreement with the observation of the influence of hydrogen on the emission spectrum of Mg0.4 In our opinion the difference in the result could be caused by impurities in H, interacting with F,+ centres, for example CO, the adsorption of which strongly affects the LM spectrum of Mg0.25 At the same time exposure of the samples at this temperature to an H, + 0, mixture (6 kPa H,, 1.3 kPa 0,) for 10 min and subsequent evacuation causes the disappearance of the LM band at 4 15 nm, but does not change the shoulder at 480 nm, which is then seen as a clear band [fig.1 (b)]. Simultaneously there is an increase in the intensity of the absorption band at 3626 cm-l in the i.r. spectrum (fig. 4) due to the surface hydrogen-bonded hydroxyl groups.26 The intensity of the band at 3730 cm-1 attributed to the isolated OH groups26 remains unchanged. Note that the interaction of H, + 0, mixture with non-luminescent samples, for example with those oxidized at 550 "C, does not lead to an increase in the bands of both types of hydroxyl groups. The appearance of surface OH groups on MgO after interaction with the H, + 0, mixture and the simultaneous disappearance of the LM at 41 5 nm are also consistent with our suggestion that it is connected with the surface F,S.centres and not with the low-coordinated anions 0,-, because the formation of the surface OH groups takes place only in the presence of oxygen. Apparently, the surface F,+ centres responsible for the LM band at 415 nm react with the H,+O, mixture according to the scheme: 20+2e+0,+H2 -+ 20H;u,,,,,. (3) Consideration of the H,+02 mixture adsorption data shows also that the LM in the range 415-480 nrn comes from the two types of centres with different chemical properties. The LM band at 480 nm may be assigned to F: centres whose structure differs from that of the centres showing luminescence at 410 nm. For example they may be formed on different crystallographic planes. The LM spectra observed in this work allow us to compare the energy parametersv .A. SHVETS, A. v . KUZNETSOV, v. A. FENIN AND v. B. KAZANSKY 2919 of the F," and FZ centres with those characteristic of the corresponding bulk centres. The positions of the maximum in the emission spectra of the bulk and surface F" centres coincide and lie at 530 nm. However, the maximum of the LM excitation of the bulk F" centres lies at 250 nm,14 but that from the corresponding surface defects at 310 nm [fig. 3(b)]. At the same time the maximum of the LM excitation of the F,f centres is observed at 275 nm [fig. 1 (c)] and that of the bulk centres at 250 nm.s, Note that previously27 the FZ centres of MgO were associated with an absorption band at 540 nm, but recently2s it was shown that this band belongs to surface V; centres. CONCLUSIONS The experimental data on the LM of thermoevacuated samples of MgO are in better agreement with the attribution of the LM at 415 nm to the surface FZ centres and that at 530 nm to the Fi centres than to coordinatively unsaturated surface oxygen anions.Of course, it is not necessary to consider these data as a negation of the existence of such anions on the surface of MgO and other oxides. These anions do not luminesce at the excitation with light, but they have absorption bands in the ultraviolet region of the spectrum and have been widely studied by a reflectance spe~troscopy.~~-~~ A. J. Tench and G. T. Pott, Chem. Phys. Lett., 1974,26, 590. S. Coluccia, A. M. Deane and A. J. Tench, Proc. 6th lnt. Congr. Catal. (The Chemical Society, London, 1976), vol. 1, p.171. S. Coluccia, A. M. Deane and A. J. Tench, J. Chem. SOC., Faraday Trans. I , 1978, 74, 2913. S. Coluccia and A. J. Tench, Proc. 7th Int. Congr. Catal. (Kodansha, Tokyo, 1981), p. 1154. S. Coluccia, A. J. Tench and R. L. Segall, J. Chem. Soc., Faraday Trans. I , 1979,75, 1769. B. Henderson and J. E. Wertz, Defects in the Alkaline Earth Oxides (Taylor & Francis, London, 1977), p. 1. A. E. Hughes and B. Henderson, Defects in Crystalline Solidr, ed. J. H. Grawford and L. M. Slifkin (Plenum Press, New York, 1972), vol. 1. R. R. Sharma and A. M. Stoneham, J . Chem. SOC., Faraday Trans. 2, 1976, 72, 913. H. A. Kassim, J. A. D. Matthew and B. Green, Sug. Sci., 1978, 74, 109. J. Eweles and N. Lee, J. Electrochem. SOC., 1953, 100, 399. lo V. M. Bennudez, Surf.Sci., 1978, 74, 568. l2 K. M. Sancier, W. J. Freedericks and H. Wise, J . Chem. Phys., 1962,37, 854. l 3 M. Breysse, B. Claudel, L. Faure and M. J. Guenin, J. Colloid Interface Sci., 1979, 70, 201. l4 B. Henderson and D. C. O'Connell, Semicond. Insul., 1978, 3, 299. l5 R. L. Nelson, A. J. Tench and B. J. Harmsworth, Trans. Faraday SOC., 1967, 63, 1427. R. L. Nelson and J. W. Hale, Discuss. Faraday Soc., 1971, 52, 77. M. Che and A. J. Teneh, Adv. Catal., 1982, 31, 77. I* M. Che and A. J. Tench, Ado. Catal., 1983, 32, 1. lQ J. H. Lunsford and J. P. Jayne, J . Phys. Chem., 1966, 70, 3464. 2o J. H. Lunsford, Catal. Rev., 1973, 8. 135. 21 D. Cordischi, V. Indovina and M. Occhiuzzi, J. Chem. SOC., Faraday Trans. I , 1978,74, 456. 22 D. Cordischi, V. Indovina and M. Occhiuzzi, J . Chem. SOC., Faraday Trans. 1, 1978, 74, 883. 23 J. H. Lunsford and J. P. Jayne, J. Phys. Chem., 1965, 69, 2182. 24 Y. Chen., R. T. Williams and W. A. Sibley, Phys. Rev., 1969, 182, 960. 25 A. V. Kuznetsov, V. A. Shvets, V. A. Fenin and V. B. Kazansky, Kinet. Katal., in press. mi P. J. Anderson, R. F. Horlock and J. F. Oliver, Trans. Faraday Soc., 1965, 61, 2754. 27 R. S. C. Smart, Trans. Faraday Soc., 1971,67, I 183. 28 P. R. Underhiil and T. E. Gallon, Solid. State Commun., 1982, 43, 9. i:Q F. S. Stone and A. Zecchina, Proc. 6th Int. Congr. Catal. (The Chemical Society, London, 1976), 30 A. Zecchina, M. G. Lofthouse and F. S. Stone, J . Chem. Soc., Faraday Trans. I , 1975, 71, 1456. 31 E. Garrone, A. Zecchina and F. S. Stone, Philos. Mag., Sect. B, 1980, 42, 683. vol. 1, p. 162. (PAPER 4/ 1 187)

ISSN:0300-9599    

DOI:10.1039/F19858102913

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

J. Chem. Soc., Faraday Trans. 1, 1985, 81, 2921-2929 Temperature Dependence of the Chemical Potential of Hydrogen in the Two-phase Coexistence Region of the Palladium-Hydrogen System BY TOSHIRO KUJI AND TED B. FLANAGAN* Chemistry Department, University of Vermont, Burlington, Vermont 05405, U.S.A. Received 25th October, 1984 The chemical potential of hydrogen in the coexisting dilute a and hydride a' phases of palladium-hydrogen has been examined as a function of temperature under conditions where there is essentially no hydrogen transferred between the gaseous and solid phases. The behaviour of ApH is governed by the redistribution of hydrogen between the two coexisting phases following the temperature change. If the chemical potentials of the two phases cannot become equal by transfer of hydrogen within the hysteresis gap, then the hydride phase must either form or decompose.This determines whether the system ends up within the hysteresis gap or on one or other of the plateau branches. This model is developed mathematically and confirmed by experimental results for the palladium-hydrogen system. In this contribution we will consider how the chemical potential of hydrogen in a metal-hydrogen system changes when it is cooled or heated within its two(so1id)-phase coexistence region. The limiting situation will be considered where there is no hydrogen transferred between the gas phase and the sample. This limiting situation can be closely approached experimentally by the use of a small dead volume, a large sample and by working in a temperature range where the plateau pressures are small.The interest in the problem arises because of hysteresis. For example, if the metal-hydrogen system is initially on a formation plateaup, at & and the sample is cooled from & to T, because of hysteresis there is the possibility that the system may, at T,, end up on the formation plateau, the decomposition plateau pd or between the two. The problem is of conceptual interest and also of practical interest. For example, with respect to the practical interest, we wished to obtain values of Pd (the decomposition plateau pressure of hydrogen) at low temperatures, < 273 K, for the palladium-hydrogen system. Since the plateau pressures are very small at low temperatures for this system, it is not possible to conveniently withdraw enough hydrogen from the solid to end up on a decomposition plateau.An alternative method for the determination ofp, at low temperatures might be to remove hydrogen at, say, 273 K, where the plateau pressures are appreciable, in order to arrive at Pd (273 K), and then to cool the sample, under conditions that hydrogen transfer from the gas is nil, with the expectation that it will remain on decomposition plateau at the lower temperatures. One purpose of this research is to determine whether this expectation i s correct. 292 12922 CHEMICAL POTENTIAL OF HYDROGEN IN PALLADIUM I 1 I I I 0 0.2 0.4 0.6 H/Pd Fig. 1. Calculated plots of ApH against r for the Pd-H system from results given in ref. (1). Apf, Apd and Apeq refer to the relative chemical potentials of hydrogen for the formation, decomposition and equilibrium plateau, respectively.(i) T = 250 K; (ii) T = 300 K. THEORY OF THE METHOD QUALITATIVE THEORY The following discussion refers to the ideal situation where A(hydrogen/metal) = 0 during heating or cooling, and it also concerns a system with an appreciable hysteresis, e.g. palladium-hydrogen. It seems natural to suppose that if a metal-hydrogen system is on its formation plateau, it should remain on it during cooling, or conversely, if it is on the decomposition plateau, it should remain on it if the sample is heated. For the palladium-hydrogen system this intuitively assumed behaviour can be verified theoretically from the relationships between ApH -+p"H, = RT In (pL2/atm:) and r(H/metal).These are available for this system from the work of Kuji et d.,l who have derived them from the available thermodynamic data. Although these relationships are not exact, they do closely correspond to the actual behaviour and should be able to answer the questions raised above. This analysis is a valid approach for a miscibility-gap system such as palladium- hydrogen or an intermetallic-compound-hydrogen system such as ZrMn2-H.2 In a miscibility-gap system ApH is a continuous function of r. It is further assumed that the coherency stresses are nil, i.e. the phase transition is completely incoherent and (aAp,/ar), can be described at any value of r within the two-phase region by the appropriate combination of the coexisting single-phase values of (dApH/Clr)T.Examples of two such relationships are shown in fig. 1, where the values of Apf, Apd and Apeq are shown; these are the hydrogen chemical potentials for hydrideT. KUJI AND T. B. FLANAGAN 2923 formation, decomposition and equilibrium, respectively ; the last value has been determined from the rule of equal areas. Apf and Apd have been determined from the relationships = + iR In (Pf /Pd)' ( 1 4 and APd = Apeq - $RT In (PflPdY ( W where RTln (Pf/p,)i represents the hysteresis in this system and has been taken from experimental results as 800 J m ~ l - ~ ( H ) . ~ With the aid of fig. 1 various sequences of cooling and heating can be imagined which correspond to possible experimental situations. The following rules, which will be used to derive the final chemical potential of hydrogen resulting from a temperature change, are proposed.(i) When the sample's temperature is changed from T, to q the hydrogen chemical potentials undergo vertical transitions of the coexisting a and a' phases. The pH values of the two phases then attempt to become equal at by transfer of hydrogen from the phase of the higher chemical potential to the phase of lower chemical potential without a phase transformation occurring. If the chemical potentials of the two phases can be equalized in this way, the system will remain in this configuration at q [but see rule (iii)]. (ii) If the p H values cannot become equal by process (i), a hydride phase will either form or decompose in order to allow additional transfer of hydrogen from the phase of the higher chemical potential.In this case the sample must end up on either plateau with the chemical potential A& or Apd at q. (iii) The two phases cannot coexist in a final state with a chemical potential ApH such that ApH < Apd or APE > Apf. It is convenient to definef, andfa. as the fractions of the sample which are in the dilute a and hydride a' phases, respectively. Now consider a sample initially on the Apf at T, (300 K) which is then cooled to T, (250 K). The initial value of fa will determine the outcome of the transition, i.e. the final value of ApH (q). Assume that for this samplef,. <fa and it is at Apf (T,); it is then cooled to & (fig. 1). [It is difficult to indicate the vertical transition T, + q in fig. 1 in the dilute-phase region owing to the steepness of the relationship between ApH and r in this region, but the value of ApH( &) at which the system initially arrives by a vertical transition has been calculated and indicated by the arrowhead 1 in fig.1. The vertical transition q --+ q is indicated in the hydride-phase region.] Now, according to these rules, after the system undergoes the vertical transitions shown, H will be transferred from the a phase to the a' phase, but since fa, <fa, the hydrogen content, r, of the a' phase must change much more than that of the a phase. The hydrogen content of the a' phase increases until it reaches b'(T,) and it must remain at this value because the chemical potentials of the two phases cannot be equalized simply by the transfer of H between phases without violation of rule (iii), and therefore hydride phase must form by the transer of H from the a phase, which ultimately reaches Apf(a',q).It can be seen from fig. 1 that for this system (tlp&/i3ra)T % (Clp$/Clr,f)T, and therefore during cooling from Apf(&) the system will only reach Apf(&) if fa %fa/. Now consider the same transition when f;l# %fa; this leads to a final value of ApH close to end point of the vertical transition occurring in the hydride-phase region, and a phase transition will not occur. Further cooling when fat %fa from & to even lower temperatures will result in the system eventually reaching the Apd plateau. Hence the intuitive assumption that the system will remain on a formation plateau seems to be correct for this system only iff, %fa..starting from Apd(T,), indicated by the arrowhead 2 in the a region. In this case iff, % f a r the chemical potential of the hydride phase will, following the vertical transition, move up to Apf( q), and the hydride phase will form until Ap'&(q) reaches Apf(&). The transition from T, to starting from Now consider a transition from T, to2924 CHEMICAL POTENTIAL OF HYDROGEN IN PAL.LADIUM Table 1. Final plateaux attained following continued heating or cooling starting from the initial plateaux indicated (300 K) heating from the plateau indicated : formation decomposition formation decomposition decomposition formation formation formation decomposition decomposition formation decomposition cooling from the plateau indicated : Apd(&) whenf,, 3- fa is more complex.In this case, following the vertical transition, the chemical potentials cannot become equal by transfer of H from a to d without violating rule (iii). Therefore the a’ phase must decompose, with some of the hydrogen from the decomposition going into the a phase that is formed, but most of it serving to increase the hydrogen content and chemical potential of the remaining a’ phase until it finally arrives at ,ud(b”, TJ. to T2 starting from Apd( q) withf;, B fa., as indicated by the arrowhead 3 in the a-phase. In this case hydrogen transfers from a’ to a until A&(T,) reaches Apd(T2, b”), whereupon the hydride phase decomposes and the H which is transferred to the a phase increases the chemical potential of the a until it reaches Alld(&, a’’).Thus the system will remain on the decomposition plateau. On the other hand, iff,. %fa, the system will end up within the hysteresis gap near the end of the vertical transition shown in the hydride-phase region (fig. 1). Further increases of temperature will result in the sample reaching the Apf plateau. These conclusions are summarized in table 1, where the final terminals are indicated, i.e. the plateau branch which is finally reached after continued cooling or heating. It can be seen from table 1 that there is a symmetry with respect to the expected behaviour for these extreme cases of mostly a or a’ in the sample. Several of these predictions will be tested experimentally using the palladium-hydrogen system. First, however, a quantitative theory will be developed.Now consider heating from QUANTITATIVE THEORY It is assumed in the following that the Av = 0 condition holds for a temperature transition. At equilibrium for a small change of temperature dp,/dT = (a&,/anlZ,) (dng/dT) + (ap&/CT)n73 = (tlp*;r/an$)/(dng/dT) + (ap$/,?T)$H (2) where the A has been omitted in front of the chemical potential of hydrogen for simplicity of representation, and n& and n$ are the amounts (in mol) ef H in the a and a’ phases, respectively. The following equations must hold: dr, = dn&/f, nM and dr,. = dn$/f,. itNI (3) where nM is the number of moles of metal and r, and va/ are the hydrogen/metal ratios in the a and a’ phases, respectively. Because Ar = 0, dng = -dng. Therefore eqn (2) can be rewritten as dpH/d T = m,(dr,/d T) - Sh = m,.(dr,./d T) - S$ (4)T.KUJI AND T. B. FLANAGAN 2925 where ma = (O?p'&/drJT and ma. = (O?p$/tb&. Now dr,/dT = -(&./fa) (dr,./dT) must be evaluated. It is easily shown from the equality on the right-hand-side of eqn (2) that ( 5 ) which can be rearranged to give where A symbols have been added because these are the experimentally measured quantities. Eqn (7) holds only in the case where the chemical potentials can be equalized following a temperature change without a phase transformation, i.e. it is assumed that fa and fa. are fixed. Isothermal changes of ApH upon hydrogen addition or removal from the gas phase within hysteresis gaps have been discussed el~ewhere,~ and this may be helpful background reading for the above together with ref.(4)-(6). It will first be ascertained whether eqn (7) confirms the qualitative predictions of table 1, and then the equation will be employed to make some quantitative comparisons with experiment, For eqn (7) values of AS& and AS$ can be estimated at 300 K, where the phase boundaries are shown in fig. 1, from AS& = As(r, - R In [ r / ( 1 - r)] and AS$ = ASOH - R In [ r / ( 1 - r)] - 4.0 (in J K-l mol-I), in which -4.0 is the excess entropy in this regi0n.l Therefore AS'& = - 18.3 J K-l mol--l (H) and ASg =t - 64.2 J K-l mol-1 (H). Now ma = RT/[a' (1 -a')] = 267.5 kJ mokl (H) and ma. z 24.3 kJ mo1-1 (H), where the latter has been evaluated from fig. 1 and the expression for ma follows from the ideal dilute solubility behaviour in the cc phase.Starting from Apf with (fa/fa.) = 50 we have (dAp,/dT) = 26.6 J K-l mol-1 (H), which leads to A(ApH) = - 1.3 kJ mol-1 kJ mol-1 (H) for the T, -+ q (300 -+ 25@ K) transition. For (fa./fa) = 50 starting from Apf we obtain (dApH/dT) = 64.1 J K-l mol-l (H), which leads to A(ApH) = - 3.2 kJ mol-1 (H) for the T, -+ q transition. Now from fig. 1 it is clear that for the & -+ q change starting from Apf, the following must hold: - 2.64 kJ mol-l (H) 2 A(ApH) 2 - 3.44 kJ mol-1 (H), where the equality signs refer to hydride formation and decomposition, respectively. Therefore for fa/fa' = 50 it is clear that hydride formation must occur; for the case offa,/fa = 50 the sample will end up within the hysteresis gap, but very close to the decomposition branch; a further lowering of temperature will lead to the system ending on Apd.This confirms the qualitative conclusion given in table 1 . It is of interest to examine the same transition when f a =far. = 0.5. For this case (dApH/dT) = 60.3 J K-l mo1-1 (H) and for the transition T, + T,, A(ApH) = - 3.2 kJ mol-l (H), i.e. the result is very similar to the case whenfa./fa = 50. This means that the behaviour is asymmetrical, i.e. the palladium-hydrogen system will not remain o n the hydride formation plateau unless f a 9 fa.. Consider heating the sample from T, to T, starting at Apd(T,) with fa =fa, = 0.5. In this case the quantities in eqn (7) will be evaluated at 250 K where rn, = 692.8 kJ mol--l (H) and ma/ = 20.0 kJ mo1-I (H), AS& = - 10.3 J K-l (H) and AS$ = -66.0 J K-l mol-1 (H).We then obtain dApH/dT = 64.4 J K-l mol-1 (H) or2926 CHEMICAL POTENTIAL OF HYDROGEN IN PALLADIUM -1 .c 3.5 4.0 lo3 K I T Fig. 2. Values of ApH observed for Pd-H during cooling starting from the pd plateau for f , / f , . = 60. (---) calculated behaviour; 0, experimental results. (1 mmHg = 13.5951 x 980.665 x Pa. A(ApH) = 3.22 kJ mol-l (H). It is clear that the sample will nearly move from Apd(G) to the formation plateau after this temperature jump. Other possibilities can be considered, but this should suffice. It can be concluded that the intuitive notion that the system should remain on the formation plateau during cooling or on the decomposition plateau during heating is not generally correct, i.e. these are true only under certain conditions for the palladium-hydrogen system.In experimental situations small amounts of hydrogen will be taken up during cooling or evolved to the gas during heating. If these are very small amounts, the conclusions of eqn (7) will not be markedly altered, but if considerable amounts are transferred, then this must be accounted for. The case of Ar = 0 is closely approached for the palladium-hydrogen system at low temperatures, and this will be used to illustrate these ideas experimentally below. In the next two sections some of the above predictions will be compared with experiment. One practical motive of the present research as mentioned above was the desire to obtain experimental values of pd for the palladium-hydrogen system at low temperatures, where it was not possible to determine these values conveniently owing to the small amounts of hydrogen which could be desorbed from the pf plateau.The sample would remain on the decomposition plateau during cooling only if fa. 9 fa. EXPERIMENTAL A large paladium sample of ca. 15 g was employed in a small dead volume of ca. 45 cm3, which leads to Ar = 1 . 1 x loe4 during cooling from 273 to 200 K if the sample remains on the formation plateau; this is the largest possible change of Ar which can occur during theseT. KUJI AND T. B. FLANAGAN 2927 3.5 4 .O 4.5 103 K I T Fig. 3. Values of ApH observed during cooling starting from the pd plateau forf,,/fm = 2.3. 0, Experimental cooling data; @, data obtained by evacuation under isothermal conditions. experiments and this is insignificant.The sample was generally loaded with hydrogen at 273.2 K to the desired value off,.. If it was desired to be on the decomposition plateau, a hysteresis desorption scan was carried out from the formation to the decomposition plateau at 273.2 K. The kinetics were generally fast even at the lowest temperatures. The pressures were recorded with a series of M.K.S. diaphragm gauges and corrected, where necessary, for thermal transpiration. RESULTS COOLING FROM THE DECOMPOSITION PLATEAU Fig. 2 shows the results of a series of cooling experiments commencing on the decomposition plateau at 273.2 K. For (fa/far) = 60 it can be seen that the sample shifts from the decomposition plateau immediately upon cooling into the hysteresis gap and reaches the formation plateau at ca.248 K. A calculated curve is also shown based on eqn (7) and the evaluation of the appropriate quantities as described above. The calculated values are slightly lower than the experimental ones, but the trend is certainly verified by the calculated results. For (&/fa) = 2.3 it can be seen in fig. 3 that the data follow the decomposition- plateau pressure line to quite low temperatures; this corresponds well with predicted behaviour. This was the method used to determine values of pd down to ca. 230 K. These values correspond well with several values which were measured to ca. 232 K by prolonged evacuation of a sample whilst it was on a plateau until a constant value forp, was obtained (fig. 3). The sample begins to leave the lnp, against T-l line below ca.230 K and enter the hysteresis gap.2928 CHEMICAL POTENTIAL OF HYDROGEN IN PALLADIUM 1.0 L 3.6 3.8 4.0 4.2 4.4 4.6 4.8 lo3 KIT Fig. 4. Values of ApH observed for Pd-H during cooling starting from the pr plateau. e, Data determined withfa/fa, >> 1 ; 0, A, data obtained withfat/f, = 4.6; (---) calculated data forfa,/f, = 4.6. COOLING FROM THE FORMATION PLATEAU Iff, $fa. the system remains on the formation plateau line, and this is how the values of pf have been determined down to 198 K (fig. 4). These values agree well with those directly measured in a series of low-temperature absorption isotherms down to 223 K. Eqn (7) agrees with these experimental results. When (fa./’,) = 4.6 and the sample is cooled, it does not remain on the formation plateau but enters into the hysteresis gap (fig.4). The calculated behaviour agrees well with the experimental results down to ca. 230 K. CONCLUSIONS For the palladium-hydrogen system the conditions under which it remains on a given coexistence plateau when cooling or heating have been established. This is of practical interest because it provides a method of determining values of pf and Pd at low temperatures, where it is experimentally difficult to determine values directly from isotherms, especially the latter values. The results are surprising in that the sample does not remain on the formation plateau during cooling if fat >fa and does not remain on the decomposition plateau during heating iff, > fa.. The behaviour of the chemical potential of hydrogen following these temperature changes within the coexistence region may be understood in terms of the proposed model and the availability of the ApH against r curves for the miscibility-gap system. The results are not generally valid, because each metal-hydrogen system will have a different set of ApH against r relationships; however, this approach will be generally valid for miscibili ty-gap sys tems. We acknowledge the financial support of this research by the N.S.F. (U.S.).T. KUJI AND T. B. FLANAGAN 2929 T. Kuji, W. A. Oates, B. S. Bowerman and T. B. Flanagan, J . Phys. F, 1983, 13, 1783. F. Pourarian, H. Fujii, W. W. Wallace, V. K. Sinha and H. K. Smith, J . Phys. Chem., 1981,89,3105. B. S . Bowerman, G. E. Biehl, C. A. Wulff and T. B. Flanagan, Ber. Bunsenges. Phys. Chem., 1980, 84, 536. D. H. Everett and P. Nordon. Proc. R. SOC. London, A , 1960,259, 341. E. Wicke and G. H. Nernst, Ber. Bunsenges. Phys. Chem., 1964, 68, 224. B. Lambert and S. F. Gates, Proc. R. Soc. London, A , 1925, 108,456. (PAPER 4/1831)

ISSN:0300-9599    

DOI:10.1039/F19858102921

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

J . Chem. SOC., Faraday Trans, I, 1985, 81, 2931-2940 Pore Network Interactions in Ascending Processes Relative to Capillary Condensation BY VICENTE MAYAGOITIA Departamento de Energia, Centro de Investigacih y de Estudios Avanzados del I.P.N., Unidad MCrida, Apartado Postal 73 Cordemex, 97310 MCrida, Yuc. MCxico AND FERNANDO ROJAS AND ISAAC KORNHAUSER* Departamento de Quimica, Universidad Autonoma Metropolitana, Iztapalapa, Apartado Postal 55-534, Mexico 13, D.F. Received 10th December, 1984 It is currently accepted that domain interdependence in adsorption hysteresis (i.e. pore- blocking effects due to hindered liquid-vapour transitions in which the state of any domain depends on those adopted by its neighbours), occurs during the descending (desorption) processes associated with capillary evaporation.In contrast to this behaviour, network effects are thought to be absent during the ascending processes inherent in capillary condensation. However, we have considered the possibility of strong vapour-liquid transitions of an assisted kind taking place during capillary condensation. This situation seems to be the rule, rather than the exception, in a wide variety of porous materials. The interactive effect arises as a consequence of menisci coalescence at the meeting point of capillaries, and it becomes more important as the extent to which the network is filled with capillary condensate increases. When a critical proportion (which depends on the connectivity and geometry of the porous media) of filled elements in the network has been reached, the whole condensation occurs suddenly.This implies that the usual analysis of the ascending boundary curve does not lead to the true pore-size distribution. However, the ascending curve can be predicted from the size distribution and connectivity of the porous network. Much effort has been made to provide an accurate and secure method for the determination of the so-called ‘ pore-size distribution’. Following the analysis of Barrett et aZ.,l one of the most popular techniques consisted of the interpretation involving ‘ adsorption’ and ‘ desorption’ isotherms, normally using nitrogen at its boiling point as the adsorptive. It was customarily preferred to analyse the ‘desorption’ or descending boundary curve of capillary evaporation,2 since true (or more stable) equilibrium, associated with the presence of hemispherical- rather than cylindrical- menisci geometry, is achieved during evaporation.Quinn and McIntosh3 were the first to point out that serious errors in the interpretation of these curves might be committed owing to the presence of an extensive pore-blocking effect in the pourous network. Everett4 and Barker5 have explained the nature of such phenomena: starting from a wholly saturated medium, for a cavity to be able to evaporate its capillary condensate, it is necessary that a continuous path of capillaries that are free of condensate exists from the vapour phase up to that cavity, the nucleation of bubbles being impossible for pores of reduced dimensions. Thus the state (empty or filled with condensate) of a given pore depends on the state of its neighbours.Cranston and Inkley,6 encouraged by results showing some agreement between the cumulative specific surface area obtained from the pore-size distribution curve and the B.E.T.7 293 12932 PORE NETWORK INTEKACTIONS result for this parameter, were the first to suggest that an analysis based on the ‘ adsorption ’ branch, or ascending boundary curve‘ of capillary condensation, would be more appropriate; this could be mainly ascribed to the absence of pore-blocking effects during condensation. Reasons for this absence might be as follows. (a) In each of the empty cavities a vapour-liquid meniscus is present at any moment due to multimolecular adsorption and (b) the fluid can always reach such cavities by successive condensation and re-evaporation, even if condensate surrounds them.Following this line of reasoning, the pore-size distribution ( i e . the volume distribution function in terms of the pore size) may be calculated simply as the derivative of the capillary condensate volume existing in the network, as a function of the size of the pores filled at a particular volume. In fact, strong interactions occur during condensation, as will be shown in this work. These interactions must be taken into account and represent a new difficulty in using the ascending boundary curve to ascertain the true pore-size distribution. First, since any study of the behaviour of fluids on porous materials requires a prior careful description of the porous network itself, we present a discussion of the model used to represent the medium in which the new kind of interaction is envisaged to occur during condensation.This is followed by a study of the evolution of different kinds of menisci which appear during condensation, as well as their mutual interactions. A probabilistic approach then enables us (i) to assess the cooperative phenomena, (ii) to describe the state (full or empty of capillary condensate) of the network elements according to their size and finally (iii) to calculate the ascending boundary curve. MODEL OF THE POROUS NETWORK Before introducing, the particular model of the porous network that will be used in our treatment, several considerations will be made concerning the nature of the elements which constitute the network, their topological disposition, the extent of their interconnections and their size and volume.These general remarks will serve to visualize the span of possible morphologies that our model can represent. A convenient description of the porous network in which capillary processes (such as capillary condensation and evaporation) take place begins with the recognition of two kinds of elements in the network? the sites (or cavities) and the bonds (capillaries and windows). A site is delimited by a certain number of bonds (i.e. a certain number of bonds meet in a site). Every bond is the link between two sites. The connectivity8 is a parameter describing the extent of the interconnections between the elements. Two kinds of connectivities can be defined: the site connectivity, cs (the number of bonds meeting in a site), and the bond connectivity, cB (the number of bonds surrounding a given bond at both ends).The relationship between them is cg = 2(c,- 1). In irregular structures one may obviously expect a different connectivity for each element. However, to avoid an unnecessary degree of complexity in the model, it may be still appropriate to deal with a ‘mean’ connectivity for the whole network. Mayagoitia and Kornhau~er~ have studied the topological characteristics of porous networks constructed from a double (site and bond) distribution of sizes. They obtained probabilistic correlations between the sizes of the elements, and pointed out that the first ‘domain interaction’ to be present in any capillary process is indeed the topological interaction of sizes of the elements in the network itself.Although when there is a certain degree of overlap between the site- and the bond-size distributions, topological correlations are forced to appear, these authors have shown that in theV. MAYAGOITIA, F. ROJAS AND I. KORNHAUSER T-0 T - 0.5 T-1 2933 Fig. 1. Typical examples of porous structures and their corresponding site- and bond-size distributions; each pair of curves shows a certain degree of overlapping ( T ) between them. The shaded area represents the solid phase. In all these examples cs = 4 and cB = 6 (these connectivities are referred only to the plane of the figure). extreme cases where the overlap is either zero or unity, these topological constraints cease to operate.so that it is possible to envisage structures in which the size of the elements is randomly distributed throughout the network. Fig. 1 shows, for several typical cases, the appearance of the networks, together with their corresponding size distribution curves. The size of an element is cumbersome to define, since the element may possess a complicated shape, and several measures of size, in addition to extra qualitative information, should be provided to assess its magnitude. However, the most important measure of an element seems to be during a given capillary process) the mean radius of curvature, R, corresponding to the least-stable meniscus, since this radius governs the passage of fluid to the next element, and/or the filling of the incumbent cavity. We will now introduce the normalized site and bond distribution functions, &(R) and F,(R), on a number-of-elements basis, and the site and bond functions S(R) and B( R) : r R S(R) = Jo &(I?) dR; B(R) = joR F,(R) dR (2) which express the probabilities of finding a site and a bond, respectively, having a size R or smaller.Many difficulties arise when trying to define the volume of the elements. These may depend on the special kind of capillary process taking place within it, and even on the properties of the fluids passing through the element, such as the contact angle, since each element is delimited by least-stable menisci configurations (maxima or minima of menisci curvature). Also, as the volume depends on shape, a unique size parameter may be insufficient to define it.However, it is reasonable to suppose that the larger the cavity, the greater its volume. We will thus assume that the volume of an element, site or bond, depends on its size. A more questionable hypothesis, which nevertheless quite useful, is that there exists a unique function expressing the mean volume, V(R), of all the cavities of size R.2934 PORE NETWORK INTERACTIONS MENISCI CONFIGURATIONS Evereftlo has explained that, in order to reach a full understanding of hysteresis phenomena, it is necessary to undertake two kinds of studies: first, to perform an analysis of the development and stability of menisci formed at individual pores of a given geometry; and second, to carry out a treatment at the level of the whole network. Based on this view, we will deal in this section with menisci, but instead of considering isolated menisci at individual pores, we will be concerned with the behaviour of menisci at the point of meeting of bonds and their interactions.The conclusions to be drawn from this part will be required when treating the network as a whole. It is now necessary to analyse more carefully what is termed the size of an element, R. Since up till now interest in cooperative effects in networks has concentrated on evaporation or descending processes, R has been related to spherical meniscig In capillary condensation, however, the menisci leading to condensation in bonds are ofacylindrical nature, although as will be shown later they are sometimes hemispherical. More generally, the menisci leading to condensation are of an anticlastic nature, since bonds correspond to minima in the cross-section of void space.It is possible to define for them a formal mean radius of curvature, R': where R, and R, are the principal radii of curvature* at the narrowest part of the bond, where the onset of condensation is to be expected. For the sake of simplicity, and in order to avoid extra complications, which may obscure the main goal of this work, it will be considered that IR,I + R,, then we will refer to cylindrical capillaries of radius R = R, having a critical size, in condensation, equal to R' = 2R,. At a certain relative pressure, Pv/Po (being Pv the equilibrium pressure in the vapour phase and Po the saturated vapour pressure), the critical mean radius of curvature, R,, can be expressed in terms of a simplified form of the Kelvin equation:12 R,T In (Po/Pv) = 2ov,/R, (4) where R, is the gas constant, T is the absolute temperature and o and uL are, respectively, the surface tension and the molar volume of the adsorbate.During our treatments, we will maintain the assumption of complete wetting represented by a zero contact angle. A further assumption will be that the thickness of the adsorbed layer is negligible with respect to R,. Individual bonds start filling from the smaller to the larger ones at increasing values of Pv/Po, according to a mechanism similar to that corresponding to cylindrical pores open at both ends, that has been studied both theoretically and experimentally by Everett and Haynes.13 When several bonds which meet at a common site of size R, are filled with condensate, some stages may arise at increasing relative pressures, according to the geometries of the site and bonds.The mechanisms of interaction obey the rule that, in condensation, the mean radius of curvature of the vapour-liquid interface can never be greater than R,. The converse condition leads to an irreversible motion of the interface, according to the Laplace and Kelvin stability analysis of Everett.14 Some of these stages are shown in fig. 2. (a) Menisci do not touch each other, and coalescence between them is impossible under such conditions [fig. 2(a)]. (b) Several menisci just come into contact, but their curvature should decrease if coalescence appears, so the phenomenon does not proceed further [fig.2(b)]. (c) Coalescence takes place, and an * The radius is taken as positive if its centre of curvature lies in the vapour-phase side."V. MAYAGOITIA, F. ROJAS AND I. KORNHAUSER 2935 a C l l b c12 c3 Fig. 2. Several possible configurations adopted by menisci during capillary condensation in connected tunes. Shaded areas represent the solid matrix. In each case the vapour phase is situated on the concave side whilst the liquid phase is on the convex side of the meniscus in question. (-.-. -) Preceding, (-) actual and (----) posterior menisci. advancing meniscus will invade a certain portion of the site. Its motion will continue as long as the radius of curvature remains lower than, or at most equal to, R,. Three possible paths can follow. (c,) If either more than one of the bonds are unfilled [fig.2(c,,)] and/or Rc < Rs [fig. 2 (c12)] the meniscus will lease its motion into the site, leaving the latter filled only to a certain extent. (c,) If all the bonds are filled, and after this, Rc reaches the value R,, condensation takes place in the entire site [fig. 2(c,)]. (c,) if (c, - 1) bonds are filled, arid Rc 2 R,, then an irreversible condensation in the pore and the remaining bond will take place. This is a remarkable situation, and is responsible for aided or assisted interactions occurring during condensation. In this way the former filled bonds cooperate together so as to cause condensation in their previously unfilled first-order neighbours [fig. 2 (c,)]. This interaction is liable to proceed through the whole network, as will be shown in the next section.2936 PORE NETWORK INTERACTIONS CAPILLARY CONDENSATION IN NETWORKS The sizes of sites and bonds will be considered as randomly distributed but still fulfilling the condition9 that B(R) 3 S(R) for every R.( 5 ) A more refined treatment, taking into account the possible size correlations of the elements in the network, can be developed by referring to the study of network hysteresis by Mayagoitia and Kornhau~er.~~ Let us now consider the probability for a certain bond to be free of condensate. The condition for such a bond to be filled on its own (parting from a cylindrical meniscus) is that its size must be smaller than or equal to R,/2. The probability for this event is For a bond to be filled by means of an assisted process at one of its ends, two conditions are required: (a) the site located at that end must have a size R, < R, and (b) the (cs- 1) remaining bonds must already be filled.The probability of fulfilling condition (a) is W,) (7) while that of fulfilling condition (6) is (8) O"s-1 = @Cl3/2 where 0, is the degree of filling of bonds on a number-of-elements basis. Thus the probability of failing to achieve an assisted filling from any of the bond extremities B B is [ 1 - S(R,) 02'71". The probability , I -OB, of the bond of interest to be free of condensate is 1 -OB = [l -B(R,/2)][1 -S(R,)OC,B"]I2. (9) From this expression it is possible to calculate the degree of filling of the bonds as a function of the relative pressure [since S(R,) and B(R,/2) depend on P,/P,].An even more interesting prediction that can also be obtained from the equation above is the ascending boundary curve (i.e. degree of filling, O,, in the volume, as a function Under these circumstances the most tractable situation is that corresponding to the in which the volume of the sites can be neglected compared with the of PVIPO). 'bond' volume of the bonds.* In that case 0, is defined as * The bond model is an extreme example of a porous medium. This model has often been used in the past e.g. by KsensheklR and Everett." In fact, most porous materials may correspond to the site rather than to the bond model. This common situation, related to ink-blot pores, may be present either in a corpuscular state (having well defined solid particles that form the solid matrix) or a spongy state (hollow channels of varying cross-section immersed in a solid phase in which it is impossible to isolate individual entities of the solid).Examples of the former kind are solids obtained from gels, such as silica or alumina, or substances prepared by powder compactation. To the latter group can be assigned Vycor glass, prepared by the leaching of borosilicate glass. Networks relative to the bond model can never be corpuscular, although a corpuscular structure could be a precursor for that kind of network after being subjected to a process of transformation into a spongy system. However, these structures are instead formed by topochemical reactions, as in the case of reduced Fe,O, (by removing Oz), transitional pores in activated carbon (by eliminating combustion products) or paint coatings (by evaporation of the solvent).In spite of the small variety of these kinds of porous structures, their practical importance in fields such as metallurgy, adsorption from the liquid and vapour phases and corrosion, is so important that the present study is not confined to a limited scope.V. MAYAGOITIA, F. ROJAS AND I. KORNHAUSER 2937 Fig. 3. Dashed line shows ascending boundary curve of capillary condensation if interactions were precluded; full lines show real ascending curves according to different values of the bond connectivity as interactions arise: (a) cB = 6, (b) cB = 10, (c) cB = 14. A unique set of size distributions was used for all calculations involved; t h s set consisting of two Gaussian distribution curves with: R, = d2R, = 100 A and oS = oB = 6 8, (K and R, are the means, while os and oB are the standard deviations). where VB(R) is the volume assigned to a bond of size R.Thus to use this equation it is necessary to express the particular degree of filling, OB(R), that bonds of each size possess. From OB(R) in terms of R it is also possible to construct a ‘bond complexion diagram’ as follows. Bonds smaller than R,/2 can be filled on their own: @,(I?) = 1 for R < Rc/2. (12) If the size of the bond lies between Rc/2 and R,, it can be filled by an assisted process, self-filling of the element being impossible. The probability of such a process is simply the sum of the probabilities for the bond to be filled at each extremity: OB is calculated from eqn (10) and still appears in the above expression, owing to the fact that the neighbouring bonds may be of any size.0, is defined by OB = jam @,(R)F,(R)dR. if the bonds are greater than R,, it is impossible to fill them, either by a cylindrical or by a hemispherical meniscus mechanism : OB(R)=O for Rc < R. ( 1 5 ) Finally, the ascending boundary curve is obtained from eqn (1 l), which in turn requires an estimate of @,(I?) derived from eqn ( l o ) , (1 2), (1 3) and (1 5). 96 FAR 12938 t PORE NETWORK INTERACTIONS - R ( a ) Fig. 4. Evolution of the bond complexion diagram as filling of the porous structure oroceeds is shown in (a). The shaded area in (b) represents. at a given relative vapour pressure, the fraction of bonds that are full of condensate, while the blank area corresponds to the empty bonds.The shaded area is, in turn, subdivided in two regions: the one to the right of the broken line comprises those bonds filled by cooperative phenomena, while the one to the left represents the filling expected if no interactions occurred. Calculations for (a) were made on the basis of two Gaussian size distribution curves with R, = 2/2R, = 100 A and os = oB = 6 A. cB was taken equal to 10. DISCUSSION Fig. 3 shows an ideal ascending boundary curve that would be expected if interactions during condensation were absent, together with several real curves, each for a different value of the bond connectivity; all curves correspond to a common set of site- and bond-size distributions. It is evident that connectivity exerts a strong influence upon the outcome of cooperative processes, since the probability for cB/2 filled bonds to occur together at a common site is involved.Similarly, in capillary evaporation a small connectivity leads to acute interactions. An additional parameter greatly influencing the availability of interactions, is the overall probability for coalescence, S(R,) : which relates S(R,) to the coalescence condition expressed in eqn (7). Instead of considering I$(&), it is more appropriate to introduce FB(Rc/2), since the basic mechanism of condensation corresponds to cylindrical menisci. The parameter S(R,) is controlled by the site- and bond-size distributions (i.e. it increases when these distributions approach each other).In contrast to what happens during evaporation, here interactions are enhanced as the size distributions come closer.V. MAYAGOITIA, F. ROJAS AND I. KORNHAUSER 2939 - R Fig. 5. Comparison between the true pore-size distribution (full line), and that to be obtained from experimental data if the usual procedure were followed (dashed line). Calculations _ _ - were performed according to two Gaussian size distribution curves with R, = 2/2 R,, R, = 100 A and os = og = 15 A. cB was taken equal to 10. Thus, a general criterion with regard to interactions occurring during ascending processes would be as follows : f -4 weak or negligible interactions 0.5, moderate interactions + 1, strong interactions accompanied by impending coalescence almost S(Rd = - I everywhere in the network.As illustrated in fig. 3, domain interdependence is more intense the greater the degree of filling. This situation is also found for blocking phenomena in descending processes. la Fig. 4 shows the evolution of the bond complexion diagram as the filling increases. In the absence of assisted processes, the bonds already filled (the left-hand side of the distribution) are separated from those yet to be filled (the right-hand side of the distribution) by a vertical line of height FB(Rc/2). As interactions arise, this line is modified as additional bonds of sizes greater than Rc/2 become part of the filled entities. Fig. 5 shows a true bond-size distribution, as well as the pore-size distribution which would be obtained experimentally, according to the usual procedure (not able to allow for interactions). Here it can be seen that the latter gives rise to an underestimate of pores of larger dimensions.A close resemblance to the pore-blocking behaviour is again seen : the calculated pore-size distributions obtained from experimental evapo- ration curves is also expected to be displaced to the left of the true distribution. CONCLUSIONS A special kind of cooperative effect involved in capillary condensation has been identified and treated by means of a probabilistic approach, and may have serious implications of the pore-size distribution from adsorption data. 96-22940 PORE NETWORK INTERACTIONS Kiselev and Karnaukho~l~ studied the filling of different kinds of cavities in globular (regular) structures. Their findings were as follows.For cavities in arrange- ments with coordination numbers 6 and 8, the filling of the sites is concurrent with the coalescence of menisci at the bonds. Moreover, for tetrahedral cavities (existing in rombohedral packing of coordination number 12) the filling of windows marks the onset of spontaneous filling of the entire site. In these two cases condensation in the site is completely controlled by the sizes of its bonds. Thus the appropriateness of considering cooperative phenomena, which essentially mean that some bonds provoke the filling of certain sites, should not be surprising. This work was supported by the National Council of Science and Technology of Mexico (CONACyT) under grant no. PCCBNAL 790394 (1979). E. P. Barrett, L. G. Joyner and B.P. Halenda, J. Am. Chem. SOC., 1951, 73, 373. D. H. Everett, in The Solid-Gas Interface, ed. E. A. Flood (Marcel Dekker, New York, 1967), vol. 2, p. 1057. H. W. Quinn and R. McIntosh, in Surface Activity, ed. J. H. Schulman (Butterworths, London, 1957), D. H. Everett, Colston Papers, vol. X : Structure and Properties of Porous Materials, ed. D. H. Everett and F. S. Stone (Butterworths, London, 1958), p. 95. J. A. Barker, Colston Papers, 001. X : Structure and Properties of Porous Materials, ed. D. H. Everett and F. S. Stone (Butterworths, London, 1958), p. 125. R. W. Cranston and F. A. Inkley, Adr,. Catal., 1957, 9, 143. 'I S. Brunauer, P. H. Emmett and E. Teller, J. Am. Chem. Soc., 1938, 60, 309. a P. H. Doe and J. M. Haynes, in Characterizution of Porous Solids, ed. S. J. Gregg, K. S. W. Sing and H. F. Stoeckli (SOC. Chem. Ind., London, 1979), p. 253. V. Mayagoitia and I. Kornhauser, RILEMICNR Int. Symp. Principles and Applications of Pore Structural Churacterization, Milan, 1983 (J. W. Arrowsmith, Bristol, 1984), paper 001. vol. 2, p. 122. lo D. H. Everett, Ber. Bunsenges Phys. Chem., 1975, 79, 734. l1 D. H. Everett, in The Solid-Gas Interface, ed. E. A. Flood (Marcel Dekker, New York, 1967), l P W. Thompson, Philos. Mag., 1871, 42, 448. l3 D. H. Everett and J. M. Haynes, J. Colloid Interface Sci., 1972, 38, 125. l4 D. H. Everett, J. Colloid Interface Sci., 1975, 52, 189. l5 V. Mayagoitia and I. Kornhauser, in RILEMICNR Int. Symp. Principles and Applications of Pore l 6 0. S. Ksenshek, Russ. J. Phys. Chem., 1963, 37, 691. l7 D. H. Everett, in The Solid-Gas Interface, ed. E. A. Flood (Marcel Dekker, New York, 1967), p. 1109. l8 D. H. Everett, in The Solid-Gas Interface, ed. E. A. Flood (Marcel Dekker, New York, 1967), l9 A. V. Kiselev and A. P. Karnaukhov, Zh. Fiz. Khim., 1957, 31, 2635. vol. 2, p. 1077. Structural Characterization, Milan, 1983 (J. W. Arrowsmith, Bristol, 1984), paper 002. vol. 2, p.1108. (PAPER 412094)

ISSN:0300-9599    

DOI:10.1039/F19858102931

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

J . Chem. SOC., Furuday Trans. I , 1985,81, 2941-2945 Determination of the Rate of Tautomerization of 1 -Phenylbutane- 1,3-dione (Benzoylacetone) using the Technique of Solubilization into Micelles BY YOSHIKAZU MIYAKA,* MASATO SHICETO~ AND MASAAKI TERAMOTO Department of Industrial Chemistry, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, Japan Received 3rd January, 1985 The distribution constant and the rate of keto-enol tautomerization of 1 -phenylbutane- 1,3-dione (benzoylacetone) have been measured by a new technique using micellar systems in which the dione exists mainly in its enolic form in the micelles. The tautomerization rate was obtained from the absorbance change observed when an aqueous solution of benzoylacetone was mixed with a surfactant solution above the critical micelle concentration, since the tautomerization rate is much slower than the rate of solubilization of the dione into micelles.The tautomerization rate was accelerated by base catalysts such as hydroxide and acetate ions. P-Diketones such as 4,4,4-trifluoro- 1 -(2-thienyl)butane- 1,3-dione (thenoyl trifluoro- acetone) and 1 -phenylbutane-l,3-dione (benzoylacetone, HB) are widely used as chelating agents in analytical and coordination chemistry. Recently some P-diketones have been developed as commercial extractants of copper. It was reported that p-diketones exist as a mixture of keto and enol t a u t o m e r ~ ~ - ~ and that the rate of complex formation of the enolic form of a given P-diketone with a metal ion is much faster than that of the ketonic f ~ r m .~ - ~ Therefore, in order to explain the kinetics of complex formation of a P-diketone with metal ions, it is necessary to determine the fractions of the keto-enol tautomers and the rate of tautomerization. The rates of tautomerization of P-diketones have been measured by several methods such as the field-impulse methodg and the amperometric method.l0 Watarai et ul. determined the rates of the tautomerization of acetylacetone and benzoylace tone by measuring the absorbance change observed when two aqueous solutions with different dielectric constants were mixed.11-13 However, this method cannot be applied to the study of keto-enol tautomerism in aqueous solutions. In this work the distribution of HB between aqueous and micellar phases was measured in micellar systems on the basis of the fact that the enolic form of benzoylacetone is stable in micelle~.~~g l5 The rate of tautomerization of HB in aqueous solution was determined by following the absorbance changes observed when an aqueous solution of HB was mixed with a surfactant solution above the critical micelle concentration (c.m.c.).The rate of tautomerization was also found to be accelerated by base catalysts such as hydroxide or acetate ion. EXPERIMENTAL Benzoylacetone, sodium dodecyl sulphate (SDS) and dodecyl trimethylammonium chloride (DTACl) were purified by recrystallization. t Present address: Showa Denko Co. Ltd, Omarhi, Nagano, Japan. 394 12942 TAUTOMERIZATION RATE OF BENZOYLACETONE To measure the partition coefficient of HB, equal volumes of aqueous solutions of benzoylacetone and the surfactant were mixed and shaken in a water bath kept at 298 K for ca.1 h. The absorption spectra of the solution were measured by a Shimadzu UV-200s spectrophotometer. In the kinetic study two aqueous solutions were rapidly mixed in a chamber using a four-jet mixer and the time courses for the absorption of the solution at both 310 and 250 nm were measured by a rapid reaction analyser of the stopped-flow type (Union Giken Co. Ltd, RA- 1 100). RESULTS AND DISCUSSION SOLUBILIZATION OF HB INTO MICELLES The effect of SDS concentration on the absorption spectra of the mixed solution of HB and SDS was measured.14 The absorption band at 3 10 nm, assigned to the enolic form, increased with an increase in the concentration of SDS, while that at 250 nm, assigned to the ketonic form, decreased.The absorbance of HB in the presence of micelles is expressed as A = dM1) [HB1t/(l = Eobs[HB]t (1) where E and micellar phases, respectively, and a is defined as are the apparent extinction coefficients of HB in the aqueous and PM = [HB],/[HB] = PuM MM] = @MI (2) where [HB], is the concentration of benzoylacetone in the micellar phase based on the micellar volume, P is the normal distribution constant between the two phases, u, is the volume of the micelle, N is Avogadro's number and [MI is the micelle concentration. To estimate the unknown parameters, a and E,, eqn (1) is modified as follows: Here [S], is the total concentration of the surfactant and n is the aggregation number of the micelle.The values of the c.m.c. were determined as the surfactant concentration at which the absorbance at 310 nm began to increase, and were 3.3 mmol dm-3 for SDS and 9.0 mmol dm-3 for DTACl. The values of (a/n) and E~ were estimated from a linear plot l/([S], - c.m.c.) against 1 /(zObs - E ) and are summarized in table 1. The apparent extinction coefficients of HB solubilized in the micellar phase were similar to those obtained in non-polar solvents. This result suggests that the site of the solubilization of HB is inside the micelle, where the polarity is very low. As the fraction of enolic form is > 98% in non-polar s~lvents,l-~ it is deduced that the benzoylacetone solubilized in the micelle exists almost entirely in the enolic form. The value of P was estimated from eqn (2) using the aggregation numbers of the surfactants, i.e.112 for SDS and 50 for DTAC1.l6 The radius of a spherical micelle was assumed to be 2.0 nm for both surfactant~.~~ The values obtained are shown in table 1 with the partition constants of HB between several non-polar solvents and the aqueous phase. The values of P in micellar solutions are similar to those between organic and aqueous phases. /([$h - c*m*c*) = (&M -E)/(Eobs (a/n) - (a/n)- (3) RATE OF TAUTOMERIZATION OF HB When the two solutions of HB and surfactant (above twice the c.m.c.) were mixed, the absorbance at 310 nm increased exponentially with time and that at 250 nm decreased. The relaxation times determined at both wavelengths were the same. The dependences of the observed first-order rate constant (kobs = 7-l) on the concentrations of SDS and DTACl are shown in fig.1 (a) and (b), respectively. The observed rate constant decreased with the increase surfactant concentration.Y. MIYAKE, M. SHIGETO AND M. TERAMOTO 2943 0-06 0-05 0.04 - 'm 0.03- --- 9 Yo 0.02- Table 1. Extinction coefficients of HB in micellar solution and in organic solvents ( E ~ ) at 3 10 nm, a/n, distribution constants between the micellar and aqueous phases and distribution constants between the organic and aqueous phases I I I I I (a 1 - - - - - 0 - Q A surfactant or solvent E~ at 310 nm a/n P (b 1 0.05 - - 0.04 - - 0.03 - - 0.02 - - n SDS 1.26 x 104 120 670 DTACl 1.32 x 104 93 101 DTABr 1.32 x 104 90 CTACl 1.26 x 104 425 101 n-heptane 1.49 x lo4 benzene 1.47 x 104 - 1090 - - - - - water 5.44x 103 f l 0.01 1 0 ' I 1 I I 1 I 0 0-01 0-02 0.03 0.04 0.05 0.06 [ SDS] ,/mol dm -3 I 1 P n v) *O 0-01 t 01 I I 1 I I I I 0 0.01 0.02 0.03 0.04 0.05 0-06 0.07 (DTACl] o/mol dm-3 Fig.1. Effect of micellar concentration on the relaxation rate in micellar solutions of (a) SDS and (b) DTACl. Results were calculated from absorbance at 0, 310 and A, 250 nm, respectively. The pH and the ionic strength of the solutions were adjusted to 4.0 and 0.1 mol dm-3, respectively, with HCl and NaC1.2944 0.05 0.04- Tm 0.03- Ai0 --. YJ n TAUTOMERIZATION RATE OF BENZOYLACETONE! I I I - - n - O 0 - V 0.01 0*02* 2 4 6 0 10 PH Fig. 2. Effect of pH on the relaxation rate. [S], = 15 mmol dmP3 and [HB] = 0.05 mmol dm-3. As the rates of solubilization of organic substances into micelles are very rapid and the rate constants are 100 s-I,17 the process of solubilization relaxation could not be observed in this study.It is considered that the observed relaxation process is attributed to the tautomerization of benzoylacetone in the aqueous phase. The following mechanism is thus proposed : k EM k' H K e H E (HE),. (4) where HK and HE are the ketonic and enolic forms of benzoylacetone, respectively. It is assumed that only the enolic form of HB exists in the micelles, and also that the solubilization process is maintained at equilibrium { P,, = [(HE),]/[HE]). The observed first-order rate constant of relaxation can be expressed as follows : where KT defined by eqn ( 5 ) is the tautomerization equilibrium constant.The solid lines in fig. l ( a ) and (h) are the results calculated from eqn ( 5 ) using the values of a/n in table 1 and a rate constant k = 0.020 s-l, which is very close to the value reported by Harada et ~ 1 . ~ (0.018 s-l). It is concluded that the rate of tautomerization of HB in the aqueous phase can be reasonably explained by chemical relaxation caused by the very fast solubilization of HB into the micelles. The effect of the pH of the aqueous phase on kobs is shown in fig. 2. If the pH of the aqueous solution is comparable to or above the pK, of benzoylacetone, i.e. 8. I, dissociation of HB occurs and the rate of dissociation of the ketonic form is accelerated by hydroxide i ~ n . ~ . ~ ~ The observed rate constant, /cobs, can then be derived as follows : Here Kak is the dissociation constant of the ketonic form and has the value 2.3 x lop9 mol The value of k,, was determined as 2000 dm3 mol-1 s-l from the data shown in fig.2. Eigen et ul. obtained a value of ko, of 4 x lo4 dm3 mol-1 s-l for acetylacetone (pK, = 8.9) by the field-pulse m e t h ~ d . ~ The value for 2- thenoyltrifluoroacetone (pK, = 6.4) was estimated as 130 dm3 rno1-I s-l from the rate of 1 : 1 complex formation between 2-thenoyltrifluoroacetone and NiII or CuT1.18 It is thus deduced that the rate constant decreases with a decrease in pK,.Y. MIYAKE, M. SHIGETO AND M. TERAMOTO 2945 It was also found that the reaction was accelerated by the presence of acetate ion, and the rate constant was correlated as kobs = (0.02 + 0.54[CH,C0,]) [ 1 + 1/( 1 + P E M ) KT].(7) We gratefully acknowledge financial support from a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan. D. J. Sardella, D. H. Heinert and B. L. Shapiro, J . Org. Chem., 1969,34, 2817. T. Shiraiwa and H. Imai, Bunseki Kagaku, 1975, 24, 730. H. Watarai and H. Suzuki, Bull. Chem. SOC. Jpn, 1977, 50, 757. A. V. Cleiano, M. Cefalo and P. S. Gentile, J . Am. Chem. SOC., 1961, 65, 2194. W. K. Ong and H. H. Prince, J. Chem. SOC. A , 1966,458. R. G. Pearson and 0. P. Anderson, Inorg. Chem., 1970, 9, 39. ’ M. R. Jaffe, D. P. Fay, M. Cefalo and N. Sutin, J. Am. Chem. SOC., 1971,93, 2878. M. Harada, M. Mori, M. Adachi and W. Eguchi, J. Chem. Eng. Jpn, 1983, 16, 187. M. Eigen, G. Ilgenfritz and W. Kruse, Chem. Ber., 1965, 98, 1623. lo J. E. Dubois, M. El-Alaoui and J. Toullec, J . Am. Chem. Soc., 1981, 103, 5393. H. Watarai and N. Suzuki, J. Inorg. Nucl. Chem., 1976, 38, 301. l 2 H. Watarai and N. Suzuki, J. Inorg. Nucl. Chem., 1976, 38, 4683. l3 K. Baba, H. Watarai and N. Suzuki, J. Inorg. Nucl. Chem., 1981, 43, 2507. l4 K. Meguro and N. Shoji, in Solution Chemistry of Surfactants, ed. K. L. Mittel (Plenum Press, New l5 T. Suzuki, K. Esumi and K. Meguro, J. Colloid Interface Sci., 1983, 93, 205. I‘ J. D. Bolt and N. J. Turro, J . Phys. Chem., 1981. 85, 4029. I’ H. V. Tartar, J. Phys. Chem., 1955, 59, 1195. York, 1978), vol. 1, p. 407. I. Ando, K. Yoshizumi, K. Ito, K. Ujimoto and M. Kurihara, Bull. Chem. SOC. Jpn, 1983,56, 1368. (PAPER S/034)

ISSN:0300-9599    

DOI:10.1039/F19858102941

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

J . Chem. SOC., Faraday Trans. I , 1985, 81, 2947-2958 Lower Consolute Boundaries of a Poly(oxyethy1ene) Surfactant in Aqueous Solutions of Monovalent Salts BY KRISTIAN WECKSTROM* AND MARTIN ZULAUF European Molecular Biology Laboratory, 156X, 38042 Grenoble Cedex, France Received 8th January, 1985 Lower consolute boundaries up to 50 vol% surfactant have been determined for n- octylpenta(oxyethy1ene glycol) (C,E,) in the presence of the monovalent salts NaF, LiC1, NaCl, KC1, CsCl, NaBr and NaI. We find that the lower consolute boundaries are shifted, with only small changes in shape, to lower or higher temperatures (salting-out or salting-in, depending on the salt used). The amount and sign of the miscibility shift is determined almost solely by the anion, and the shift is related to the surface charge density of the ion.The shifts in the lower consolute boundary cannot be explained by structural changes in the bulk water structure due to the addition of salts. We have applied the Flory-Huggins lattice theory to relate the shifts of the lower consolute boundaries to changes in micelle-solvent interactions. This analysis shows that small changes in the free energy of interaction between oxyethylene and water can explain the shifts in temperature of the lower consolute boundary. We discuss the use and limitations of the Flory-Huggins theory, as applied to micellar phase separation. The salt effects are explained in terms of salt-deficient or salt-rich regions around the oligo-oxyethylene chains. Non-ionic surfactants of the poly(oxyethy1ene) type [CH3(CH,),-,(OCH,CH,),0H, abbreviated as C,E,] exhibit a variety of solution phenomena in water.lt2 When a single homogeneous phase is observed, the surfactant molecules form micellar or mesophase structures with widely different properties.At room temperature the first structured phase is often the micellar phase, which forms above the critical micelle concentration (c.m.c.). At higher concentrations liquid-crystalline mesophases may occur, formed by large anisotropic aggregates arranged in regular array^.^ Depending on temperature and concentration there are solubility limits beyond which phase- separated solutions are found. Upon heating the isotropic micellar solution, a critical temperature is eventually reached at which the solution suddenly becomes turbid ('cloud point).After some time demixing into two transparent liquid phases occurs, one of which contains practically all of the surfactant. The temperature at which the demixing is reached depends on concentration, and the whole boundary is called the lower consolute boundary (1.c.b.). This consolution phenomenon shows features characteristic of transition^^-^ observed with binary liquid mixtures, and it implies that micelles interact attractively to bring about concentration fluctuations preceding the phase separation. The increased interactions, and subsequent demixing, are most probably due to a decrease in the oxyethylene-water interaction, i.e. a decrease in hydration.s Previous neutron-scattering measurements showed that micelles formed by the non-ionic surfactant octylpenta(oxyethy1ene glycol) (C,E,) remain small and approximately spherical, even in the neighbourhood of the demixing b ~ u n d a r y .~ The dehydration of the pentaoxyethylene chains thus has practically no effect on the micellar geometry. Furthermore, the surfactant shows no mesophases above 5 "C and therefore develops a broad micellar It is interesting with this background to 29472948 POLY(OXYETHYLENE) SURFACTANTS study how added inorganic salts change the demixing process. The main effect of the salts is to shift the position of the binary phase boundary in terms of temperature. After presenting the experimental results we discuss ion specificity and apply the Flory-Huggins lattice theory9--13 to analyse the shifts in the lower consolute boundary with temperature.EXPERTMENTAL MATERIALS The non-ionic surfactant C,E,, octylpenta(oxyethy1ene glycol), was used as received from Bachem Feinchemikalien AG (CH-4416 Bubendorf, Switzerland). It has been shown previously that this surfactant is of high purity as judged by elemental composition, thin layer chromato- graphy, infrared spectra and ten3i0rnetry.l~ Also, it is monodisperse with respect to alkyl chain length as well as with respect to its hydrophilic part. No ageing effects were found even after several months' storage in a desiccator at room temperature (cloud points remained unchanged). The salts NaCl, KC1, LiCI, CsCl, NaBr, NaI and NaF were from Fluka AG (puriss) and were used without further purification. The water used was freshly double-distilled.METHODS To determine the clouding temperatures, samples contained in seven quartz cuvettes, (2 x 10 x 40 mm, Hellma) mounted in a Plexiglas box and connected to a thermostat, were observed while slowly raising the temperature (0.1 "C min-' near the critical point) until clouding occurred. The temperature was measured by a platinum resistance thermometer placed in an additional cuvette. Samples were prepared from a stock solution of 50 vol C,E, in water containing various amounts of salt. This solution was allowed to equilibrate overnight. Dilution of the stock solution was then made in order to obtain the final concentrations in quantities of 5@-100 mm3. These were allowed to equilibrate for an additional 2 h before measurement. 'The solutions were prepared with micropipettes on a volume-percent basis, and it was confirmed by weighing that satisfactory accuracy was obtained.Since the density of C,E, is 1.0080 g cm--3 at 20 "C, the weight-percent and volume-percent concentrations are the same within errors of preparation. It was also verified that the measured cloud-point values did not depend on sample volume; volumes of 50, 100, 200 and 400 mm3 gave the same cloud-point values. The readings of cloud-point temperatures obtained by visual inspection were checked by recording absorbance at 450 nm with a spectrophotonieter equipped with a temperature cell and a programmable temperature controller. A temperature increase rate of 20 "C h-l was used. The absorbance showed a clear break at the clouding temperature for C,E, concentra- tions above 0.50/,, and good agreement was found (k0.1 "C) between the two methods and by repeating measurements immediately after clouding.RESULTS It is convenient to represent the different phases formed by non-ionic surfactants in water by temperature uersus concentration diagrams.l The phase diagram of C,E, is then particularly simple7. and comprises three boundary curves distinguishing (i) the monomeric state below the c.m.c. (0.15 7; ), (ii) the hexagonal HI phase extending from 40 to 607; at temperatures below 5 "C and (iii) the two-phase area above ca. 60 "C. In between these boundaries is the ordinary micellar phase. The large area in which the micellar state exists is a typical property of octyloligo-oxyethylenes. Cloud-point temperatures for the surfactants C,E, and C,E, are given in table I .The values for C,E, are shown graphically in fig. I (aj. At concentrations below 0.5:.1,, clouding becomes progressively difficult to observe. We have verified by light scattering that well above the 1.c.b. the aqueous phase obtained after complete phase separation contains micelles at very low concentration. We therefore conclude thatK . WECKSTR~M AND M. ZULAUF 2949 Table 1. Cloud-point temperatures for the non-ionic surfactants C,E, and C,E, in water 0.5 1 .o i .5 2.0 3.0 5.0 10.0 15.0 20.0 25.0 30.0 40.0 50.0 55.0 60.0 65.0 43.4 41.6 40.9 40.3 40.0 39.7 39.7 40.4 41 - 5 43.4 45.6 51.1 57.9 61.1 65.3 69.9 62.6 61.1 60.6 60.2 59.8 59.5 59.4 59.6 60.0 61.1 62.8 66.9 72.8 60 46 0.5 1 5 10 50 0.5 1 5 10 50 Fig.1. Lower consolute boundaries of C,E, in (a) water, (b) 0.5 mol dm-3 NaCl, (c) 0.9 mol dmP3 NaCl and ( d ) 1.3 mol dmP3 NaC1. Points corresponds to the 11 lowest concen- trations in table 1. I 4 2 I922950 POLY (OXYETHYLENE) SURFACTANTS '42 7 0.5 1 5 10 50 ' 4 2 0.5 1 5 10 50 ' 4 2 0.5 1 5 10 50 '9 2 Fig. 2. Lower consolute boundaries of C,E, in (a) 0.2 mol dm-3 NaI, (b) 0.5 mol dm-3 NaI, (c) 0.9 moi dm-3 NaI and ( d ) 1.3 mol dm-3 NaI. the 1.c.b. will rise below 0.5% and merge towards the c.m.c. curve. However, direct observation of clouding by recording optical absorbance (see Experimental section) failed in this concentration region. The neat break in absorbance as a function of temperature found above 0.5% is blurred out below, and we have no direct experimental data on the 1.c.b.there. Note that for surfactants with a short hydrocarbon chain (such as C,E,) the c.m.c. is also less neatly defined than for the longer-chain homologues. We have determined the lower consolute boundary of C,E, in the presence of NaCl, KC1, CsC1, LiC1, NaI, NaBr and NaF. Fig. 1 (b)-(d) shows the 1.c.b. for three NaCl concentrations. The 1.c.b. is shifted to lower temperatures with a small change in curvature of the boundary. Within 0.2-0.4 "C similar 1.c.b. curves are obtained with corresponding molarities of KCl and CsC1. On the other hand, NaI shifts the 1.c.b. to higher temperatures (fig. 2). The salts NaBr and LiCl (fig. 3) are less effective in lowering the boundary position. With NaI, LiCl and NaBr the 1.c.b.is shifted to higher or lower temperatures with practically no changes in the shape of the boundary. Critical concentrations ('4;) for various salt conditions, as obtained from the rectilinear diameter, are given in table 2. The diameter does not show marked deviations from linearity for the salt condition studied, when the surfactant volume fraction is plotted on a logarithmic scale. Shifts in temperature position of the 1.c.b. from the binary value can be interpreted in terms of micellar solubility. As first observed with protein solubility, the effectiveness of salts in reducing solubility followsK. WECKSTROM AND M. ZULAUF 295 1 57 V 2 55 52 u c 50 ‘42 J I I I I 0.5 1 5 10 50 0.5 1 5 10 50 Fig. 3. Lower consolute boundaries of C,E, in (a) 0.5 mol dm-3 NaBr, (b) 1.3 mol dm-3 NaBr, (c) 0.5 mol dm-3 LiCl and (6) 1.3 mol dm-3 LiC1. I 4 2 I41 Table 2.Values of the interaction parameters Hi and Si, their percentage changes, the interaction energy, w, and the critical concentrations, ’4; (in volx), for C,E, c s -Hi - si w ‘4; salt /mol dm-3 /kJ mol-’ AHi PA) /J K-I mo1-1 ASi (%) /J mol-l (~01%) ~~~ NaI 0.5 1.3 NaBr 0.5 1.3 NaCl 0.5 1.3 NaF 0.2 0.5 LiCl 0.5 1.3 12.14 12.51 11.42 11.13 11.06 10.39 11.11 10.48 11.28 10.93 - 4.4 - 7.6 1.8 4.3 4.9 10.7 4.5 9.9 3.0 6.0 40.08 40.61 39.02 38.58 38.47 37.45 38.55 37.58 38.81 38.28 - 1.9 - 192.2 -3.3 -404.2 0.8 21 1.9 1.9 370.7 2.2 407.9 4.8 773.9 2.0 381.8 4.5 722.6 1.3 289.3 2.7 481.3 6.8 8.0 7.0 6.6 8.6 10.2 11.0 15.5 8.2 6.8 - 11.63 - 39.33 - 94.3 8.6 H2O2952 POLY (OXYETHYLENE) SURFACTANTS a certain order, known as the Hofmeister or lyotropic series.16 With CEE5, NaF, LiC1, NaCl, KCl, CsCl and NaBr t,he salt micelles out, whereas salting-in is found with NaI.The salt-induced changes in 1.c.b. shape consist of a progressive deviation from the binary 1.c.b. shape with increasing surfactant concentration. In other words, if the binary 1.c.b. is shifted in temperature by an amount such that it is superimposed on the observed 1.c.b. in the presence of salts at low surfactant concentrations (e.g. 1 vol % ), deviations occur progressively with increasing surfactant concentration (fig. 6). This deviation is - 5.8 "C for C,E, at 50 vol;/i in 1.3 rnol dm-3 NaCl (data not shown). With NaF the deviations are even bigger: - 8.9 "C, at 45 vol % CEE, in a salt solution of 0.5 mol dm-3.The boundaries thus have a flatter shape. Cloud-point temperatures for a 2 vol % CEE, solution as a function of salt molarity are shown in fig. 4. The curves are convex when C,E, is salted out and concave when salting in occurs. Similar salt trends at low surfactant concentration have been reported in several previous studies.,, 1 5 9 17-20 DISCUSSION Recent n.m.r.2y 22 and neutron-scattering m e a s u r e m e n t ~ ~ ~ - ~ ~ provide strong evidence that the consolution phenomenon observed in aqueous solutions of several poly(oxy- ethylene) surfactants (CEE5,C12E,,Cl,~E,Cl,~E) arises from attractive forces between micelles having a fairly constant size. The static and dynamic neutron-scattering results can be accounted for if we assume that micelles remain small, but that they interact according to a direct interparticle potential of the hard-sphere type with an attractive short-range Data analysis on this basis revealed that an increase in temperature corresponds to an increase in the attractive potential depth, with other parameters (micelle size or shape) unchanged.The concentration dependence is thereby reproduced without additional parameter variation. Clouding occurs at a finite value of the attractive potential. The increasing attraction was interpreted as being due to dehydration of the oligo-oxyethylene head groups, allowing closer contacts between micelles to occur upon collisions.26 In fact, both neutr~n-scattering~, and n.m.r. self-diffusion experiments21 indicate a decrease in hydration of the polar layer with increasing temperature.The salts probably change the interparticle interactions, or micelle-solvent interactions, so that the temperature at which phase separation occurs changes. This implies that the salt effects are, to a first approximation, independent of the salt/surfactant molar ratio (fig. 1-3), and that strong ion-micelle interactions are absent. Evidence has been presented before in favour of complex formation between polyvalent ions and lithium with the oligo-oxyethylene parts of non-ionic surfactant~,~~ the ether linkages probably acting as polydentate ligands. Fig. 4 shows that the anions effectively determine the cloud-point temperatures. Cations are known to be smaller and to bind more hydration water than anions.28 Therefore the 1.c.b.shifts are not caused primarily by competition between the ions for free water, but by a more specific anion effect. This becomes evident when the cloud-point temperatures, Td, are plotted as a function of the ionic surface charge density, l/r2 (fig. 5 ) . With chloride as the common anion, Td values do not depend in a marked way on the surface charge density of the cations (crosses in fig. 5). However, we find a regular decrease in Td with decreasing size of the anions when sodium is the common cation. These solubility changes can be further correlated with the structure-breaking ability of the anions. It is well established that structure breaking increases with increasing anionic radius.29 Thus large ions like iodide perturb the tetrahedral hydrogen-bonding pattern of water more than smaller monovalent anions.A comparison between such ionic structure-breaking properties and theK. WECKSTROM AND M. ZULAUF 2953 2 . 3 5 6 I 1 I I I I 0 0.2 0.5 0.9 1.3 C,/mol dm-3 Fig. 4. Cloud-point temperatures of aqueous C,E, solutions (2 vol"/) as a function of salt molarity for the following salts: (1) NaI, (2) NaBr, (3) LiCl, (4) NaC1, ( 5 ) KCL, (6) CsCl and (7) NaF. 7 0 6G LJ iz- 50 40 - 1'- I \ F- 0 .I I 5 r-2 / R -2 Fig. 5. Cloud-point temperatures of aqueous C,E, solutions (2 vol x , 0.5 mol kg-' salt) as a function of r-2, proportional to the surface charge density Z2e2/r2 of either cations (crosses) or anions (circles); 2 is the charge number, e is the electronic charge and Y the crystallographic radius.412954 POLY(OXYETHYLENE) SURFACTANTS observed 1.c.b.shifts shows that structural changes in the solvent cannot solely explain the observations; for example, F- is only a slight structure maker, whereas C1-, Br- and I- are structure breakers.29 This does not correlate with the observed salting-out and salting-in trends. It is also unlikely that the hydration of C,E, increases owing to a partial disruption of the water network, since an increase in temperature lowers the hydration numbers. Which ion actually causes salting-out and which salting-in depends in general on the dielectric and acid-base properties of the With the surfactant C,E, salting-in was observed only with NaI. We will now apply the lattice expression devised independently by Flory and Hugginsg-13 to study how the position with regard to temperature of the lower consolute boundary is related to the free energy of the oligo-oxyethylene-water interaction, and how salts change this interaction.The theory of interacting micelles outlined above predicts (principally correctly) the 1.c.b. shape but with a critical concentration that is too high in comparison with experiment.26 The low critical concentration of the 1.c.b. is most certainly due to the size difference between the micellar aggregates and the solvent water molecules. The Flory-Huggins (FH) theory, originally applied to polymers, takes such size differences into account as a starting principle. Examples of systems where the FH theory has been applied include polymer and non-ionic micellar solution^.^^^ 34 The highly directional interactions occurring when water is the solvent are not explicitly accounted for in the FH theory, which makes its application to aqueous solutions non-rigorous. Alternative theories are in the process of development, but they are not yet easily applicable to the present ~ y s t e m .~ , ? ~ ~ The FH expression for the solvent chemical potential is solutions of where indices 1 and 2 refer to two molecular components, 4 is the volume fraction (b1 + 42 = l), N = V2/ & is the molecular volume ratio of the components, R is the gas constant and w is an interaction energy parameter. The parameter w is a measure of the oligo-oxyethylene-water free energy of intera~ti0n.l~ We use the following (2) expression for co : 1 3 3 33 with the two temperature independent parameters Hi and Si.When applying eqn (1) to the experimental demixing temperatures we make the following assumptions. (1) Previous experimental studies and the results presented here suggest that the phase separation is mediated by oligo-oxyethylene-water interactions. We analyse the salt effects in terms ofchanges in oligo-oxyethylene-solvent (water plus salt) interaction. The two components in the FH equation are thus the oxyethylene of individual micelles and the aqueous solvent. The hydrocarbon regions are not included in the solute volume fraction. Note that the favourable combinatory entropy of mixing arises from the increased volume over which the components are distributed.12 The micellar hydrocarbon forms the aggregate interior and does not mix with the aqueous solvent.Let 0, be the volume fraction of micellized surfactant. Then the volume fraction of rlicellar oligo-oxyethylene is given by CD = Hi - TS, where a is the ratio of the oxyethylene volume to the total surfactant monomer volume. With the specific volumes given in ref. (7) we have a = 0.584 for C,E,. (2) We assumeK. WECKSTROM AND M. ZULAUF 2955 7c 60 V L 1 5c 40 Fig. 6. Fit of the theoretical lower consolute boundaries (see the text) to experimental cloud points of the surfactant C,E, in (a) water, (b) 0.5 rnol dm-3 NaCl and (c) 1.3 mol dm-3 NaCl. that the combinatory entropy of mixing of the micellar oligo-oxyethylene domain can be calculated as for a linear polymer of the same molecular weight, an approximation also used in recent extensions of the FH theory to highly branched (a geometry similar to the micellar oligo-oxyethylene).(3) When phase separation occurs, one of the phases contains surfactant at low concentration. We do not consider the effect of this surfactant on the water chemical potential in the aqueous phase. (4) In the presence of salts the electrolyte contribution to the water chemical potential should be considered. However, we assume that the salt/surfactant molar ratio is the same in both phases, which cancels the salt effect on the chemical potential. Combining eqn ( 1 ) and (2) gives (4) -Hi 4: R[ln (1 - 4 2 ) + (1 - 1/N) 4 2 1 -Si 4: Td = The critical concentration 4; corresponding to the minimum of Td is related to N by13 We then proceed as follows: first the cloud-point temperatures are expressed as a function of headgroup polymer volume fraction using eqn (3).Then eqn (4) is fitted to the experimental data by adjusting the three parameters N, Hi and Si with a least-squares program. The theoretical 1.c.b. for C,E, in water is shown in fig. 6(a). The theoretical boundary deviates slightly, both in form and in the position of the critical point, from the experimental values. This is most probably due to the neglect of terms dependent on solute volume fraction in eqn (3). A more comprehensive analysis of the exact 1.c.b. shape is not pursued here. The following parameter values define the binary 1.c.b.: N = 4520, Hi = - 11.63 kJ mol-1 and Si = -39.33 J K-l mol-l. The error in the Hi and Si values due to the deviation of2956 POI,Y(OXYETHY LENE) SURFACTANTS the theoretical boundary from the experimental values is 15"/<;.The agreement is sufficiently good to study shifts of the boundary with temperature. Eqn ( 5 ) gives a critical concentration of 1.5 vol for the oxyethylene polymer, which is satisfied (a 1 ~ 0 1 % ) by the theoretical boundary (fig. 6). Note that small deviations of the theoretical boundary minima from the condition given by eqn ( 5 ) have been observed before.13 It is not possible in our case to deduce a micellar size from the value of AT, partly because of the approximations mentioned above, but also because the minimum ('4:) in the theoretical 1.c.b. deviates from the experimental minimum [eqn (4)].For C,E, we have7 VEo = 328 A3 and Vw = 30 A3. The definition of N. would give an aggregation number ( u ) of 413, which is roughly five times the aggregation number obtained from neutron-scattering studies' (80 10). For the salt 1.c.b. we fix N = 4520, and thus assume that the micellar size is not affected by added salts. This is supported by the neutron-scattering results for C,E,. which show that the micellar size remains rather constant with increasing temperature, even if the oligo- oxyethylene chains are dehydrated and thus change conformation. It was seen in fig. 1-3 that salts shift the position of the binary 1.c.b. in temperature with only small changes in the boundary shape. We thus retain the binary 1.c.b. shape and explain the observed deviations from this shape by a change in the local salt concentration due to salt-deficient or salt-rich regions around the oxyethylene chains.This implies that the 1.c.b. would be essentially shifted in a parallel manner if the bulk salt concentration was the same as a function of surfactant concentration. The binary 1.c.b. is thus simply shifted in temperature by amounts given by the respective phase separation temperature at low (1 vol ) surfactant concentration. Table 2 summarizes values obtained for Hi and Si for two salt concentrations, together with the respective percentage changes. Also included in the table are values for the interaction parameter cr) at 25 "C. The calculations show that moderate changes in the interaction between the micelles and the aqueous solvent can explain the observed 1.c.b.shifts. Even if the hydrophobic regions do not determine the 1.c.b. shifts they affect the magnitude of Hi and Si. It is thus necessary to study salt effects on particles with hydrocarbon domains of different sizes before a comparison can be made between the absolute values of Hi and Si and experimental quantities. We propose in the following a simple mechanism to account for the observed 1.c.b. shifts. Cations are known to have a strong hydration with a relatively slow exchange of hydration water They are also known to be strongly repelled from a dielectric discontinuity, e.g. from a water/air or water/oil interface, by dielectric image-charge f o r ~ e s . ~ ~ - ~ O Anions show a larger variation, so that the repulsion of the ion decreases in the order F-, C1-, Br- and I-. Iodide can even show a net attraction.This provides an explanation for the strong variation of the salt effect with anion; for example, Aveyard and Heselden have devised a semi-empirical approach for the calculation of salting coefficients which is based on the effect of the electrolyte on the surface tension of the water.42 We propose to discuss the solubility shifts in terms of two separate steps. First is the formation of regions around the oligo-oxyethyleae chains with either lower or higher salt concentration as compared with the bulk. The existence of such regions is entropically unfavourable. This has recently been proposed as the reason for salt-induced miscibility shifts by Garvey and R ~ b b ~ ~ and by Florin et aZ.44 Secondly, the existence of, for example, a salt-deficient region leads to aK.WECKSTROM AND M. ZULAUF 2957 reduction in the oxyethylene-water interaction with increasing salt concentration, in order to satisfy the chemical-potential equilibrium of the water. Fluoride and chloride ions induce the formation of salt-deficient regions around the oligo-oxyethylene chains. The salts NaC1, KCl, CsCl and NaF thus salt-out the surfactant strongly by (mainly) a dehydration mechanism, with characteristic changes in the enthalpic interaction between solute and solvent. These salts also show a marked deviation in 1.c.b. shape from the binary 1.c.b. shape (fig. 6). With NaBr and LiCl the changes in 1.c.b. shape are small, even at 1.3 mol dm-3 salt, which suggests the absence of sai t-deficient regions and renders other mechanisms possible, e.g.these involving the ethylene parts of the molecule. The salt-induced partial-miscibility shifts thus reflect changes in the specific accommodation of the oxyethylene chains in the solvent structure. K.W. acknowledges financial support from the Academy of Finland and thanks Prof. I . Danielsson and Dr D. Worcester for interesting discussions. We also thank iP referee for constructive suggestions. D. J. Mitchell, G. J. T. Tiddy, L. Waring, T. Bostock and M. P. McDonald, J . Chem. Soc., Faraday Trans. I , 1983, 79, 975. C. Tanford, ‘The Hydrophobic EJgect (Wiley, New York, 1980). M. Corti and V. Degiorgio, Opt. Commun., 1975, 14, 358. M. Corti and V. Degiorgso, J. Phys. Chem., 1981, 85, 1442.M. Corti, V. Degiorgio and M. Zulauf, Phys. Rev. Lett., 1982, 48, 1617. T. Nakagawa, in Non-ionic Surfactants, ed. M. J. Schick (Marcel Dekker, New York, 1967), chap. 17. M. L. Huggins, J . Chem. Phys., 1941, 9, 440. lo M. L. Huggins. J . Phys. Chem., 1942, 46, 151. l 1 P. J. Flory, J. Chem. Phys., 1941, 9, 660; 1942, 10, 51. l2 P. J. Flory, 1)iscuss. Furaday Soc., 1970, 49, 7. l 3 P. J. Flory, Principles of Polymer Chemistry (Cornell University Press, Ithaca, New York, 1953). :’ V. Luzzati, W. Mustacchi and A. Skoulios. Discuss. Faraday Soc., 1958, 25, 43. ’ M. Zulauf and J. P. Rosenbusch, J . Phys. Chem., 1983, 87, 856. M. Grabo, Ph.D. Thesis (University of Basel, 1983). L.. Marszall, Tenside Deterg., 1981, 18, 25. l 6 F. Hofmeister, Arch. Exp. Puthol.Pharmakol., 1888, 24, 247. I7 F. Tokiwa and T. Matsumoto, Bull. Chem. Soc. Jpn, 1975,48, 1645. IH M. J. Schick, J . Colloid Sci., 1962, 17. 801. H. Schoit and S . K. Han, J. Pharm. Sci., 1977, 66, 165. ‘Lo 13. Schott, A. E. Royce and S. K. Han, J . Colloid Interface Sci., 1984, 98, 196. 1’. G. Nilsson and B. Lindman, J . Phys. Chem., 1983, 87, 4756. 22 E. J. Staples and G. J. T. Tiddy, J . Chem. Soc., Faraday Trans. I , 1978, 74, 2530. 23 M. Corti, V. Degiorgio, J. B. Hayter and M. Zulauf, Chem. Phys. Lett., 1984, 109, 579. 24 M. Zulauf, K. Weckstrom, J. B. Hayter, V. Degiorgio and M. Corti, in Proc. 5th Int. Symp. Surfactants in Solution, Bordeaux 1984 (Plenum Press, New York, in press). 25 M. Zu!auf, K. Weckstrom, J. B. Hayter, V. Degiorgio and M. Corti, J. Phys. Chem., in press. 26 .I. B. Hayter and M. Zulauf, Colloid Polym. Sci., 1982, 260, 1923. 27 H. Schott. J . Colloid Interface Sci., 1973, 43, 150. p y 13. E. Verrali, in Wuter, A Comprehensive Treatise, ed. F. Franks (Plenum Press, New York, 1973), 3o F. A. Long and W. F. McDevit, Chem. Rett., 1952, 52, 119. 31 R. Koningsveld and L. A. Kleintjens, J. Polym. Sci., Polym. Symp., 1977, 61, 221. 32 R. Kjellander and E. Florin, J . Chem. Soc., Faraday Trans. 1, 1981, 77, 2053. :x3 R. Kjellander, J . Chem. Soc., Faraday Trans. 2, 1982, 78, 2025. 31 J. Goldfarb and L. Sepulveda, J. Colloid Interface Sci., 1969, 31, 454. J. S. Walker and C. A. Vause, J . Chem. Phys., 1983, 79, 2660. ‘j6 c‘. A. Vause and J. S. Walker, Phys. Lett. A , 1982, 90, 419. j 7 L. A. Kleintjens, R. Koningsveld and M. Gordon, Macromolecules, 1980, 13, 303. R8 R. Aveyard and S. M. Saleem, J. Chem. Soc., Faraday Trans. I , 1976, 72, 1609. 0. Ya. Samoilov, Discuss. Faraday Soc., 1957, 24, 141. vol. 3, p. 211.2958 POLY(OXYETHYLENE) SURFACTANTS 39 R. Aveyard, S. M. Saleem and R. Heselden, J . Chem. SOC., Faraday Trans. 1, 1977,73, 84. 40 B. E. Conway, Adv. Colloid Interface Sci., 1977, 8, 91. 41 L. Pauling, The Nature of the Chemical Bond (Cornell University Press, Ithaca, 3rd edn, 1960). 42 R. Aveyard and R. Heselden, J. Chem. SOC., Faraday Trans. 1, 1975,71, 312. 43 M. J. Garvey and I. D. Robb, J . Chem. SOC., Faraday Trans. I , 1979, 75, 993. 44 E. Florin, R. Kjellander and J. C. Ericksson, J. Chem. SOC., Faraday Trans. I , 1984, 80, 2889. (PAPER 5/055)

ISSN:0300-9599    

DOI:10.1039/F19858102947

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

J . Chem. SOC., Faraday Truns. 1, 1985, 81, 2959-2966 Kinetic Hydrogen Isotope Effects in the Reaction between 2,4,6-Trinitrotoluene and 1 -Ethylpiperidhe in Acetonitrile The Effect of Pressure BY NAOKI SUGIMOTO AND MUNEO SASAKI*~ Department of Chemistry, Faculty of Science, Kyoto University, Kyoto 606, Japan Received 14th January, 1985 The effect of pressure on the kinetic isotope ratio kH/kD and tunnelling factor Q has been examined for proton and deuteron transfer from 2,4,6-trinitrotoluene (TNT) to 1-ethylpiperidine in acetonitrile. The reaction rate has been measured in the pressure range 1-1000 bar and in the temperature range 15-35 "C by means of a high-pressure stopped-flow method. Even at 1000 bar, the kinetic isotope ratio kH/kD (16.4), the activation energy difference E,(D) - E,(H) (10.0 kJ mol-l) and the ratio of Arrhenius pre-exponential factor A(D)/A(H) (4.0) are large, suggesting a considerable tunnelling contribution. However, the tunnelling factor Q(H), calculated according to Bell's equation, hardly changes with pressure (being 2.39 at 1 bar and 2.26 at 1000 bar).Tunnelling phenomena and related pressure effects are discussed in relation to the curvature of potential-energy barriers. The present results lead us to conclude that large changes of kH/kD with pressure do not always confirm the occurrence of tunnelling. Several authors have reported large kinetic isotope effects kH/kD resulting from the effect of pressure on proton tunnelling rea~tions.l-~ Since the report' that kH/kD for the reaction of leucocrystal violet with chloranil decreases from 11 at 1 bar to 8 at 2 kbar it has been assumed that increasing pressure reduces the degree of tunnelling and that reactions where kH/kD is independent of pressure do not involve tunnelling.However, it was shown that kH/kD for the reaction between 2,6-di-t-butylphenol and 1,l -diphenyi-2-picrylhydrazyl (DPPH) did not vary with pressure, though it was as large as 18 at 1 bar.2 We have also shown that the change of kH/kD with pressure for the reaction between 4-nitrophenylnitromethane (NPNM) and tetramethylguani- dine (TMG), which might undergo tunnelling,* is solvent-de~endent.~ We have studied effects of solvent and pressure on proton tunnelling in the reaction of 2,4,6-trinitrotoluene with several base^.^-^ We also examined quantitatively the effect of pressure on the barrier dimensions and degree of tunnelling in the reaction between TNT and 1,8-diazabicyclo[5.4.O]undec-7-ene (DBU) in acetonitrile.6. We found that the curvature v of the barrier becomes much smaller with increasing pressure, suggesting that the tunnelling degree Q decreases.' In this paper we deal with the proton and deuteron transfers, in which tunnelling is expected,1° from TNT to 1-ethylpiperidine (EP) in acetonitrile in order to examine the effect of pressure on the barrier dimensions and tunnelling in this system.We will discuss the pressure effect on tunnelling by considering the two factors v and (3 In v/@),, and show that the latter is important as well as the magnitude of v itself. t Present address: Department of Chemistry, Faculty of Science, Konan University, Kobe 658, Japan.29592960 KlNETIC ISOTOPE EFFECTS EXPERIMENTAL MATERIALS TNT and deuterated 2,4,6-trinitrotol~ene([~H,ITNT) were treated as described previou~ly.~~ 1-Ethylpiperidine (Nakarai Chemical Co. Ltd) was dried with potassium hydroxide and then distilled several times before use. Acetonitrile was purified by the standard method' and all solutions were freshly prepared immediately before use. APPARATUS AND PROCEDURES Absorption spectra were recorded using a Shimadzu UV-200s spectrophotometer. Kinetic measurements at 1 bar were carried out using a Union Giken RA-401 stopped-flow apparatus. At pressures of 500 and 1000 bar the reaction rate was followed using our high-pressure stopped-flow apparatus.I1 The temperature range was 15-35 "C for proton transfer and 15-30 "C for deuteron transfer, and the temperature was regulated within kO.1 "C by circulating thermostatted fluid. The following concentrations of solutions were used in the kinetic measurements: TNT,[2H,]TNT, 0 .1 4 4 mmol dmp3; EP, 3-64 mmol dmp3. The reaction rate was determined according to the same procedure as before." 9* lo RESULTS Plots of the observed first-order rate constant kobs against the base concentration [B] were linear (fig. 1 and 2) in agreement with the equation where k,L and kk are the forward and backward rate constants of the proton- and deuteron-transfer reactions ( L = H or D), respectively. The base concentration at each pressure is expressed in terms of molarity in order to enable comparison of the rate constants with those of other reactions.Tables 1 and 2 list the values of k,H, k f and k,D at each temperature and pressure. The values of k: were too small and not sufficiently accurate to justify their use in deriving activation parameters or kinetic isotope effects; e.g. k: was 0.060 s-l at 1 bar, and 0.075 s-l at 1000 bar (both at 25 "C). The activation parameters at 1, 500 and 1000 bar were computed by a least-squares method (tables 3 and 4) from the temperature dependence of the rate constants. An activation volume AV$(L) for the forward reaction at each temperature was determined from the linear plots of Ink against p based on the equation RT(hk,L/ap), = -AV$(L)-lcRT (2) where K is the compressibility of the solvent, which can be obtained from literature.12 The values of AV$(H) and AVT(D) are shown in table 5 together with those of k,H/k,D.The tunnelling factor Q and curvature v of an unsymmetrical parabolic potential barrier were computed on the basis of Bell's equation [eqn (3)],13 and the resulting values are shown in table 6: OL' Q = O.Su/sin ( 0 . 5 ~ ) - (- exp [(u - 2nn) cc/u]/[(u- 2nn)/u] (3) n-1 where and a = E/kT, u = hv/kT (4)N. SUGIMOTO AND M. SASAKI 296 1 6 - 4 L I Xg Y 2 0 20 40 60 [B]/mmol dmP3 Fig. 1. Dependence of k z s on EP concentration for the TNTfEP reaction in acetonitrile: 1 bar, 15 "C (a); 1000 bar, 15 "C (0); 1 bar, 25 "C (A); 1000 bar, 25 "C (A); 1 bar, 35 "C (0); 1000 bar, 35 "C (0). 1 I I I 1 I I 0 20 40 60 [B]/mmol dm-3 Fig. 2. Dependence of k& on EP concentration for the [2H,]TNT + EP reaction in acetonitrile: 1 bar, 20 "C (A); 1000 bar, 20 "C (A); 1 bar, 30 "C (a); 1000 bar, 30 "C (0).2962 KINETIC ISOTOPE EFFECTS Table 1.Rate constants k,H and kf for the forward and backward proton-transfer reactions T/"C ~ ~~~~ 15 20 25a 30 35 p = 1 bar k,H/dm3 mol-l s-l 19.2k0.4 25.4f0.8 39.2k0.4 51.4k 1.5 68.7+ 1.4 kF1s-l 0.52+0.01 0.74f0.02 0.95k0.01 1.23f0.04 1.63f0.03 p = 500 bar k,H/dm3 mo1-ls-l 20.9k0.5 27.7k0.7 43.2+ 1.0 57.0f 1.1 76.3k2.2 k?/s-' 0.57 & 0.01 0.76 + 0.02 1.05 k 0.03 1.28 f0.03 1.70 k 0.05 p = 1000 bar kF/dm3 mol-1 s-l 22.7 k 0.5 30.2 k 0.9 47.0 k 0.9 62.2 k 1.8 83.9 k 1.7 k,H/s-l 0.60k0.01 0.88f0.03 1.14k0.02 1.30f0.04 1.88k0.04 a KH=(kfH/kf)=41.3+0.9,41.1+2.1 and41.2f1.5dm3rnol-l,at 1, 500and lOOObar, respectively.Table 2. Rate constants k,D (dm3 mol-l s-l) for the forward deuteron-transfer reaction T/"C p/bar 15 20 25a 30 1 1.04k0.03 1.47k0.06 2.32f0.05 3.43f0.14 500 1.18k0.06 1.65k0.09 2.62f0.08 3.87k0.12 1000 1.27k0.08 1.81 k0.08 2.87f0.10 4.26k0.21 a KD = (kfD/kF) z 39, 38 and 38 dm3 mol-' at 1, 500 and 1000 bar, respectively. Table 3. Activation parameters of the forward and backward proton-transfer reactions at 25 "Cd 1 500 1000 AHi(H)/kJ mo1-I 45.6 k0.8 46.4 f 1.3 46.9 f 1.3 AG!(H)/kJ mol-l 64.0+ 1.3 64.0 f 1.7 63.6 k 1.7 Er(H)/kJ mol-l 48.1 f 0.8 49.0 f 1.3 49.4 & 1.3 lO.OfO.1 10.2 f 0.1 10.3 f 0.1 AHi(H)/kJ mol-l 38.9 k 0.4 37.7 40.8 36.8 & 0.8 AGb(H)/rnol-' P 73.2 k0.8 72.8 + 1.7 72.8 f 1.7 E$(H)/kJ mol-l 41.4 f 0.4 40.2 & 0.8 39.3 f 0.8 7.2 f 0.1 7.0f0.1 7.0 f 0.1 ASt(H)/J K-l mol-l -61.9+ 1.3 -58.2k 1.7 -56.5_+ 1.7 log A m AS$(H)/J K-l mol-' - 115.0f 1.3 - 119.0k2.5 - 120.0k2.9 log a AHo = (AH!-AH:) = 6.7, 8.7 and 10.1 kJ mol-l at 1, 500 and 1000 bar, respectively.N .SUGIMOTO AND M. SASAKI 2963 Table 4. Activation parameters of the forward deuteron-transfer reaction at 25 "C 1 500 1000 ~~ ~~~~~ AHi(D)/kJ mol-' 56.1 k0.8 56.1 & 1.2 56.9+ 1.2 AGf(D)/kJ mol-' 71.1 & 1.2 70.7+ 1.7 70.3f 1.7 E;(D)/kJ mol-l 58.6 k 0.8 58.6 f 1.2 59.45 1.2 log A m 10.6k0.1 10.7 0.1 10.9 f 0.1 16.9k0.5 16.5 5 0.9 16.4 f. 0.9 9.6 & 2.5 10.0f2.5 E:(D)-Er(H)/kJ mol-' 10.5f. 1.6 A,(D)/A,(H) 4.0 f 1.6 3.2 a 1.6 4 . w .6 ASt(D)/J K-l mol-l -49.8f0.8 -49.4f 1.2 -45.250.8 kP/kf Table 5.Kinetic isotope rate ratios k,H/k,D and activation volumes A V: T/"C p/bar 15 20 25 30 1 500 1000 18.5 k0.9 17.3 1.3 16.9 f 0.5 15.0+ 1.0 17.7k 1.3 16.8k 1.3 16.5 5 0.9 14.7 f- 0.7 17.9f 1.5 16.7 1.2 16.4 f 0.9 14.6 f 0.9 A Vl(H)/cm3 mol-' - 6.5 f 0.4 - 7.0 f 0.4 - 7.2 f0.5 - 7.7 f. 0.4 A Vl(D)/cm3 mol-l - 7.2 1 .O - 7.6 5 0.7 - 7.9 & 0.7 - 8.4 + 1 .O k is the Boltzmann constant, h is Planck's constant, m is the mass of the transferred proton or deuteron, x is the base-width of the unsymmetrical barrier and AHo is the reaction enthalpy. In this calculation of Q the barrier height difference E,(D) - E,(H) was kept constant (5.8 kJ rnol-l, see Appendix), and we used the values of (kfH/kfD)Arrh obtained from Arrhenius plots over the whole range of experimental temperatures.DISCUSSION We are concerned with the evidence of tunnelling at high pressure by examining the reaction rate in solution. The isotope effect on the equilibrium constant is small (tables 1 and 2). On the other hand, as shown in table 4, the values of kinetic isotope ratio, activation energy difference, and ratio of Arrhenius pre-exponential factor are all larger than the semiclassical 13-15 kH/kD > 7-1 I , E,(D) - EJH) > 4.6- 5.8 kJ mol-1 and A(D)/A(H) > 1-1.4. Therefore, tunnelling must occur in the proton-transfer reaction of TNT with EP in acetonitrile not only at atmospheric pressure, but also at high pressure. Table 5 shows that in the TNT+EP reaction, kH/kD decreases very little with increasing pressure at each temperature, though kH/kD for the TNT + DBU reaction decreased ~ignificantly.~ Table 6 also shows that pressure does not affect the tunnelling factor Q(H) significantly.In spite of the tunnelling contribution to both the TNT + DBU and the TNT + EP systems, increasing pressure results in a considerable2964 KINETIC ISOTOPE EFFECTS Table 6. Tunnelling and barrier parameters for the TNT + EP reaction at high pressure and 25 "Ca 1 500 1000 vH/cm-' 868 f 21 845f21 846f21 vD/cm-l 646 & 16 6285 16 629k 16 Q(H> 2.39k0.13 2.25k0.12 2.26 20.12 1.55k0.04 1.51 f0.04 1.51 f0.04 (kH/kD),,l, 16.3 k0.5 15.8k0.5 15.8f0.5 (kHlkD)*,,, 16.2 f 0.3 15.8 f 0.4 15.7 k 0.4 Q(D> a AHo(H) at 1, 500, 1000 bar are 6.7, 8.7 and 10.1 kJ mol-', respectively increase in Q(H) in the f ~ r m e r , ~ but hardly affects Q(H) in the latter.These results lead us to doubt the concept that pressure always reduces the degree of tunnelling, so we will consider further the curvature v of the potential barrier, its dependence on pressure [(a In v/tlp),] and the activation volume AV. The negative values of Ap(H) and Ap(D) in table 5 may indicate that the tran- sition state is more solvated than the initial state. However, when the reaction is subject to tunnelling, the observed activation volume does not accurately represent the volume change from initial state to transition state as defined by the transition- state theory. We evaluated the semiclassical activation volume A @, which should be defined in the absence of tunnelling, according to the procedure described in the previous The activation volume determined experimentally is given by the equation In this equation, A@ = -RT(a In ks/8p)T and A&: = -RT(a In Q/ap),.In the reactions of TNT with EP and DBU we calculated klf and k,D at each pressure (at 25 "C) using the values of k,H, k,D, Q(H) and Q(D). The results are shown in fig. 3. For each reaction the plot of Ink, us. p was linear: A <t(H) and AKi(D) were - 8.4 & 0.6 and - 8.6 0.8 cm3 mol-l, respectively, for TNT+ EP (cf. - 16.4 and - 15.5 cm3 mo1-1 for the TNT + DBU7 system). Values of A KI(H) and A V&D) are similar for the same reaction, but AGt(H) is less negative for the reaction of TNT+EP than for TNT+ DBU. This difference in activation volumes supports the idea that acetonitrile strongly solvates EP even at 1 bar.l0 Tunnelling contributes to the TNT+EP system as Q(H) > 1.However, AL(l(H) and (a In 1 . 1 cm3 mol-l CJ A qs(H) = 7.4 cm3 mol-1 for the TNT+DBU rea~tion].~ A F t can be expressed by the following:' ( 5 ) AVS = A K ~ + A V , ~ . are very small [A &f(H) = 1.2 A &$ = - RT(2 In Q / ~ P ) ~ = - RTf(v) (c? In v / ~ P ) ~ (4) whereflv) = u2/12+u4/720+ . . . ( > 0 ) ; u = hv/kT. Thus, AVI consists of two terms, flv) and (c3lnv/i3p),. As found in eqn (3) and (4), v is directly related to the barrier shape and thence the tunnelling factor Q; e.g. higher barrier height E and shorter barrier distance x make v larger, and favour tunnelling. The magnitude of (a In v/ap), reflects how the barrier dimension changes with pressure through the change of solvating strength, steric hindrance, etc.For the TNT + EP reaction (3 In v / ~ P ) ~ is the same for the proton and deuteronN. SUGIMOTO AND M. SASAKI 2965 2.5 2.0 1 .o 0.5 3*0E 2.5 1 500 1000 plbar Fig. 3. Pressure dependence of Ink, in acetonitrile at 25 "C ; TNT + EP (A), [2H3]TNT + EP (A), TNT+DBU (0) and E2H3]TNT+DBU (a). transfer; - 2.6 x bar-' as calculated from v at 1 and 1000 bar. Thus the difference between AKS(H) and AKt(D) arises mainly from that between flvH) and flvD). However, the difference in AKI(H) between the TNT+EP and the TNT+DBU systems depends not only on the difference inf(vH), but also on the difference in (a In ~ ~ / a p ) ~ . . As (a In vH/i3p), is -8.1 x b a r 1 for the TNT+DBU system, A(d In vH/8p), is 5.5 x b a r 1 for the two systems.This accounts for a con- siderable part of the ratio of A&f(H), 0.16. These results suggest that for a given reaction the effect of pressure on solvation is similar for both proton and deuteron transfer, whereas the extent of this effect differs from reaction to reaction. The smaller magnitude of (a In vH/8p), for TNT + EP indicates that acetonitrile solvates the reactant and activated complex to a considerable extent even at 1 bar. Therefore, enhancing the degree of solvent coupling has a greater effect than increasing the pressure for this system. It is noteworthy that (a In Q/ap), is very small even when Q is sufficiently large for tunnelling to be considered. This result shows that even if tunnelling occurs, and kH/kD is large enough, the magnitude of (a in v/ap), is possibly small in some reactions for which kH/kD decreases little with l6 This also raises some doubt about the former concept that [a (kH/kD)/ap], = 0, and thus (a In Q / ~ P ) ~ = 0, lead directly to Q = 1, i.e.it is doubtful that a significant change in kH/kD with pressure is a suitable criterion for determining the occurrence of tunnelling. Hence, in the study of the effect of pressure on tunnelling it is very important to obtain not only kH/kD, but also Q at high pressure and to consider (a In Q / a p ) , in terms offlv) and (2 In vlap), as described in this paper. APPENDIX It is usually assumed that E(D) - E(H) is the same at 1 bar as at high pressure. We have calculated the values of kH/kD at 25 "C as a function of v(H) (fig.4). Up to a few kilobars the zero-point energies of molecules would remain almost unchanged.l?2966 KINETIC ISOTOPE EFFECTS 20 15 C Y -Y 10 5 0 I 1 I I I I 700 800 900 loo0 1100 1200 v( H)/crn-l Fig. 4. Change of kH/kD at 25 "C with u(H) for various A {A = [E,(D)-E,(H)]}. E,(D) = 14.0 and AH"(H) = 1.6 kcal mo1-'.* A = (a) 1.4, (b) 1.2, (c) 1.0, ( d ) 0.8, ( e ) 0.6, (f) 0.4 and (g) 0.2 kcal mol-I. Consequently, the decrease of kH/kD with pressure could be regarded as resulting from the decrease of the tunnelling factor Q(H) (A -+ B in fig. 4). However, at much higher pressure or in protic solvents, A[E,(D)-E,(H)] could change with pressure (A -+ C in fig. 4). In such a case, the variation of kH/kD with pressure may not correspond directly to variation of v(H) and the tunnelling factor Q(H).In other words, the variation of kinetic isotope rate ratio with pressure does not always become a criterion for tunnelling phenomenon. It is important to know quantitatively the tunnelling factor Q(H) based on the temperature dependence of kH/kD even at high pressure. (a) N. S. Isaacs, K. Javaid and E. Rannala, J. Chem. SOC., Perkin Trans. 2, 1978, 709; (b) N. S. Isaacs and K. Javaid, J. Chem. SOC., Perkin Trans. 2, 1979, 1583. D. A. Palmer and H. Kelm, Aust. J. Chem., 1977, 30, 1229. (a) M. Sasaki, N. Sugimoto and J. Osugi, Chem. Lett., 1980, 887; (b) N. Sugimoto, M. Sasaki and J. Osugi, Bull. Znst. Chem. Res., Kyoto Univ., 1981, 59, 63. E. F. Caldin and S. Mateo, J. Chem. SOC., Faraday Trans. I, 1975, 71, 1876. N. Sugimoto, M. Sasaki and J. Osugi, Bull. Chem. SOC. Jpn, 1981, 54, 2598. N. Sugimoto, M. Sasaki and J. Osugi, J. Phys. Chem., 1982, 86, 3418. N. Sugimoto, M. Sasaki and J. Osugi, J . Am. Chem. SOC., 1983, 105, 7676. N. Sugimoto, M. Sasaki and J. Osugi, Bull. Chem. SOC. Jpn, 1984, 57, 366. N. Sugimoto, M. Sasaki and J. Osugi, J. Chem. SOC., Perkin Trans. 2, 1984, 655. lo N. Sugimoto and M. Sasaki, J. Chem. SOC., Faraday Trans. I , 1985,81, 1441. l1 M. Sasaki, F. Amita and J. Osugi, Rev. Sci. Instrum., 1979, 50, 1 104. l2 K. R. Srinivasan and R. L. Kay, J. Solution Chem., 1977, 6, 357. l3 R. P. Bell, The Tunnel Effecf in Chemistry (Chapman and Hall, London, 1980). l4 E. F. Caldin and V. Gold, Proton-transfer Reactions (Chapman and Hall, London, 1975). l5 L. Melander and W. H. Saunders Jr, Reaction Rates of Isotopic Molecules (Wiley, New York, 2nd l6 N. Nishimura and T. Motoyama, Bull. Chem. SOC. Jpn, 1984, 57, 1. edn, 1980). (PAPER 5/072) * 1 kcal = 4.181 kJ.

ISSN:0300-9599    

DOI:10.1039/F19858102959

出版商:RSC    

年代:1985

数据来源: RSC