ISSN:0005-9021    

DOI:10.1002/bbpc.19820861002

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1982

数据来源: WILEY

摘要:

AbstractThe energy of the electronic levels in ammonia vapor which are populated by the photoinjection of excess electrons has been determined in the density range from 1.7 · 1017to 2.3 . 1021molecules/cm3at T = 400 K. The method used is based on measuring the photoelectric work function of a stainless steel photocathode immersed in ammonia vapor with respect to that into vacuum. From these measurements the chemical potential of two bands of electron injection levels can be elucidated. These results are discussed together with electron mobilities which show with increasing vapor density a transition from the quasi‐free to the localized electron state. It will be shown that the onset of electron localization obeys Mott's criterion for quantum localization. From these results together with the optical absorption spectra of solvated electrons, and from theoretical considerations it follows that one of the injection bands is the conduction band. The other one is formed by pre‐existing solvent traps. Therefore, in contrast to the conventional assumption in the theory of photoemission, the electron injection into polar media does not occur only in the conduction band but also in pre‐existing trap states (band‐tail states) thus supporting Thompson's recent assertion. This requires the reinterpretation of existing data on photoemission of electrons into polar solvents (electrolytes) including the photoionization of solute molecules in polar solvents in order to determine the bottom of the conductio

ISSN:0005-9021    

DOI:10.1002/bbpc.19820861003

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1982

数据来源: WILEY

摘要:

AbstractA compilation of the thermodynamics of simple ions in ammonia is given, based on thermodynamic data of their salts, on some electrochemical data and on those of solvated electrons. The final data are expressed in terms of the solvation enthalpies, solvation entropies and electrode potentials of the ions. With the uncertainties of the work function of the metals and that of the surface potential of the solvent, the concept that solvated electrons are partner of any redox equilibria allows the calculation of the “absolute” electrode equilibrium potential of any electrode in contact with the solution of any redox pair. This is exemplified for a cesium and a silver electrode in ammonia. ‐ Finally the differences in the kinetics of solvated electrons in water and in ammonia with respect to the reaction with the solvent are expressed qualitatively by the transition state theory making use of the thermodynamic data of the solvated electrons. The high stability of electrons in ammonia is due to their very high positive partial molar en

ISSN:0005-9021    

DOI:10.1002/bbpc.19820861004

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1982

数据来源: WILEY

摘要:

AbstractIn order to carry out electromotive force measurements in molten chlorides at temperatures up to 850°C a reversible formation cell using a chlorine/chloride reference electrode of graphite was constructed. The formation potential of molten AgCl in liquid mixture with KCl and with KCl, LiCl depending on temperature was determined for several concentrations. The excess properties of the binary system AgCl, KCl were calculated. An analytical thermodynamical description of the ternary system AgCl, KCl, LiCl was made by means of literature data for the appropriate binary systems employing the Redlich‐Kister equation for the integral excess free energy. The results achieved thereby were verified by the measurements made in this wo

ISSN:0005-9021    

DOI:10.1002/bbpc.19820861005

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1982

数据来源: WILEY

摘要:

AbstractEquilibrium vaporization behaviour of twelve IIB/VIA‐compounds of the type MeX was studied by means of high‐temperature mass spectrometry. In all cases except HgTe the existence of stable MeX(g)‐molecules was established. Bond energiesD0(MeXgas) were determined by the thermodynamic third‐law method and range as follows: ZnO(g) (280.1 kJ/mol)/ZnS(g) (224.8)/ZnSe(g) (170.8)/ZnTe(g) (117.7)/CdO(g) (230.3)/CdS(g) (208.5)/CdSe(g) (127.7)/CdTe(g) (100.1)/HgO(g) (221.1)/HgS(g) (217.3)/HgSe(g) (144.5). ‐ Comparison of the third‐law bond energies with existing experimental data, upper limits ofD0given by other authors, and semi‐empirical estimates shows basic agreement. Data for the heat of dissociative vaporizationΔH0R, the heat of atomizationΔH0at, the parameter, and the chemical stabilities of the IIB/VIA‐systems a

ISSN:0005-9021    

DOI:10.1002/bbpc.19820861006

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1982

数据来源: WILEY

摘要:

AbstractDeposited films of merocyanine dye (3‐carboxymethyl‐5‐[2‐(3‐octadecyl‐2‐benzothiazolinylidene)ethylidene]‐2‐thioxo‐4‐thiazolidinone) show various kinds of intra‐ and intermolecular changes when they are heated and/or soaked in a neutral aqueous solution. The effect of such changes on photocurrent has been examined using electrodes coated with the dye film. A remarkable high quantum efficiency (above 10%) for cathodic photocurrent has been obtained when the dye film shows red‐shifted absorption bands owing to the dye aggregation. The high photoactivity is attributable to the high transfering ability of e

ISSN:0005-9021    

DOI:10.1002/bbpc.19820861007

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1982

数据来源: WILEY

摘要:

AbstractThe analysis of the amplitudes inT‐jump experiments on aqueous micellar solutions yields the dependence of the critical micelle concentration and the mean aggregation numbermof the micelles on temperature, whereasp‐jump experiments yield the corresponding dependence on pressure. In this paper we have, accordingly, evaluated the dependence ofmon the total detergent concentration from stopped‐flow amplitudes (i.e. from concentration‐jump experiments). The experiments were performed on H2O‐NaDS and H2O‐NaDS. It turned out that the mean aggregation number of these detergents appears to increase with increasing detergent concentration, in accord with the results of other authors who have found an increase ofmwith increasing concentration of an added

ISSN:0005-9021    

DOI:10.1002/bbpc.19820861008

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1982

数据来源: WILEY

摘要:

AbstractStarting from the calculation of the dielectric polarization of a macroscopic ellipsoid containing a fluid of polarizable dipoles surrounded by a uniform dielectric by means of electrostatics the macroscopic expressions of the dipole fluctuations are derived as a generalization of the Fröhlich relations concerning a sphere. The result holds for polar, non‐polar, and non‐polarizable molecules and includes samples of spherical, disc and needle geometry surrounded by vacuum, a metal or a medium of the same dielectric constant. The explicit evaluation of the reaction field leads independently of the surrounding medium to the same expressions which hold for samples in vacuum. The evaluation of the dipolar long‐range terms inside the sample leads to expressions of the form of the Clausius‐Mossotti relation which are independent of the boundary conditions and depend on the molecular properties and short‐range correlations only. Considering a sample containing only one molecule the theory leads to a generalization of the Onsager model for ellipsoidal molecules which agrees for small deviations of the spherical shape with the Böttcher‐

ISSN:0005-9021    

DOI:10.1002/bbpc.19820861009

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1982

数据来源: WILEY

摘要:

AbstractSpontaneous and Hg2+‐induced aquation reactions of Co(NH3)5SO4+are studied in the presence of sodium polyethylenesulfonate and sodium polystyrenesulfonate under high pressure. The spontaneous aquation rates are in the order of Co(NH3)5SO4+, Co(NH3)5Br2+and Cr(NH3)5Br2+and is accounted for in terms of the Brönsted‐Bjerrum theory. The volume of activation (ΔV#) of both spontaneous and Hg2+‐induced aquations of Co(NH3)5SO4+greatly increased by addition of the macroions, which is attributed to stronger desolvation of the activated complex than the reactant in the strong electrostatic field of the ma

ISSN:0005-9021    

DOI:10.1002/bbpc.19820861010

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1982

数据来源: WILEY

摘要:

AbstractThe effect of pressure on the reaction between Fe(III) and NCS−ions was reinvestigated using a recently constructed high‐pressure Joule‐heating temperature‐jump instrument. The results differ significantly from those reported by Jost [1], and the volumes of activation for the reactions of Fe(OH2)63+and Fe(OH2)5OH2+with NCS−are 6.7 ± 0.4 and ∼0 cm3mol−1, respectively, at 20°C. The pressure dependences of the Fe(OH2)33+/Fe(OH2)5OH2+and Fe(OH2)63+, NCS−/Fe(OH2)5NCS2+equilibria are in good agreement with earlier findings. The significance of the results are discussed in reference to recent data on the solvent exchange and substitution rea

ISSN:0005-9021    

DOI:10.1002/bbpc.19820861011

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1982

数据来源: WILEY