摘要:

J . Chrm. SOC., Faraday Trans. I, 1982, 78, 2297-2302 Magneto-optical Rotation Studies of Liquid Mixtures Part 6.-Specific Interactions in Mixtures of CCl, with Aliphatic and Aromatic Ketones and Esters BY J. GRAHAM DAWBER Department of Chemistry and Biology, North Staffordshire Polytechnic, Stoke-on-Trent ST4 2DE Received 18th November, 198 1 Measurements have been made of the magneto-optical rotations at 435.8 nm of binary mixtures of CCl, with 35 aliphatic and aromatic ketones and esters. The departure from ideality of each binary mixture was treated in terms of an excess magnetic rotation, aE ; for many systems, particularly the aromatic compounds, the variation of a E with composition gave indications of interaction between the CCl, and the other component. The results for the longer-chain aliphatic compounds indicated that their liquids contain orientational order which was broken up by addition of the CCl,.The molar magnetic rotations, Am, were calculated from the results and compared with the values calculated from a set of partial magnetic rotation parameters obtained previously. In most cases the agreement was quite good thus confirming the approximate additivity of the Faraday effect. Previous studies'. on the magneto-optical rotations of binary mixtures of miscible liquids have shown that the departures from ideality of the systems could be expressed in terms of an excess magnetic rotation, aE. The variations of aE with liquid composition were used to give an indication of the overall changes occurring in the liquid state. In some mixtures in which CCl, was one of the components there were indications that weak charge-transfer complexes were formed, particularly when the other component was an aromatic compound, although this also occurred, albeit to a lesser extent, with aliphatic amines, ethers and alcohols.For some mixtures the changes in aE could be interpreted in terms of a breakdown of order in the liquid structure of the second component by the addition of CCl,. Many of the systems previously studied1* had been investigated by other workers using a variety of techniques and the magneto-optical studies complemented their findings. In the work presented here we have extended these studies to mixtures of compounds which have not been studied by other techniques, and have included in the investigation aliphatic and aromatic ketones and esters in order to study the possible interaction of the carbonyl group with CC1,.EXPERIMENTAL The magnetic rotation apparatus has been described previ~usly.l-~ The measurements of magnetic rotation were made at the 435.8 nm line of the Hg emission spectrum with the sample in a 1 cm path-length cell placed in a magnetic flux density of 0.54 T. The wavelength used was well outside the electronic absorption bands of all the substances studied. The compounds were of laboratory reagent grade and were dried with common drying agents. Mixtures of CCl, + the second component were made up to cover the whole composition range. The temperature of the liquids was nominally 20 O C . Readings of angular rotation could be estimated to 0.001*.22972298 MAGNETO-OPTICAL ROTATION STUDIES OF LIQUID MIXTURES RESULTS The results were first of all calculated as magnetic rotation, a,, defined as (1) a, = 8,/1 where 8, is the magnetic rotation of the solution in a magnetic flux density of 1 T and 1 is the path-length of the solution in metres. The units of a, are thus deg m-' T-'. TABLE 1 .-MAGNETO-OPTICAL PARAMETERS OF PURE LIQUIDS (Or: AND Am) AND MAXIMUM EXCESS MAGNETIC ROTATIONS (a:,,.) OF THEIR MIXTURES WITH CC1, AT 436 nm AND 20 "C compound acetaldehyde propan-2-one (acetone) butan-2-one 4-methylpentan-2-one nonan-5-one 2,6-dimethylheptan-4-one heptan-2-one acetophenone 1 -phenylpropan- 1 -one p-me thy lace tophenone 1 -phenylpropan-2-one propanal methyl formate ethyl formate methyl ethanoate ethyl ethanoate n-propyl ethanoate isopropyl ethanoate n-butyl ethanoate n-pentyl ethanoate isopentyl ethanoate ethyl propionate ethyl n-butyrate n-butyl n-butyrate isobutyl n-butyrate glyceryl tributyrate methyl benzoate ethyl benzoate isopropyl benzoate n-butyl benzoate benzyl ethanoate benzyl benzoate diethyl phthalate ethyl acetoace ta te pentane-2,4-dione (acetyl acetone) 336.1 335.9 356.6 382.5 385.2 402.7 38 1 .O 781.0 755.1 744.1 788.0 347.9 284.7 330.4 305.1 320.3 338.7 336.3 346.4 366.7 378.7 352.2 345.3 360.6 365.1 371.2 752.4 720.7 684.0 665.3 754.6 962.1 617.2 360.8 512.2 18.9 24.7 31.9 47.9 66.6 71.1 53.4 91.5 100.3 99.4 105.7 25.0 17.6 26.6 24.2 31.4 38.9 39.3 45.8 54.6 56.6 40.4 45.7 60.0 60.2 108.5 94.1 107.9 110.4 118.6 107.5 183.0 122.8 45.7 52.6 17.0 17.5 24.5 10.2 32.0 3.0 47.0 -9.5 69.5 -14.4 69.5 -12.6 54.5 - 7.2 100.5 28.0 108.0 27.8 104.5 31.2 108.0 32.0 24.5 - 17.0 23.4 24.5 4.4 24.5 5.3 4.7 32.0 -2.2 39.5 -10.0 39.5 -10.6 47.0 -14.3 54.5 -20.4 54.5 -12.6 39.5 - 9.0 47.0 -14.4 62.0 -19.8 62.0 -16.8 136.0 -35.0 100.5 24.0 24.0 108.0 30.3 115.5 31.0 123.5 31.5 108.0 32.6 183.0 87.0 128.0 26.8 48.0 -7.5 40.5 11.1 0.38 0.48 0.35 0.62 0.56 0.55 0.58 0.55 0.52 0.60 0.60 0.50 0.48 0.36 0.68 0.52 0.50 0.54 0.58 0.52 0.54 0.54 0.54 0.54 0.55 0.67 0.37 0.65 0.55 0.54 0.55 0.57 0.65 0.55 0.43 0.50 - Ai for 0 in OR of R'COOR = 0.0.J .G. DAWBER 2299 The values of aO, for the single liquids are given in table 1. The molar magnetic rotations, A,, defined as A, = aO,M/d were calculated, where d is density (kg mP3) and M is molecular weight, and these are also given in table 1 as Am(obs.).The non-ideality of the liquid mixtures was expressed in terms of the excess magnetic rotation, a E , which is defined as (2) aE = a,-(X,aO,,+X,aO,,) (3) where X , and X , are the mole fractions of components 1 and 2 in the mixture, and a;, and a;, are the magnetic rotations of the pure components. The values of aE for 6 4 2 - 0 F E d I Do - 2 a il . - 4 - 6 -8 -1 0 -12 -14 mole fraction of CC14 FIG. 1 .-Excess magnetic rotations of binary mixtures of CCl, with aliphatic ketones. (a) Propan-2-one, (b) butan-2-one, ( c ) heptan-2-one, ( d ) 4-methylpentan-2-one, (e) 2,6-dimethylheptan-4-one, (f) nonan- 5-one.2300 MAGNETO-OPTICAL ROTATION STUDIES OF LIQUID MIXTURES the various binary mixtures were plotted as a function of XCcl4 and the maximum values of aE and the corresponding values of XCcl4 are given in table 1.A typical set of graphs for a selection of ketones in binary mixtures with CC1, are shown in There are several possible reasons for the changes in aE as the liquid composition is changed. These include the association or depolymerisation (i.e. breakdown of structure) of the components, or specific molecular interactions between the two components in the mixture. From previous work1. 2 y it was found that the aE results can best be interpreted if CCl, is regarded as an unassociated liquid, and that depolymerisation of the other component by the CCl, is accompanied by negative aE values. On the other hand, specific interaction between the CCl, and the other component will be accompanied by positive aE values.fig. 1. DISCUSSION ADDITIVITY OF THE MOLAR MAGNETIC ROTATION, Am In a previous paper6 a set of partial magnetic rotation parameters, Ai, were deduced empirically from measurements made on 72 compounds. Using these partial parameters, values of Am were calculated for the compounds used in this work, and these are presented as in table 1. An additional partial parameter was used in the calculation, namely, Ai for the oxygen atom in the acyl group of esters was given a value of 0.0 rather than a value of 4.0 which was used for alcohols.6 The values of Am(,bs.) and Am(calc.) are compared in table 1. For the 35 compounds studied in this work the majority of the A,(obs.) and Am(c?lc.) agree quite well, thus confirming the additive property of the molar magnetic rotation.The poorest agreement was for acetophenone, propiophenone,p-methyl acetophenone, glyceryl tributyrate, ethyl acetoacetate and pentane-2,4-dione (acetyl acetone). In the case of the phenone group of compounds the possible conjugation of the carbonyl group with the phenyl ring may account for the discrepancy between the calculated and observed Am values. Ethyl acetoacetate and pentane-2,4-dione exist partially in the enol form and this would certainly influence the value of Am(,bs.). The large molar magnetic rotation. A,/deg m2 mol T-' kg-' FIG. 2.-Relationship between [R] and A, for aliphatic compounds. 0, this work; x , ref. ( 6 ) .J. G .DAWBER 230 1 discrepancy for glyceryl tributyrate may be due to the large inter- and intra-molecular interaction in the liquid state. Molar refraction, [R], defined as (n2 - 1) M/(n2 + 2) d, has additive properties and values of [R] were calculated from the refractive indices, n; at the sodium D-line.' The values of [R] for the aliphatic compounds of this work are plotted against Am(obs.) in fig. 2. Also plotted for comparison are the values for the aliphatic compounds from the previous study.6 The correlation between Am(obs.) and [R] for both sets of data is reasonable. (N.B. the [R] scales in fig. 2 and 3 of ref. (6) are incorrect by a factor of 2, i.e. the [R] scale should read 0 to 60 cm3 and not 0 to 30 cm3 as shown.) MIXTURES OF CCl,+KETONES The interaction between CCl, and aliphatic ketones in a binary mixture, as judged by the aE values, seems to be markedly influenced by the substituents around the carbonyl group (table 1 and fig.1). The largest effect amongst the aliphatic compounds is with acetaldehyde but this interaction may involve hydrogen bonding with a chlorine atom in CCl, in addition to interaction of the carbonyl group in charge transfer from the n-electrons to a vacant d-orbital of a second chlorine atom. The interaction with CC1, decreases going from propan-2-one (acetone) to butan-2-one, probably owing to the slight loss of accessibility of the carbonyl group. For the remainder of the aliphatic ketones the values of aE are negative. These negative values are indicative of structure breaking of the liquid structure of the ketone by the CC1,.Thermodynamic studies of linear- and branched-chain alkanes indicate that there is orientational order among the long chains of a n-alkane and that this can be disturbed by addition of a more spherical mo1ecule.8-11 These observations were confirmed by our magneto-optical studies.2 It seems from the present work that a similar effect is observed for ketones and that the longer-chain members have some orientational order in the liquid state which is broken up by the addition of the CCl,, and that this masks any interaction which may occur between the carbonyl group and the CCl, molecule. For all of the mixtures of aromatic ketones with CCl,, aE was strongly positive indicating interaction of the ketone with the CCl,. There is a variety of evidence which suggests that aromatic hydrocarbons form charge-transfer complexes with CCl,.12-22 From previous experience with aromatic hydrocarbons and aminesly 2 v we conclude that these effects are also observed in magneto-optical studies and that the interaction of aromatic compounds with CCI, is via a charge-transfer complex involving the aromatic n-electrons acting as the donor.The results of this work (the aE values in table 1) also suggest that this is the principal interaction of the aromatic ketones with CCl, rather than involving the carbonyl group. The aE values suggest that the extent of charge-transfer interaction is approximately related to the n-electron availability in the aromatic ring. MIXTURES OF CCl,+ESTERS The values of aE for mixtures of esters with CCl, (table 1) follow a similar pattern to those for the ketones. For the aliphatic esters positive values of aE for the lower members of the series indicate that the interaction with the CCl, falls off as the molecular size is increased.The interaction could be via the carbonyl group or the oxygen atom of the acyl group, but comparison with the ketones indicates that the interaction is likely to involve the carbonyl group. The longer-chain aliphatic members, like the ketones, have negative values of aE indicating an orientational order of the molecules in the liquid state which is broken up by the CCl,. The effect increases with chain length and is greatest for glyceryl tributyrate.2302 MAGNETO-OPTICAL ROTATION STUDIES OF LIQUID MIXTURES The aE values for the aromatic esters are all positive and indicate interactions of similar magnitude to other aromatic compounds, with aE being roughly correlated with the n-electron availability.In the case of benzyl benzoate the interaction is considerable. Again the interaction is likely to involve the n-electrons of the aromatic system as the donor and a vacant d-orbital ofa C1 atom in CCl, in a weak charge-transfer complex. The magneto-optical technique is not one of direct observation of complex formation. Although the method assumes that the departure from an ideal mixture law can be interpreted in terms of a chemical effect, it is possible to correlate the aE values in terms of structure breaking in the liquid mixture or in terms of the formation of weak complexes.In some cases both effects could be present (e.g. the aliphatic ketones and esters) but the magneto-optical method will in general only detect the effect which is predominant. The author acknowledges with thanks the financial assistance of the S.R.C. towards the cost of the polarimeter. J. G. Dawber, J . Chem. SOC., Faraday Trans. I , 1978, 74, 1702 and 1710. J. G. Dawber, J . Chem. Soc., Faraday Trans. I , 1979, 75, 370. J. G. Dawber, J . Chem. SOC., Faraday Trans. 2, 1974, 70, 597. J. G . Dawber, J . Chem. Sac., Faraday Trans. I , 1978, 74, 960. J. G. Dawber, J . Chem. Soc., Faraday Trans. 1, 1982, 78, 1127. J. G. Dawber, J . Chem. SOC., Faraday Trans. 2, 1980, 76, 1324. Handbook of Chemistry and Physics (The Chemical Rubber Co., Cleveland, Ohio, 60th edn, 1980). S. Turrell and G. Delmas, J . Chem. SOC., Faraday Trans. 1, 1974, 70, 572. V. Te Lam, P. Picker, D. Patterson and P. Tancrede, J. Chem. Soc., Faraday Trans. 2, 1974,70, 1465 and 1479. lo G. Delmas and Ng. T. Thank, J . Chem. SOC., Faraday Trans. I , 1975, 71, 1172. l 1 G. Delmas and P. Purves, J . Chem. SOC., Faraday Trans. 2, 1977, 73, 1828 and 1838. It G. H. Cheeseman and A. M. B. Whitaker, Proc. R . Soc. London, Ser. A, 1952, 212, 406. l3 L. A. K. Staveley, W. J. Tupman and K. B. Hert, Trans. Faraday SOC., 1955, 51, 328. l 4 M. L. McGlashan, Annu. Rev. Phys. Chem., 1962, 13, 409. l5 G. R. Coates, R. J. Sullivan and J. B. Ott, J . Phys. Chem., 1959, 63, 589. l6 R. Anderson and J. M. Prausnitz, J. Chem. Phys., 1963, 39, 1225. J. B. Ott, J. R. Coates and A. H. Budge, J. Phys. Chem., 1963, 67, 1225. R. P. Rastogi and R. K. Nigam, Trans. Faraday Soc., 1959, 55, 2005. l 9 J. B. Ott, J. R. Coates and A. H. Budge, J. Phys. Chem., 1962, 66, 1387. R. P. Rastogi, J. Nath and R. R. Misra, J. Chem. Thermodyn., 1971, 3, 307. 21 A. Ahmed, J . Chem. Soc., Faraday Trans. I , 1973, 59, 540. 22 M. L. McGlashan, D. Stubley and H. Watts, J . Chem. Soc. A , 1969, 673. (PAPER 1 / 1797)

ISSN:0300-9599    

DOI:10.1039/F19827802297

出版商:RSC    

年代:1982

数据来源: RSC

摘要:

Reviews of Books EXAFS Spectroscopy, Techniques and Applications. Ed. by B. K. TEO and D. C. JOY. (Plenum Press, New York, 1981). Pp. viii+275. Price E32.50. Extended X-Ray Absorption Fine Structure (EXAFS) is a technique which is being increasingly applied to study the structure of matter. Oscillatory variations in absorption cross-section which are observed near the absorption edge of a particular element contain information on the local structure surrounding that element. The method is of great usefulness for amorphous and poorly ordered materials, the parameters determined being interatomic distance (to & 0.001 nm), coordination number (to ca. 20%) and Debye-Waller factor. Since the experiment is most satisfactorily performed with synchrotron radiation and there is a lively debate on the best procedures of data analysis, the technique is still at a formative stage of development.This book, which is the record of a conference held in November 1979, is thus already dated. A more serious flaw is the lop-sided coverage and wholly American perspective which this volume affords. Twenty-one chapters of widely varying length are presented, thirteen of which are devoted to conventional EXAFS studies. Three chapters consider individual synchrotron sources and are of doubtful relevance to the title. The last five chapters, which concern the use of electron beams to generate EXAFS-like structure, represent the most interesting section of the book. The first chapter is a brief description of the history of the field prior to the renaissance of interest in the 1970s.Lee then gives a brief and perfunctory account of the theory of EXAFS in the single-scattering, plane-wave approximation. The third chapter, by Teo, has the same title as the book and occupies forty-six pages. He again discusses the theory, paying particular attention to thermal and static disorder effects, inelastic scattering, multiple scattering and the energy-threshold problem. A description of one approach to data analysis is then followed by an account of the experimental arrangement. Three pages of text are devoted to biological applications - a major area of importance for EXAFS which is mentioned nowhere else in these proceedings. Lastly, Teo briefly reviews some applications to inorganic systems. Chap. 4 and 5 are devoted to some problems in data analysis while chap.6 to 11 concern specific areas of application. These are metals and semiconductors (Crozier), superionic conductors (Boyce and Hayes), high-pressure studies (Ingalls et a,.), solutions (Sandstrom, Stults and Greegor), supported catalysts (Via, Sinfelt and Lytle) and amorphous materials (Hunter). These chapters will doubtless be of interest to specialists, although that on catalysts is too short to be of use. Chap. 12 and 13 concern fluorescence detection and studies of dilute systems. Chap. 14 reviews other synchrotron techniques studied at Stanford while chap. 15 and 16, respectively, describe the Cornell synchrotron and the Brookhaven National Synchrotron Source. Chap. 17 to 21 concern extended energy-loss fine structure (EXELFS), which has a similar origin and yields similar information to that found in EXAFS. Joy introduces the technique, which is described in more detail, together with some applications in the chapter by Leapman et al.Csillag, Johnson and Stern then discuss EXELFS in the electron microscope. The last chapters concern a comparison of electron and photon sources (Utlaut) and the potential for radiation damage in EXAFS and EXELFS (Isaacson). The book contains quite a lot of material of interest and is well produced, most of the chapters being clearly written. There is a short subject-index. The arrangement of material is however unhelpful to the beginner in EXAFS while the coverage of applications is unbalanced and patchy. Most of the transmission EXAFS material is more clearly covered elsewhere [see, e.g., Synchrotron Radiation, ed.H. Winick and S. Doniach (Plenum Press, New York, 1980)l. The main contribution of this volume is in the chapters on EXELFS and its relation to EXAFS. Received 4th September, 198 1 R. W. JOYNER 23032304 REVIEWS OF BOOKS Advances in Solution Chemistry. Ed. by I. BERTINI, L. LUNAZZI and A. DEI. (Plenum Press, This book illustrates the problems of edited multi-author volumes based on conference proceedings. Here is a mixture of invited review lectures and accounts of original and specialist research, delivered at the 5th IUPAC Symposium on Solute-Solute-Solvent Interactions (SSSI). The volume contains the residue after the separate publication of the plenary lectures and several microsymposia.To complicate matters further, one of the microsymposia (Evaluation of Solvation Energies of Reagents and Transition States) is in fact included, although it is not obvious to me which of the chapters constitute the microsymposium. Even interpreting SSSI in its most generous sense, it is hard to see how all the articles in this volume can be accommodated under such a heading. The topics range from ‘real’ solution chemistry, via coordination chemistry, to n.m.r. studies of Mg and Ca involvement in biological processes, the native conformations of neurotoxins, liquid crystals in organic chemistry, the function of synthetic membranes and mechanisms of organic reactions. According to the preface, ‘the choice of lecturers has been based on the scientific prestige of the con- tributors.. . and, although to a lesser extent, following a geographical criterion’. Those familiar with the inner workings of IUPAC may wonder whether the geographical criterion did not perhaps take precedence after all: the 26 chapters are shared by authors from 16 countries. In the absence of ruthless editing, such an international collection of articles was bound to be uneven. This book certainly contains its share of linguistic ambiguity, some of it quite amusing. On the whole, however, it is well produced, one of the best camera-ready products I have come across. The editors took a calculated risk when they decided, in the interest of speedy publication, not to return the retyped texts to the authors for correction. On balance, their gamble was successful.As to the quality and usefulness of the various contributions, these vary. Some of the chapters are true masterpieces, packed with information and critical analysis. For instance, the review by Cabani of the aqueous solution thermodynamics of simple organic compounds provides a balanced account of the available data and their interpretation (1 56 references). Another highlight is the account by Forsen et al. of calcium, magnesium and cadmium n.m.r. as used to study the function of ions in isolated troponin C, calmodulin and phospholipase A. The essay demonstrates the potential of the techniques for probing the subtle processes which play such an important role in the proper functioning of living organisms. A thoughtful combination of different techniques has led to the elucidation of many different peptide conformations.Bystrov et al. describe such a study applied to the structure determination of peptide toxins isolated from honey-bee venom and cobra venom, the eventual aim being the topological mapping of the acetylcholine binding site. Finally, for special commendation I cite Galli et al. for their review of solvation effects in intramolecular cyclisation reactions. Of the remainder, several chapters will be of use to a range of specialists. Seven papers deal with various aspects of coordination chemistry. I found the article on synthetic oxygen carriers (Jezowska-Trzebiatowska and Vogt) particularly interesting. Whether such studies will, as the authors claim, clarify the mechanisms of biological oxygen carriers, remains to be seen, but synthetic oxygen transport is an interesting subject in its own right.Pride of place is given to Resch and Gutmann, who, in the first chapter of the book, propose the thesis that ‘the existence of a liquid would be impossible in the complete absence of impurities, voids or ions’. Their new theory smacks of metaphysics and lies so far removed from liquid-state physics, as currently practised, that I find the arguments incomprehensible. Their understanding is not made any easier by the several references to as-yet-unpublished work. In favour of the book: high standard of production and some excellent and topical state-of-the-art reviews by acknowledged authorities. Against : heterogeneity of subject-matter, strays far from SSSI, variability of quality of presentation and mixture of specialist chapters and reviews.New York, 1981). Pp. ix + 387. Price $49.50. F. FRANKS Received 19th August, 1981REVIEWS OF BOOKS 2305 Surfactant Science Series, Volume 11. Anionic Surfactants. Physical Chemistry of Surfactant Action. Ed. by E. H. LUCASSEN-REYNDERS. (Marcel Dekker, New York, 1981). Pp. xi +412. Price SFr 148. It is 14 years since the first book in this series was published. That volume, on non-ionic surfactants, contained some notable contributions on surfactant physical chemistry. Now, in this, the fourth of a set of volumes on anionic surfactants, the editor has brought together a group of experts whose contributions rival their predecessors’ in quality. Wisely deciding not to restrict discussion solely to anionic surfactants but to deal with all types, they have written eight chapters covering a wide range of topics.In chap. 1, Adsorption at Fluid Interfaces, E. H. Lucassen-Reynders gives a short description of empirical behaviour followed by a detailed and careful discussion of theoretical interpretation using ‘2-D gas’ and ‘2-D solution’ thermodynamic approaches. The author has used the latter method to make significant contributions to the theory of surfactant mixtures and her interest in this topic is shown by the welcome inclusion of a large section on mixtures. In chap. 2, Surfactant Solutions: Dilute and Concentrated, D. G. Hall and G. J. T. Tiddy devote most of their discussion to dilute micellar systems and have managed to condense the enormous amount of published work into a clear and comprehensive review which includes a short exposition of the Kirkwood-Buff multiple-equilibrium approach to the thermodynamics of micellisation developed by Dr Hall.The section on concentrated surfactant solutions is shorter and more qualitative, reflecting the lesser understanding of interactions in such systems. There could perhaps have been more discussion of the roles of molecular geometry and intermolecular forces in surfactant phase transitions. Chap. 3, Polymer/Surfactant Interactions, by I. D. Robb, fills a gap in surfactant reviews by discussing the interaction of surfactant with ionic and non-ionic synthetic polymers as well as covering the more familiar surfactant/protein work. This topic is attracting increasing interest and Dr Robb’s review provides an informative and perspicacious introduction to what is still largely an empirical subject where many questions concerning the exact nature of the polymer-surfactant binding process remain to be answered.Chap. 4, Adsorption at Solid/Liquid Interfaces, by C. H. Giles, is a broad and rather idiosyncratic survey in which much space is devoted to historical review and phenomenological classification of isotherms and very little to a ‘ state-of-the-art’ discussion of surfactant adsorption. In chap. 5, Surface Elasticity and Viscosity in Compression/Dilation, Dr Lucassen-Reynders considers the rheology of adsorbed surfactant at liquid interfaces. This topic, which can so easily be made obscure to the non-specialist reader, is lucidly discussed.Towards the end of the chapter there is a good summary of the applications of measurements of surface viscoelasticity which not only highlights their potential usefulness but also gives a realistic assessment of their limitations. Chap. 6, Dynamic Properties of Free Liquid Films and Foams, by J. Lucassen, is a thought-provoking discussion of the dynamic mechanisms responsible for the stability or rupture of foam films. Most space is devoted to isolated films, both thick and thin, but there is also an analysis of the interaction between the film and its Plateau border and some useful discussion on the properties of integral foams. The chapter ends with a short section on foam characteristics and the nature of the surfactant that serves to emphasise how little is actually known about the relationship between surfactant structure and foam properties.In chap. 7, Effects of Adsorption on Detergency, M. J. Schwuger, faced with the daunting task of identifying the important features of adsorption in detergency processes which invariably involve a plethora of interfaces and substrate types, has restricted his discussion to the removal of solid soil. He has therefore concentrated on adsorption on to hydrophobic solids and gives an interesting account of kinetic and equilibrium aspects with some discussion of the correlation between adsorption and surfactant structure. However, in most practical cases the exact relationship between adsorption and soil removal remains obscure. In chap.8, Contact Angles and Wetting, J. A. Finch and G. W. Smith consider another complex process in which surfactant plays a key role. The authors give a general survey which avoids an in-depth discussion of wetting fundamentals and puts special emphasis on flotation2306 REVIEWS OF BOOKS processes. This is a useful review which provides a good introduction to the surface chemistry of mineral flotation. Overall the book is well produced, with a fairly good subject-index and adequate references. Were it not for its remarkably high price I would have no hesitation in recommending it unreservedly to anyone - student, research worker or technologist - needing a broad, authoritative and stimulating review of the physical chemistry of surfactant action. B. T. INGRAM Received 4th September, 198 1 The Chemistry of Living Systems.By R. F. STEINER and S. POMERANTZ. (Van Nostrand, New This is a refreshingly different approach from those presented by the majority of biochemical undergraduate texts. The authors have cast the net wider, to include topics such as nutrition, terpenes and steroids, hormonal regulation, and the properties of plasma and some specialized tissues. The more conventional subjects of biosynthesis, metabolism and genetics are treated in a manner that makes interesting reading, even to those whose bread and butter is the teaching of biochemistry. There is the usual problem posed by American undergraduate texts: where does it fit into the British University system? The book is intended as ‘a one-semester course in biochemistry at the junior or senior level, given in chemistry, biochemistry or biology departments for premedical, predental, preveterinary, health science or agronomy students, as well as for other nonchemistry majors.The book can be used most effectively by students with one year of basic chemistry and biology and at least one semester of organic chemistry. Although calculus notation appears in one chapter, its use is minimal and students lacking the knowledge of calculus will not be significantly impeded. ’ Actually calculus notation appears in two chapters (sedimentation and enzyme kinetics), but the above quotation emphasises the problems involved in recommending this book to a given group of students. It is based very much on the qualitative approach to the subject, with a minimum input from physical chemistry.Only eight pages are devoted to the properties of membranes, with no discussion of their physical properties. Membrane transport is disposed of in three pages. Protein crystallography does not extend beyond the Bragg equation, so that there is little indication how the diffractogram is used to arrive at the structure. Again, the discussion of native state energetics is simplistic. This is a pity, bearing in mind the advances made in the past few years. Perhaps a more thorough discussion of such topics was impossible because of the very superficial (4 pp.) treatment given to thermodynamics, in which entropy is disposed of in eight lines. Altogether, the emphasis given to various subjects is quite variable, and it is difficult to understand the underlying rationale. Thus, amino acid metabolism, nucleotide chemistry and carbohydrate metabolism are treated in some detail, whereas the significance of ATP and electron transport are disposed of in one page each.Sedimentation methods are treated in some detail, and one wonders what the average student is to make of fig. 5.10 with details of schlieren optics. Optical activity, on the other hand, gets short shrift; words like ‘azimuthal angle’, ‘electric vector’ and ‘chirality’ are introduced but not explained. In fairness to the authors one must admit that any division of emphasis in this vast subject could be questioned. This book has an underlying medical bias which is perhaps not too surprising. The overall production of the book is of a high standard, the exception being the quality of a few of the plate illustrations: the assembly of haemoglobin from its four subunits is hard to envisage from fig.17.9, and fig. 23.5 hardly shows up the polymerisations of fibrinogen. Apart from such minor blemishes, the book is well illustrated and each chapter contains a summary, a reading list and a set of review questions. This book can be recommended to the chemist who is unfamiliar with the chemical basis of biology and to those who teach biochemistry at a fairly elementary level. They will be sure to find new slants on a subject that hardly lacks adequate provision of textbooks. York, 1981). Pp. xii + 540. Price E21.20. F. FRANKS Received 19th August, 1981REVIEWS OF BOOKS 2307 Topics in Bioelectrochemistry and Bioenergetics, Volume 4.Ed. by G. MILAZZO. (John Wiley, The term ' Bioelectrochemistry ' has been coined to describe the application of electrochemical models and techniques to biological problems and, as a subject, it has been in vogue for about ten years. The list of biological phenomena which are electrochemical in nature is a long one and, in order to understand these complex processes, it is necessary that the biologist utilises the detailed and well characterised electrochemical principles. The problems of such utilisation are really two-fold : first, the biologist must be made aware of the fundamental electrochemical approaches and, secondly, the electrochemist must become aware of the basic biological processes that are amenable to study by his techniques.It is the established intention of bioelectrochemistry to overcome these two problems and this series of books provides one of the major routes for so doing. This volume contains six chapters, each written from an interdisciplinary approach, that describe a series of fundamental biological systems. Each chapter has been broken down into many short sections that describe one particular aspect of the system. Extensive use has been made of equations and simple figures and the editing is first class. The chapters are well set out, easy to follow and well referenced. Unfortunately, the choice of subject material seems somewhat random and there is no real overlap between the various chapters. This results in a series of one-off articles that do not facilitate a general introduction to this subject.Consequently, the series is more for specialists than for a general audience. The first chapter describes the physico-chemical aspects of homeostasis with particular reference to water and electrolyte balance in physiology. It is a well balanced article that makes extensive use of the physical chemistry laws and principles to explain this subject. Chapters on the principles of electric field effects in chemical and biological systems and on electron transferring proteins should be of considerable interest to electrochemists. Both chapters contain good background material and provide useful introductions into these topics. Similarly, the chapter on charge transport in lipid and biological membranes is relevant to many current research fields and makes interesting reading.The remaining chapters include descriptions of energy balance in red-blood-cell aggregation and electro-mechanical equilibrium in membranes. Overall, the book makes a useful contribution towards describing some of the techniques that are available for evaluating biological processes but the subject material is much less general than that provided in earlier volumes in this series. This is disappointing and in order to attract new researchers to this subject it is a trend that must be reversed. Let us hope that the next volume contains material of wider appeal. Chichester, 1981). Pp. xiv+342. Price &35. A. HARRIMAN Received 13th October, 1981 Interpenetrating Polymer Networks and Related Materials.By L. H. SPERLING. (Plenum Press, New York, 1981). Pp. xi+265. Price $35. This is a rather specialised book dealing with those particular examples of two component polymer systems which the author and several others have studied in great detail over the last ten to fifteen years. These materials consist of crosslinked polymers that share space with a separate phase of another polymer. The second polymer may also be crosslinked and one or both of the phases may be continuous throughout the sample. Many reviews have been published on this topic, and the author and others have contributed chapters to books dealing with the wider field of polymer blends. It is now considered that the subject has grown sufficiently to warrant a book dealing with it alone.I am of the opinion, however, that the subject is too limited to generate a very wide interest. The book is only short but nevertheless does go into rather more detail about specific pieces of research than is usually thought necessary. This is a direct consequence of the limited scope of the work. The first two chapters serve as a general introduction to polymer networks, and multicom-2308 REVIEWS OF BOOKS ponent polymer systems in general and interpenetrating networks (IPNs) in particular. The emphasis is placed on morphology and mechanical properties. Chap. 3 introduces a system of nomenclature for multicomponent polymer systems : blends, blocks, grafts and interpenetrating networks. It is logical but complicated. As an example is given the equation: which represents a physical blend of graft copolymers G,, and G23 where polymers I and I1 were blended first followed by the polymerisation of polymer 111 with grafting on to polymers I and 11.I doubt if the system will come into general use. Chap. 4 deals with ‘Homo-IPNs’, where a polymer network is formed within a preformed network of the same polymer by an intermediate swelling with monomer. These have been treated as model networks and attempts have been made to explain their mechanical properties in terms of rubber elasticity theory. The results are, however, not very conclusive. Chap. 5 discusses the different methods of synthesising IPNs, using specific examples in each case. The main methods are in situ polymerisation and co-coagulation of mixed latexes.Examples are given of both cases where both polymers are crosslinked and where only one is crosslinked (semi-IPNs). Related materials are also described, such as AB-crosslinked polymers where two polymers are grafted together to form one network and thermoplastic IPNs which utilise physical crosslinks. The latter could be of importance because the biggest drawback of IPNs as potential engineering materials is that, being permanently crosslinked, they must be manufactured in their final form. Chap. 6 and 7 deal with the physical properties of IPNs. The morphologies as determined by optical and electron microscopy are described and the modulus and loss properties explained in terms of them. One of the main factors is the extent of mixing of the two components. The tensile and impact strength are covered as well as other properties such as thermal degradation and barrier properties.The last chapter is titled ‘Actual or Proposed Applications’ and mostly discusses the patent literature on the subject. Much of this concerns standard material applications though part discusses more specialised applications such as dental materials, sound dampers, and grafting on to leather. In some cases the connection to the normal IPNs is a little tenuous. The book is well written and easy to read. It is well referenced, both numerically chapter by chapter and alphabetically at the end of the book. It is also quite well produced. Because of the great interest in multicomponent polymeric materials, in both industry and universities, it is possible that many will buy this book.I am, however, not convinced that they will get a lot more from it than is already available in the numerous reviews and book chapters devoted to this subject. D. J. WALSH Received 12th August, 1981 Chemistry and Physics of Carbon, Volume 17. Ed. by P. L. WALKER and P. A. THROWER. (Marcel Dekker, New York, 1981). Pp. xii+320. Price SFr 120. This well known series continues with four contributed articles. The first, by Lewis and Singer, clearly states the present position with regard to the development of e.s.r. responses during carbonization. The role of model compounds is evidently crucial to interpretation. Delhaes and Carmona then attempt to present and analyse data on non-crystalline compounds in terms of the Mott-CFO model of amorphous conductors and its lineal descendants.However, it is fair to say that at the present stage of development of theory, carbon presents too rich and varied a range of amorphous and semi-crystalline materials for any simple categorisation to be successful. To my mind, although this article is a valuable source of data, it is too ambitious in scope. No such criticisms can be made of the third article, a detailed investigation of the role of substitutional boron in the post-irradiation behaviour of graphite in so far as it can be separated from the radiation damage associated with the l0B(n, cc)’Li reaction. This is a subtle matter of some importance to materials scientists in the nuclear industry: the authors serve them well.REVIEWS OF BOOKS 2309 Finally, Moore essays to bring us up to date on Highly Oriented Pyrolytic Graphite.As one of the midwives present at the birth of this material in 1963, I was interested to read of the technical applications in X-ray and neutron monochromators, but at the same time must record my disappointment at Dr Moore’s account of the role of HOPG in preparing and characterising intercalation compounds, which seems to me to sidestep all the really interesting and challenging problems of this fascinating field. D. A. YOUNG Received 12th August, 1981 Light Scattering in Liquids and Macromolecular Solutions. Ed. by V. DEGIORGIO, M. CORTI and M. GIGLIO. (Plenum, New York, 1980). Pp. ix+295. Price $35. This volume contains the printed versions of lectures presented at a Workshop on Quasielastic Light Scattering held in May 1979.There is no discussion. The material is broadly divided into four groups : (i) Colloids and Polymer Solutions, to which the principal contributions are made by Pusey, Griiner and Lehmann, Hess, and Fijnaut among others; (ii) Micelles, Thin Films and Biological Macromolecules where one particularly notes papers by Langevin and Fijnaut ; (iii) Phase Transitions and Hydrodynamic Instabilities, in which attention is directed to Rayleigh-Benard instability and fluctuations at the surfaces of growing crystals, and finally section (iv) on Forced Rayleigh Scattering, for which one seeks to enhance the normal statistical fluctuations of temperature and density (concentration) by the application of coherent external stimuli. Some of the material in this book is well travelled and will already be familiar to colloid scientists interested in this general area.Although the book does serve a useful purpose in that it brings together some valuable papers which could otherwise only be found by a careful literature search covering some 10 or 15 journals, it is difficult to identify any particular groups to which purchase could be recommended. D. A. YOUNG Received 12th August, 1981 Problems of Biological Physics. By L. A. BLUMENFELD. (Springer, Berlin, 198 1). Pp. ix + 224. Price $35.40, DM60. This book is an unusual one. It is based on a course of lectures given to students and postgraduates of the Biophysical Department at Moscow University. It is meant for those who have a good background in physics as well as in biology.It is unusual because it is neither a textbook nor a systematic account of a field of science. In a sense, it is a personal choice by Blumenfeld of those areas in which he is interested and which he sees interlinked by the relationship between statistics and mechanics in biological systems. An introductory chapter discusses ‘What is Biophysics?’ and states the aim of the book. Blumenfeld here states his basic symbol of faith ‘The known laws of physics are quite sufficient for a complete description and understanding of the structure and functioning of all existing biological systems.’ (Whilst I understand his meaning and its refusal to accept mystical approaches to explain biological phenomena, I am not sure that one needs to be so vehement in the statement of faith as this to keep mysticism at bay.) The first chapter in the book deals with ‘The Ordering of Biological Structures.’ Blumenfeld argues that there does not exist any special high degree of ordering in biological systems. He suggests that the construction of a formal apparatus of information theory taking into account the quality of the information would be a major step in the development of theoretical biology. Other chapters deal with ‘ Non equilibrium Thermodynamics and Biological Physics ’, ‘The Statistical Physics of Biopolymers ’, ‘ Conformational and Configurational Changes of Biopolymers ’, ‘The Physics of Enzyme Catalysis ’, ‘The Physics of Intracellular Biological Systems’ and ‘The Physics of Intracellular Energy Transformation and Accumulation. ’23 10 REVIEWS OF BOOKS A few extracts may indicate the refreshing style of the author: P.14. ‘All talk about “the antientropic tendency” of biological evolution, about the unique ordering of living matter is based on a misunderstanding. According to thermodynamic criteria, the ordering of any biological system is not greater than that of a piece of rock having the same weight.‘ P. 94. ‘ First of all, a few words about one delusion that is quite common among biochemists. Many people think that there exist certain general theories of catalysis in chemistry, but the application of these theories to enzyme reactions is difficult due to the complicated nature of biochemical processes and biological catalysts. This erroneous point of view is founded on the biochemists‘ unjustified worship of the power of classical physical chemistry. Unfortunately, there is no such thing as a more or less consistent general theory of catalysis.’ P. 165. Careful consideration shows, however, that the physical principles of the coupling of energy-donating and energy-accepting reactions during substrate phosphorylation are as obscure as the corresponding principles for membrane phosphorylation. ’ P. 208. ‘The development of quantitative and semi-empirical theories, capable of playing the role which Van’t Hoffs approach plays in thermodynamics and Arrhenius’s approach in kinetics. represents one of the most important tasks of the science of biological physics. ’ The book was translated from the Russian into English by the author himself.In my view, this has helped us to sense the personality of the author. He says what he thinks and says it clearly. Where he sees trivia in thinking or errors of experiment, he states it. I find the book to be thought-provoking and worthy of much time and consideration. D. CHAPMAN Receiiied 9th Nowmber, 198 1 Progress in Reaction Kinetics, Volume 10. Ed. by K. R. JENNINCS and R. B. CUNDALL. (Pergamon Press, Oxford, 1981). Pp. 406. Price E36, $82.50. This volume is the latest in a series that has long provided a systematic and comprehensive review of progress in the study of reaction kinetics. It deals with three areas of modern research in which there is currently rapid progress and great interest : the dynamics of reactive collisions, the reactions of electronically excited atoms and the luminescent kinetics of metal complexes in solution.A most comprehensive review of the dynamics of reactive collisions covers all work in the field from its inception, in an encyclopaedic manner that should provide a very valuable source of reference. The review of the reactions of electronically excited states does not deal with individual reactions in quite so detailed a manner, but discusses the wide range of physical and chemical processes involved most lucidly and provides a comprehensive index of reactions as an appendix. The luminescent kinetics of metal complexes in solution are not amenable to study at the precise and detailed level which may be gained for gas-phase reactions. However, these processes are of great importance for the understanding of photosynthesis and photo- electrochemistry and are central to efforts to harness solar energy by chemical methods.The review of this area presents a clear picture of the progress made in this complex field and points to the most promising directions for future work. In all, this volume continues the tradition of authoritative and comprehensive reviews with which this series has become identified and will find an important place on the shelves of all chemistry libraries. Its rather high price may, however, deter many individual researchers. R. GRICE Received 20th October, 198 1 Studies in Surface Science and Catalysis, Volume 7, Parts A and B. New Horizons in Catalysis. Ed. by T. SEIYAMA and K. TANABE. (Elsevier, Amsterdam, and Kodansha, Tokyo, 1981).Pp. A xxx+751, B xvi+782. Price $170.75, Dfl 350. These two volumes form a complete record of the proceedings of the 7th International Congress on Catalysis held in Tokyo in early July 1980, the hosts being the Catalyst SocietyREVIEWS OF BOOKS 231 1 of Japan. Different countries are chosen for the venue of these four-yearly meetings; the present one is the first to be held in the Orient. Their pattern is now firmly established with five plenary lectures; two from the U.S.A., and one each from the U.S.S.R., Western Europe and the host country. Three were on specific topics: Molecular Shape Selective Catalysis (P. B. Weiss), Co-ordination Chemistry of Metal Surfaces and Metal Complexes (E. L. Muetterties) and Anchored Complexes in Catalytic Research (Yu.I. Yermakov); and two on more general themes: Surface Science and Catalysis (G. Ertl), and Elucidation of Mechanisms of Hetero- geneous Catalysis (E. Tamaru). All were most informative and of high standard. The separate publication of a paperback edition of these lectures at a modest price within the means of individual scientists would undoubtedly be most welcome. As with previous conferences, the attendance was about 1000, the number of papersjust over 100, these having being selected from three times the number originally submitted. As a consequence the standard of the papers was consistently high and the range of topics extensive. As in the London Congress of 1976 almost two-thirds of the contributions originated from four countries (U.S.A., France, Japan, U.K.), the main difference being that the Japanese share was twice as large and that of the U.K.was halved, reflecting the change of the host country. The U.S.S.R. contributed 8 papers on both occasions and the remainder were from around 20 different countries, mostly as single contributions. Surprisingly, less than 10% of authors of papers and active discussants at the U.K. Congress attended the Tokyo meeting, probably indicating the rapid progress of catalytic research. The present Congress had one new feature, a Communication session, comprising 64 short reports, each occupying two printed pages, giving the latest significant results of research still in progress. It was evidently a successful venture and will probably be preferred by many to the poster sessions.Much of the latest research work represented the extension and development of that discussed at the London Congress. Zeolitic catalysts were much in evidence: encaged transition metal complexes of Pt, Te, Ru, Rh and Ir, many as carbonyls, and zeolites with dispersed and exchanged metals were thoroughly and critically examined with respect to their activity and selectivity. Similarly, alloy catalysts (Pt/Ni, Pt/Cu, Pt/Sn, Pt/Au, Pt/Pd, Ru/ Fey Fe/Co, Co/Mo) and bimetallic clusters dispersed on various oxide supports, and metal-ion implanta- tion in single crystals (Pt/a-Al,O,) received considerable attention. An interesting development was the examination of the catalytic activity of non-equilibrium structures of metastable Pd/Si glasses and the contribution to our knowledge of molecular shape selectivity following the preparation of cross-linked smectites with lamellar spaces instead of intracrystalline channels of the Y-type zeolites.Work has been continued on the immobilization of enzymes by u-v. grafting of monomers to synthetic polymers and also on the heterogenisation of catalytically active homogeneous metal complexes by anchoring them to a substrate. The relationship to activity and selectivity of the distribution of particle size of dispersed metals has been studied by various techniques such as line-profiles by X-ray diffraction, E.S.C.A. and photo-electron spectroscopy. Other sophisticated methods included molecular-beam relaxation spectroscopy under steady-state conditions of the catalyst, extended X-ray absorption fine-structure analysis, X-ray photoelectron spectroscopy in combination with mass spectrometry as well as analytical electron-microscopy and transient isotope tracing.In addition to these more fundamental studies, one session was devoted to industrial technology of catalytic processes. The two volumes have been prepared by direct photo-reproduction of camera-ready typescript and the combined efforts of editors and publishers have resulted in an excellent presentation of both papers and discussion remarks, but the delay in final production of nearly 15 months is longer than expected. The price of $170.75 is rather forbidding, and catalytic chemists might well be gravely disappointed in not finding them in many university libraries that have suffered from severe reductions of the annual budgets, despite the importance of this publication. F. C. TOMPKINS Received 5th November, 198 12312 REVIEWS OF BOOKS Semiconducting Polymers. By M. KRYSZEWSKI. (PWN Polish Scientific Publishers, Warsaw, 1980). Pp. xv+710. Price $35. The study of the electrical properties of polymeric materials is an interdisciplinary subject with its roots in organic chemistry, polymer chemistry and solid-state physics, but with possible applications in electronics and biology. As the subject has developed the task of following the extensive literature has become a formidable one, not least because many papers appear in less readily available Eastern European and Russian journals. Professor Kryszewski’s book is a critical review of the more significant publications in the field. It consists of a series of essays on various aspects of the subject, written much in the style of the Specialist Periodical Reports of the Royal Society of Chemistry with relatively few diagrams and equations. The preparation and electrical, magnetic and catalytic properties all receive extensive coverage, as do the properties of biological polymers. The major developments since the publication of the Polish edition are covered by the substantial final chapter. Amongst the 3000 references to the original literature are many concerned with monomeric materials such as polycyclic hydrocarbons, dyestuffs and charge transfer complexes, whose study has played a large part in the development of theories of the 0rganic:solid state. The absence of formal development of theories and the assumption of a familiarity with both polymer chemistry and solid state physics means that this book will be of the greatest value to those already working in the field who will find therein an immense amount of information, and informed comment. It is probably the most comprehensive and up-to-date survey of research on semiconducting polymers, and a most useful contribution to the literature. M. R. WILLIS Received 15th October, 1981

ISSN:0300-9599    

DOI:10.1039/F19827802303

出版商:RSC    

年代:1982

数据来源: RSC