Historical Development of the Subject

There is great current interest in the use of combinatorial methods, or high throughput experimentation (in which a large number of experiments are performed to explore the different effects of many variables), to prepare new 

Schematic representation of the pore size ranges of microporous and mesoporous solids. Whereas crystalline materials have well-defined pore dimensions, those solids without atomic order on the long range (particularly the mesoporous solids) can be prepared with pore sizes that can vary widely, depending on synthetic and post-synthetic treatment conditions. 

Under favourable geological conditions significant deposits of useful natural zeolites (such as clinoptililite and mordenite) have resulted and are mined and used in large quantities. More often, and certainly for many of the most important commercial zeolites, mineral forms of the zeolite types only occur in minute quantities. Very small amounts of natural analogues to the widely used zeolites Y, ZSM-5 and Beta have all been found, and are known as faujasite. 

By the 1980s most of the aluminosilicate zeolites currently used industrially were known, and the emphasis shifted to the study of these materials using a range of powerful new techniques that came of age at this time. These included, in particular, solid state NMR, X-ray and neutron powder diffraction analysis, high resolution electron microscopy and computational methods. All were ideal for the study of structural details of solids that were rarely available, and never used in industrial applications, other than as microcrystalline powders. All these techniques are applicable to the bulk of the solid - this in turn makes up the (internal) surface, which is accessible to adsorbed molecules. Since the techniques are able to operate under any conditions of gas pressure, they may be used to extract structural details in situ under the operating conditions of ion exchange, adsorption and catalysis. In particular, zeolitic systems have proved ideal for the study, understanding and subsequent improvement of solid acid catalysts. 

Already by 1980 it was known that molecular sieve frameworks of compositions other than aluminosilicate could be prepared. Pure silica polymorphs of ZSM-5 and ZSM-11, for example, (patented as silicalite-1 and silicalite-2) were of interest because their internal surfaces were hydrophobic rather than 

---

It is also important to realize that chemistry is not a static body of knowledge as defined by the contents of a textbook. Chemistry came from somewhere and is at present heading in various specific directions. It is a living self-stimulating discipline, and we have tried to transmit this sense of growth and excitement by reference to the historical development of the subject when appropriate. The chemistry of the elements is presented in a logical and academically consistent way but is interspersed with additional material which illuminates, exemplifies, extends or otherwise enhances the chemistry being discussed. 

General accounts of prototropic tautomerism have been presented by Ingold and Baker" these include an outline of the historical development of the subject in which heteroaromatic compounds are discussed incidentally, and, therefore, such a historical account will not be given here. Of historical interest are Eistert s book on tautomerism and mesomerism which was published in 1938, a review on — NH-CO— tautomerism by Arndt and Eistert published in 1938, and Heller s account of heterocyclic tautomerism which appeared in 1925. Although more recent works on heterocyclic chemistry (e.g., references 9-11) have dealt incidentally with tautomerism, no unified... 

In order to understand the principles involved in electron-transfer catalysis and also in order to appreciate the historical development of the subject, we must treat hole catalysis and electron transfer between metal atoms and ions and organic substrates before examining catalytic reactions in more detail. This review is intended to cover the basic principles involved in these three areas and to provide a conceptual framework for electron-transfer catalysis. 

I have felt that in writing on this complex subject my primary duty hould be to present the theory of the chemical bond (from my point of view) in as straightforward a way as possible, relegating the historical development of the subject to a secondary place Many references are included to early work in this field the papers on the electronic theory of valence published during the last twenty years are so numerous, however, and often represent such small differences of opinion as to make the discussion of all of them unnecessary and even undesirable. 

The hydrolysis and formation of esters in solutions of strong acids show very varied behaviour, and depend on a rather large number of different factors. Our understanding of the quantitative behaviour of these reactions has become much clearer in recent years, and since an attempt to follow the historical development of the subject might obscure parts of the pattern that has emerged, it seems best to base a discussion on recent results. 

A symposium in print, Physical Organic Chemistry for the 21st Century, has appeared under the auspices of IUPAC Commission III.2.439 Some twenty distinguished authors or groups of authors have tried to foresee the way in which the various parts of the subject may develop in the next decade or so. Tidwell has provided a prologue on the first century of physical organic chemistry and many of the articles reflect on the historical development of the subject. 

Within the format of this contribution, only a brief outline of ftie vast range of P-donor ligand architecture can be given. Most of the examples given are based upon P-C bonding, which reflects flie historical development of the subject. 

In this review it is hoped to give some idea of the historical development of the subject as well as of its present status, and the elucidation of the pathway for the conversion of phenylalanine and tyrosine to acetoacetate is therefore set out in a manner corresponding in some degree to the development of knowledge on the subject. 

Although the reaction of acetic anhydride in the presence of an acid catalyst with carbohydrates of all classes, and their derivatives, has been studied for some ninety years, no survey on the topic has been written in this Series. The present brief article does not attempt to give a full historical development of the subject (particularly for polysaccharides), but it attempts to bring together in one place an account of the reactions possible with the reagents. Thus, the uses of reactions are stressed, rather than the mechanistic interpretations of them. Some aspects of this topic have been discussed in other articles in this Series, and mention of them will be made where appropriate. 

Mammalian tendons are readily available and provide the best degree of fibrillar orientation. Patterns obtained from them (Figs. 3 and 7) permit observation of the maximum number of diffractions. Instead of tracing the historical development of the subject, this discussion is based on data obtained from the best patterns available to the author. Table IV shows the average measurements for the positions of individual spot... 

Numerous friends and colleagues in the field of metathesis (the soldiers to whom we dedicate this book) have encouraged us to believe that a new book incorporating these recent developments would be both timely and welcome. We felt, however, that the book should still outline the historical development of the subject and not just be a supplement to the original book. This has necessarily meant some compression of earlier material and some restriction of discussion. The title has been expanded to include the words Metathesis Polymerization , which embraces not only ring-opening metathesis polymerization (ROMP), but also the metathesis condensation reactions of acyclic dienes (ADMET) and the addition reactions of acetylenes. The division of the material and the subjects of the chapters follow the same pattern as before. The literature has been covered up to mid-1996. 

For an account of the historical development of the subject, see R. P. Bell, Acid-Base Catalysis, Oxford, 1941. 

This Report is concerned with the surface heterogeneity of gas-solid and liquid-solid systems. It presents a historical development of the subject with particular emphasis placed on work published in the period 1970 to July 1981. 

Current interest in the study of adipose tissue metabolism has been stimulated by the work of many researchers in various countries. It is not my purpose to give a full account of the historical development of the subject, but a few highlights should be mentioned. Among these (a) the demonstration of the rapid turnover of stored fat " (b) the publication in 1948 of the classic review on the physiology of adipose tissue by Wertheimer and Shapiro (c) the identification of the plasma free fatty acids (FFA) as the form in which the triglycerides stored in the adipose tissue are mobilized and made available as fuel to the body tissues, - and the introduction of the concept of caloric homeostasis . ... 

Contemporary discussion of the fundamentals of adhesion generally reflects the historical development of the subject. For convenience, this approach will be adopted here. Early work in the 1920s discussed two kinds of adhesion. Where surfaces were smooth, what would now be described as adsorption theory applied, with rough or porous surfaces mechanical theory. The next two sections, Sects. 2.2 and 2.3, of this chapter discuss these in turn. 

Finally, it only remains in this section, concerned with the historical development of the subject, to point out that a number of reviews have appeared dealing with the earlier work in the field. ... 

---