Subject historical perspective

Subsequent chapters deal largely with developments in the theory of geometric phase and non-adiabatic coupling over the past 10 years, but the editors agreed with me that there would be some value in including a chapter on early contributions to the field, to provide a historical perspective. No doubt the choice of material will seem subjective to some. Others will find it redundant to repeat well-established results in an Advances volume, but this chapter is not... 

We will start this review by considering the crystallization within isolated MD structures and its consequences for the nucleation phenomena. This is a subject that has been presented in a previous review [44], but where very recent works have made an important impact in its understanding, we feel that a unifying picture from a historical perspective is needed. 

The availability of isotopes has made it possible to complete the descriptions of the steric course of most of the individual reactions of carbohydrate metabolism and steroid metabolism and many of the reactions of fat and amino acid metabolism. The subject has been covered from various angles in several chapters of the third edition of the Enzymes, particularly in the one by Popjack b, in a comprehensive treatise 2>3>, and in numerous recent reviews 4 12>. The wealth of available detail defies any attempt to be complete. I will try, rather, to describe trends in current experimentation, and to fit these trends into historical perspective. In so doing, I will select examples rather arbitrarily, entirely out of my own interests, and I beg the reader s indulgence for this bias. 

Third, we will add brief historical perspectives to the subject so that students can see the context fi-om which ideas arose in the development of modem technology. Further, since the job markets in chemical engineering are changing rapidly, the student may perhaps also be able to see from its history where chemical reaction engineering might be heading and the causes and steps by which it has evolved and will continue to evolve. 

It does not provide much historical perspective on the development of quantum mechanics. Subjects such as the photoelectric effect, black-body radiation, the dual nature of electrons and photons, and the Davisson and Germer experiments are not even discussed. 

Dioxetanes have been the sole subject of several specialized reviews in recent years (Bartlett and Landis, 1979 Horn et al., 1978-79 Adam, 1977 T. Wilson, 1976 Turro et al., 1974a Mumford, 1975). These articles cover with depth which is not possible here such topics as (1) preparation, (2) physical and spectroscopic characterization, (3) experimental techniques, especially for the study of chemiluminescence, (4) mechanisms of decomposition and chemiexcitation, (5) ground state transformations, and (6) reactions involving dioxetanes as postulated intermediates. The interested reader is referred to these articles for details on these specialized topics, and for some interesting historical perspectives. 

Organometallic chemistry has witnessed an exponential growth in the past half decade, and today is represented at its frontiers by the second edition of a multivolume text, two major journals and a plethora of monographs. Helmut Werner, a pioneer who has contributed extensively to the field, now offers us a personal view of important areas of transition metal chemistry. It is unusual in that it provides an historical perspective on some of the more significant developments in this area. He writes both with a great generosity of spirit and an obvious love of the subject. It is evident that both for him, and now his readers, it is not only the science, but also its protagonists, that are the focus of much attention. 

By now, nearly every chemist has had some introduction to the subject of supercritical extraction in one form or another, and it would seem that after scores of papers, newsreleases, and trade journal articles, only so much can be said about the background and early findings, the thermodynamic interactions between dissolved solutes and high pressure gases, the equations of state that can correlate and predict solubility behavior, the many applications of the technology (some of which are in flavors), the full scale coffee and hops extraction plants now in operation, etc. What, then, can a paper entitled "Supercritical Fluids - Overview and Specific Examples in Flavors Applications" give that s new -hopefully, a different development of the historical perspective... 

It is not our intention to present an exhaustive review of this important subject. Up-to-date reviews are provided elsewhere [38,37]. The classic review by Garten and Weiss [41 ] offers an excellent historical perspective. We do need to summarize here the issues that are essential for understanding the aqueous-phase adsorption phenomena. The main features of carbon surface chemistry are presented first and the con.sequent acid/base behavior of carbons is briefly discus.sed to illustrate their amphoteric character. In Section III it is shown that these phenomena often govern the adsorption of most inorganic compounds. In Section IV we argue that these phenomena can be dominant in the adsorption of organic compounds as well, but they are more often only a part of the whole story. 

The computationally viable description of electron correlation for stationary state molecular systems has been the subject of considerable research in the past two decades. A recent review1 gives a historical perspective on the developments in the field of quantum chemistry. The predominant methods for the description of electron correlation have been configuration interactions (Cl) and perturbation theory (PT) more recently, the variant of Cl involving reoptimization of the molecular orbitals [i.e., multiconfiguration self-consistent field (MCSCF)] has received much attention.1 As is reasonable to expect, neither Cl nor PT is wholly satisfactory a possible alternative is the use of cluster operators, in the electron excitations, to describe the correlation.2-3... 

Back in 1992, two of us (DWB and DO H) edited the first edition of Inorganic Materials in response to the growing emphasis and interest in materials chemistry. The second edition, which contained updated chapters, appeared in 1996 and was reprinted in paperback. The aim had always been to provide the reader with chapters that while not necessarily comprehensive, nonetheless gave a first-rate and well-referenced introduction to the subject for the first-time reader. As such, the target audience was from first-year postgraduate student upwards. Authors were carefully selected who were experts in their field and actively researching their topic, so were able to provide an up-to-date review of key aspects of a particular subject, whilst providing some historical perspective. In these two editions, we believe our authors achieved this admirably. 

The chemistry of sugar isothiocyanates and their reactions has been the subject of a specialized article in this series by Witczak4 in 1986 with 143 references dating up to 1984. The reader is also referred to the earlier work of Goodman5 on ureido sugars for a thorough historical perspective. It should... 

This report describes progress made on the application of many-body perturbation theory to the problem of molecular structure in recent years. However, since it is almost two decades since the last report51 on this subject in Specialist Periodical Reports, the opportunity will be taken to provide some historical perspective on the developments during the past two decades. 

The history of liquid chromatography and the influence of its pioneers have been the subject of several learned reviews (Sakodynskii, 1970 Kirchner, 1973 Ettre and Horvath, 1975). Indeed, the manner in which scientific attitudes and the turbulent history of Europe in the early decades of this century influenced the establishment of chromatography as a science would in itself be worthy of a textbook. In a book of this nature a detailed historical narrative would not be relevant but it is instructive to put the current state of the art of liquid chromatography within a historical perspective to provide the reader with a reahsation of the explosive development of chromatographic science within the past fifteen years. 

Very extensive computations have been carried out on the dynamics of reactions of the type A+BC. They are either founded on classical or on quantum mechanics, are either to be considered exact or involving more or less drastic approximations and have been based either in the real three dimensional world or in somewhat artificial spaces of lower dimensionality. These computations are thus attempts to solve the three-body problem more or less accurately. Other Chapters in this book extensively review this subject [41]. The papers, presented at a meeting celebrating "Fifty Years of Chemical Dynamics", held in Berlin in 1982 and published as an issue of the Berichte der Bunsen Gesellschaft in 1982, should be consulted, also for providing a historical perspective [42],... 

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