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Über dieses Buch

Stereochemistry is the part of chemistry that relates observable prop­ erties of chemical compounds to the structure of their molecules, i. e. the relative spatial arrangement of their constituent atoms. In classical stereochemistry, the spatial arrangements relevant for interpreting and predicting a given chemical property are customarily described by geometric features/ symmetries in some suitably chosen rigid model of the molecule The solution of stereochemical problems involving single molecular species is the danain of the geometry based approaches, such as the methods of classical stereochemistry, molecular mechanics and quantum chemistry. The molecules of a pure chemical compound form generally an ensemble of molecular individuals that differ in geometry and energy. Thus it is generally impossible to represent a chemical compund adequately by the geo­ metry of a rigid molecular model. In modern stereochemistry it is often necessary to analyze molecular relation within ensembles and families of stereoisomers and permutation isomers, including molecules whose geometric features are changing with time. Accordingly, there is definitely a need for new types of ideas, concepts, theories and techniques that are usable beyond the scope of customary methodology. This is why the present text was written.

Inhaltsverzeichnis

Frontmatter

The Permutational Approach to Stereochemistry

Frontmatter

Chapter I. The Description of Molecular Structure

Abstract
The classical description of molecules is based on their empirical formula, constitution, configuration, and conformation. In this chapter, we shall briefly review these concepts and also that of chirality, as they are commonly understood. A discussion of some structural features of flexible molecules indicates that purely geometrically based concepts of configuration, conformation, and chirality so well as some currently used modifications of those concepts cannot be universally applied in a consistent manner. We then propose a unified conceptual framework for stereochemistry, including new definitions of stereoisomerism and chirality. These definitions are based on chemistry, rather than on geometric models, and have an unambiguous meaning for all molecules.
I. Ugi, J. Dugundij, R. Kopp, D. Marquarding

Chapter II. The Chemical Identity Group

Abstract
In this chapter, we describe the construction of the chemical identity group [1] as well as the racemate group for a given compound, and present some of the techniques that will be used in this book to represent and interpret stereochemistry.
I. Ugi, J. Dugundij, R. Kopp, D. Marquarding

Chapter III. The Asymmetric Carbon Atom Revisited

Abstract
In this chapter, we illustrate our general approach to stereochemical problems, and the use of the concepts developed in the previous chapter, by studying the asymmetric carbon atom [1]: we first determine its chemical identity group, and then find that the group is compatible with the usual tetrahedral valence skeleton. It will be pointed out that even in the case of this molecule, which can be represented by a simple geometric model, a purely geometric view of its stereochemical features has inherent logical difficulties, and that these difficulties disappear when the chemical identity viewpoint is adopted.
I. Ugi, J. Dugundij, R. Kopp, D. Marquarding

The Mathematical Theory of the Chemical Identity Group

Frontmatter

Chapter IV. Families of Permutation Isomers

Abstract
The molecules of a pure and uniform chemical compound X are all chemically identical; although they may differ in shape at a given time, they interconvert spontaneously under the observation conditions. In chemistry it is customary to represent the stereochemistry of X by drawing some projection formula of a representative “molecular situation” belonging to X.
I. Ugi, J. Dugundij, R. Kopp, D. Marquarding

Chapter V. Reaction Schemes

Abstract
Within the present conceptual framework, molecules with some indistinguishable ligands and ligand-preserving isomerization processes can both be treated in a similar manner by using the notion of a reaction scheme.
I. Ugi, J. Dugundij, R. Kopp, D. Marquarding

Chapter VI. Structure of the Chemical Identity Group

Abstract
In this Chapter we study the structure of the chemical identity group. This will enable us to choose subgroups that have clear-cut geometrical/ chemical meanings, and to express the chemical identity group as a semi-direct product of such subgroups, thereby simplifying its construction and use in calculations.
I. Ugi, J. Dugundij, R. Kopp, D. Marquarding

Application of the Theory of the Chemical Identity Group to Actual Current Stereochemical Problems

Frontmatter

Chapter VII. Examples, Illustrations and Applications

Abstract
In this Chapter we give some applications of the theory to actual stereochemical problems. We do not intend to present a comprehensive survey; our purpose is simply to show
(a)
how actual chemical problems are expressed in terms of the theory,
 
(b)
how the theory is used to treat those problems and
 
(c)
that the needed computations are straightforward.
 
I. Ugi, J. Dugundij, R. Kopp, D. Marquarding

Chapter VIII. A Unified Nomenclature and Chemical Documentation System

Abstract
It is obvious that in order to have efficient and reliable exchange of information, a system of chemical nomenclature and documentation must accurately describe and permit exact reconstruction of the essential features of molecules (including their stereochemical features) from the encoded information.
I. Ugi, J. Dugundij, R. Kopp, D. Marquarding

Backmatter

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