Chirality in chemistry

Chirality (handedness) is older than life on tliis planet. Still it was not until 1848 when Pasteur manually separated enantiomeric crystals that chirality in chemistry was first appreciated ". The independent work of Van t Hoff and Le Bel revealed the molecirlar origin behind this phenomenon. 

Vladimir Prelog, Chirality in Chemistry. in Nobel Lectures Chemistry 1971-1980. World Scientific, Singapore, 1993, pp. 200-216. 

In chemistry, chiral is a term used to describe asymmetric molecules Ibat arc tnirror-images of each other, i,e ihey are related to each other optically as right and left hands. Such molecules are also called enantiomers and arc characterized by optical activity, An excellent summary of chirality in chemistry is given by Prelog. Science, 193, 17-24 1197(h). 

Since Pasteur s time, stereochemistry has experienced an enormous intellectual growth and has also found widespread industrial application. In recent years, a spate of articles, reviews, books, and international conferences and symposia have dealt with the role of chirality in chemistry, and three new journals have been specifically devoted to this topic Chirality, by Wiley-Liss in 1989, Tetrahedron Asymmetry, by Pergamon Press in 1990, and Enantiomer, by Gordon and Breach in 1996. Much of the research reported in these media, though motivated to some degree by market forces—notably by the demand of pharmaceutical industry for enantiopure drugs4—serves as a reminder that molecular chirality remains the centerpiece of stereochemistry and allied branches of science. 

The concept of symmetry and chirality in chemistry has a well-defined meaning only in relation to experiment.18 Consider a system of one or more molecules subject to experimental observation. The properties of any such system are invariant with respect to its symmetry operations.42 In Pierre Curie s famous dictum, c est la dissymetrie qui cree le phenomfcne. 43 That is, a phenomenon is expected to exist—and can in principle be observed—only because certain elements of symmetry are absent from the system. It follows that all manifestations of chirality flow from a single source the absence of symmetry elements of the second kind in the group describing the system under observation. Accordingly, if... 

The topological chirality or achirality of a molecule thus refers exclusively to its molecular graph, and not necessarily to a physically realistic model. Yet, as remarked above, the concept of chirality in chemistry has a well-defined meaning... 

V. Prelog, Chirality in Chemistry (Nobel lecture). Science 1976,193,17-24. 

Chirality has been an area of enormous interest and significance for chemists. The identification of an enantiomeric excess in some amino acids found in a meteorite (Science 1997, pp. 275, 951) has generated a lot of excitement among chemists because chirality even figures in discussions of the origin of life. Robin Le Poidevin, in the chapter "Space and the Chiral Molecule," provides an instance of a reciprocally beneficial relationship between chemistry and philosophy. He examines some implications of the phenomenon of chirality in chemistry—optical isomerism in particular—for standard philosophical positions about space. At the same time, he shows how an understanding of "spatial realism" allows us to better appreciate the often subtle differences between different kinds of isomerism. 

Chirality in chemistry is associated with 3D molecular forms. It is a consequence of the asymmetrical substitution of tetrahedral carbons. However, at the beginning of this century Kelvin had defined chirality for objects in/i-dimensional spaces. Chiral... 

Prelog V (1975) Chirality in chemistry. In Les prix Nobel 1975, Nobel Lectures... 

Chiroptical Properties. Professor Prelog s 1975 Nobel lecture on Chirality in Chemistry has been published. This, along with a general review on discriminating interactions between chiral molecules, provides a general basis for considering the wider consequences of molecular asymmetry. 

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