Chapter 17 - The Theory of Chirality Induction and Chirality Reduction in Biomolecules

Abstract

The chapter discusses two aspects of molecular chirality: chirality induction and chirality reduction. Both processes occur on the local as well as the global levels of molecules. Some of the fundamental interactions within the molecules have the power to extend the chiral influence of any small region throughout the entire molecule, and the ability of these interactions to induce chirality in remote parts of the molecule have important practical consequences, especially in large molecules. Although in the traditional viewpoint, molecular chirality is often considered to require some minimal molecular size, in reality, even single atomic neighborhoods, or even smaller, but positive volume parts of the electron density cloud may be chiral. Using the old concept of chiral carbon centers of organic chemistry, at least four different substituents about some carbon nucleus have been regarded as necessary for that type of chirality that, of course, implied at least four nuclei for that type of chiral entity. As molecular modeling has become more refined, and detailed electron density modeling and reliable quantum chemistry calculations have become more widely used, the focus has been narrowed and it has become increasingly possible and useful to consider the local features of chiral electron density clouds on a much smaller scale. Evidently, these clouds reflect all the chirality aspects of molecules, and even small parts of this cloud show evident chiral features in any chiral molecule.