Some New Properties of Chiral Molecules

[摘要] The work in this thesis divides naturally into two distinct parts which are linked by the general underlying theme of chiral discrimination. The first part concerns the discriminatory response of chiral molecules to circularly polarized light which constitutes optical activity, the second, chiral discrimination in intermolecular forces. Specifically, in Part I, a detailed study of rotational optical activity is undertaken. Expressions are derived to describe Raman optical activity, optical rotation and circular dichroism by first treating the simple case of a symmetric top molecule and then allowing this to be the basis for the more sophisticated development required for an asymmetric top molecule. In Part II, discrimination in the dispersion interaction between odd-electron chiral molecules is studied. It is shown that novel contributions to the discriminatory interaction are introduced by allowing for the time-odd part of the molecular optical activity tensor which is supported by chiral molecular systems in which there is some source of time asymmetry, as provided, for example, by the residual electronic angular momenta of odd-electron molecules. Both a semi-classical and a quantum electrodynamical treatment are given, the latter making possible a study of the wave-zone region in which the finite speed of light must be taken into account. Calculations, within the semi-classical model, on a hypothetical odd-electron chiral transition metal complex of 0* symmetry indicate that the new discriminatory contributions could be within an order of magnitude of the conventional discriminatory contributions.

[发布机构] University:University of Glasgow

[关键词] Organic chemistry, Molecular chemistry