Conformational Studies in Organic Liquids

Abstract

The conformational behaviour of organic molecules displays a large variation, depending on multiple factors. Some of these are intramolecular, such as types and number of bonds, steric hindrance, presence of heteroatoms, degree of coupling between internal rotors. Others correspond to intermolecular effects and depend on the nature and magnitude of interactions. In this lecture, a number of conformational studies on various types of organic molecules (ethylamine, n-propylamine, n-butane, benzyl chloride and benzal chloride) is considered. Various spectroscopic techniques (Raman, infrared, NMR, high-resolution gas-phase absorption) and different computational methods (ab initio MO calculations, normal mode analysis) are considered in a complementary way. For some of the experimental techniques, temperature and solvent variation enable to vary populations of conformational states and to modulate some of the important interactions. In addition, consideration of different analogues of the studied molecules, enable to assess important structural variations.