Spectroscopic investigation of local molecular dynamics in liquid crystals I. Small molecules

Abstract
The dynamics of liquid crystal systems, consisting of either small molecules or polymer chains with main-chain or side-chain mesogenic groups, can be investigated using the same spectroscopic techniques which are applied to isotropic systems. This article briefly reviews 1H, 13C and 2H N.M.R. and E.S.R. spectroscopy as well as dielectric relaxation. The particular features related to the oriented nature of the liquid crystal phases are developed. Typical examples of studies performed on small-molecule liquid crystals using these various spectroscopic techniques are described.