Order and dynamics of rod-like and banana-shaped liquid crystals by 2H NMR*
Valentina Domenici
Dipartimento di Chimica e Chimica Industriale, via Risorgimento 35, 56126 Pisa, Italy
Abstract: Deuterium NMR spectroscopy is a very powerful technique for studying partially or totally ordered systems, such as liquid crystals (LCs) and polymers. LCs represent a branch of the most general class of soft materials, with peculiar physical and chemical properties which attracted scientific attention for their potentiality for technological applications. From a chemical point of view, there are three aspects in which 2H NMR could provide significant insights: (i) the conformational and structural properties; (ii) the molecular dynamics and mobility; and (iii) the orientational order and aggregation/distribution of molecules in the different liquid-crystalline phases. In this work, some of the recent developments in this field are discussed, focusing on two main topics: (1) the molecular dynamics of the smectic liquid-crystalline phases formed by rod-like molecules and (2) the unusual orientational and dynamic properties of the new liquid-crystalline mesophases formed by banana-shaped molecules (BLCs).
Keywords: liquid crystals; nematic; ferroelectric; smectic; NMR; deuterium; molecular dynamics; orientational order; banana-shaped molecules.
*Pure Appl. Chem. 79, 1-65 (2007). A collection of invited, peer-reviewed articles by the winners of the 2006 IUPAC Prize for Young Chemists.