Conformational distribution of a ferroelectric liquid crystal revealed using fingerprint vibrational spectroscopy and the density functional theory

Abstract

The authors have investigated the conformational structure of the ferroelectric liquid crystal compound 4-3-methyl-2-chloropentanoyloxy- 4? -hexyloxy-biphenyl also known under the abbreviations 3M2CPHOB and C6 using vibrational (IR and Raman) spectroscopy. The measured spectra exhibit two bands corresponding to the CO stretching vibration that are separated by 20 cm-1. In contrast, the molecular structure comprises only one such group. They assigned the two bands to different conformers that coexist in a temperature range between 25 and 65 ?C covering the entire mesophase of this material. This assignment is strongly confirmed by calculated vibrational spectra based on the density functional theory.