The Infrared and Raman Spectra of p-Azoxyanisole in the Crystalline, Nematic and Isotropic Liquid Phases

Abstract

Abstract The infrared and Raman spectra of p-azoxyanisole were measured in the crystalline, nematic, and isotropic liquid phases. In the internal vibrational region, abrupt changes in intensity were observed at the crystalline-nematic phase transition; however, no appreciable change was detected at the nematic-isotropic liquid phase transition. In the external vibrational region, some of the Raman lattice bands, which eventually vanish in the isotropic liquid phase, persist in the nematic phase, while some of the infrared lattice bands disappear and a new band appears as the crystalline-nematic phase transition point is reached and traversed. The assignments of the infrared and Raman bands which appear or disappear in the nematic phase are discussed.