Molecular structural changes at the phase transitions in thermotropic liquid crystals: A spectroscopic study of 4-dodecyloxy-4′-cyano biphenyl

Abstract

The analysis of the vibrational infrared and Raman spectra of 4-dodecyloxy-4′-cyano biphenyl (12-OCB) reveals characteristic structural markers which describe the evolution of the molecular structure through K–SA and SA–I phase transition. The conformational collapse of the dodecyloxy residue into a ‘‘liquid-like’’ structure unquestionably occurs at K–SA transition. A rearrangement of the conformation of the biphenyl residue is also observed.