@ppgfis_ufc_br

A combined experimental and theoretical approach to study SmC -> N-cybc phase transition in a four-ring bent-core liquid crystal

, , , , , , , , , and . NEW JOURNAL OF CHEMISTRY, 40 (8): 6834-6847 (2016)
DOI: 10.1039/c6nj00892e

Abstract

A newly synthesized four-ring bent-core liquid crystal (BCLC) has been studied using experimental and quantum chemical approach. Differential scanning calorimetry (DSC), polarised optical microscopy (POM), and X-ray investigations were carried out to identify the phase transitions and associated phases. DSC along with POM revealed four phase transitions i.e. Cr -> SmX -> SmC -> N-cybc -> Iso in the temperature range from 30 degrees C to 180 degrees C. The existence of smectic C like fluctuations also known as cybotactic groups in the broad temperature range of the nematic phase was confirmed by small angle X-ray diffraction. Conformational and vibrational analyses have been performed using density functional theory (DFT), to identify the most stable conformer having a bent shape. Analysis of the potential energy surface (PES) for different torsional angles revealed the most probable conformational states for the BCLC. Temperature dependent Fourier transform infrared (TD-FTIR) spectroscopy is used to study phase transitions and revealed marked changes in the spectral tine shape especially the vibrations of OH, CH2, CH3

Links and resources

Tags