Conformational studies of bipyrimidine-based mesogens by combination of DFT calculations and temperature-dependent infrared studies


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Barszcz B., Bogucki A., Swietlik R., AKDAŞ KILIÇ H. , Camerel F., Roisnel T.

LIQUID CRYSTALS, vol.46, no.9, pp.1403-1414, 2019 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 46 Issue: 9
  • Publication Date: 2019
  • Doi Number: 10.1080/02678292.2019.1575990
  • Title of Journal : LIQUID CRYSTALS
  • Page Numbers: pp.1403-1414
  • Keywords: Bipyrimidine, liquid crystal, dihedral angle, temperature-dependent IR studies, DFT calculations, LIQUID, LUMINESCENCE, MODULATION

Abstract

Combination of DFT calculations and solid-state temperature-dependent infrared spectroscopy has confirmed that the central core of recently developed bipyrimidine-based mesogens is not flat, i.e. do not adopt a disc shape, inside the columnar liquid-crystalline phase. For this purpose, the intensities and the frequency shifts of the most sensitive C-N and C-C bands of the central bipyrimidine core have been studied as a function of the temperature and of the dihedral angle. The results support the reported packing model in which the molecules are interdigitated alternatively along their long axis and their short axis to form columns inside the mesophase.