Details

Autor(en) / Beteiligte

• Murthy, A. V. S. N. Krishna
• Chalapathy, P. V.
• Srinivasulu, M.
• Madhumohan, M. L. N.
• Rao, Y. V.
• Potukuchi, D. M.

Titel

Influence of flexible chain, polar substitution and hydrogen bonding on phase stability in Shiff based (4)PyBD(4I)BrA-nOBA series of liquid crystals

Ist Teil von

• Molecular Crystals and Liquid Crystals, 2018-03, Vol.664 (1), p.46-68

Ort / Verlag

Philadelphia: Taylor & Francis

Erscheinungsjahr

2018

Quelle

Duke University Press journals

Beschreibungen/Notizen

• Shiff based Linear Hydrogen Bonded Liquid Crystalline homologues, viz., (4)PyBD(4 I )BrA-nOBAs for n = 2,3,4,5,6,7,8,10,11 and 12 are synthesized. 1 H-NMR and 13 C-NMR studies confirm the formation of HBLC and IR confirms the linear hydrogen bonding. Liquid crystal phase abundance, transition temperatures, enthalpy and order of transition are investigated by Polarized Optical Microscopy textural studies and Differential Scanning Calorimetry. Nematic, Smectic-A, -D, -C, B hexatic , -B Crystal , -F, -I and -G phases are identified. Large LC phase variances, viz., NAB hex FG and NACFG are exhibited by intermediate chain length with n = 5 and 6. A-C transition exhibited unique II-order nature. II-order nature for G-Solid transition explained. Phase diagram drawn with flexible chain length infers INA, and ACF and CIF MultiCritical Points and Lifshitz behaviour. NA TriCiritical Point predicted in [3+7] binary. Influences of chain length, linear HB and end polar(-Br) substitution for LC phase stability are is discussed. Results of Phase stability are discussed in the wake of the body of the data and reports in other LCs. DSC enthalpy suggests for utility of intermediate and higher homologues for device savvy tilted Smectic LC phases.