Induced Smectic-G Phase through Intermolecular Hydrogen Bonding Part VIII: Phase and Crystallization Behaviours of 2-(p-n-heptyloxybenzylidene imino)-5-chloro-pyridine: P-n-alkoxybenzoic acid (HICPrwABA) Complexes

Abstract

New intermolecular H-bonded liquid crystalline complexes, viz., 2-(p-n-heptyloxybenzylidene imino)-5-chloro-pyridine:p-/z-alkoxybenzoic acid; (HICP:nABA) (where n denotes the alkoxy carbon numbers 3 to 10 and 12) exhibiting smectic-F (n = 12) and smectic-G phases have been synthesized and characterized by Thermal Microscopy and Differential Scanning Calorimetry (DSC). Detailed IR (solid and solution states) analysis confirms the existence of intermolecular H-bonding between the pyridyl nitrogen and the COOH group of the p-n-alkoxybenzoic acid moiety. The phase behaviour of the series is discussed in the light of reported data on free p-n-alkoxybenzoic acids. The crystallization kinetics of a representative complex, using the DSC technique, is discussed. The mechanism of the crystal growth of the new crystalline smectic-G phase is computed with the Avrami equation. © 2014, Verlag der Zeitschrift für Naturforschung. All rights reserved.