Liquid Crystalline Properties of Unsymmetrical N-(o-hydroxybenzylidene)-N′-(4-n-alkoxybenzoyloxybenzylidene)azines: Synthesis and Characterization

Abstract

A new series of mesogenic unsymmetrical azines, N-(o-hydroxybenzylidene)-N 0 -(4-n-alkoxybenzoyloxybenzylidene)azines, HOC 6 H 4 CH=N-N=CHC 6 H 4 OCOC 6 H 4 O C m H 2m þ 1 (m ¼ 7, 8, 9, 10, 11, 12, 14, and 16) have been prepared. They have been characterized by elemental analyses, FT-IR, UV-visible, 1 H, and 13 C NMR (Nuclear Magnetic Resonance) spectra. The mesomorphic properties of these compounds were investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The azines m ¼ 7, 10, and 14 exhibit features of enantiotropic nematic (N) mesophase whereas azines m ¼ 8, 11 exhibit features of a monotropic nematic phase. The azines m ¼ 9, 12, and 16 do not exhibit mesogenic nature.

Synthesis of Ferrocenyl-Based Unsymmetrical Azines via a Simple Reaction of Aldehydes with Ketone-Derived N-Tosyl Hydrazones and the Evaluation of the Extent of Conjugation in the Molecule

“…Azines are one of a number of very important compounds that have interesting chemical properties. Among their useful properties, azines have attracted great interest due to their potential in biological properties, in the design of liquid crystals, − and in other materials applications. − Molina’s and our group reported the application of azines as a recognition unit in chemosensors, , which had high selectivity toward Hg 2+ or Cu 2+ ions. Moreover, our group demonstrated that 1-substituted ferrocene-based unsymmetrical azines that have different substituent groups on the phenyl have significant influence on the sensitivity.…”