Synthesis and characterization of 1,4-phenylenediamine derivatives containing hydroxyl and cyclotriphosphazene as terminal group

Abstract

A series of compounds with two Schiff base linking units and four different substituents (heptyl, dodecyl, methoxy and chloro) have been successfully synthesized. Further reactions form new monosubstituted cyclotriphosphazene based molecules with different substituents. These compounds were characterized using FT-IR (Fourier Transform Infrared), NMR (Nuclear Magnetic Resonance) and CHN elemental analysis. The transition mesophase(s) of these compounds were determined using POM (Polarized Optical Microscope) and DSC (Differential Scanning Calorimetry). Two compounds with heptyl and dodecyl substituents were found to be mesogenic with smectic C phases while monosubstituted cyclotriphosphazene compounds of the same substituents (heptyl and dodecyl chains) were also found to be mesogenic. Cyclotriphosphazene compounds with heptyl chain shows smectic C and nematic phases while compound with dodecyl chain shows only the nematic phase. However, compounds with methoxy and chloro substituents were found to be non-mesogenic.