Preparation and thermal properties of the bis[5-((4-heptyl oxyphenyl)azo)-N-(4-alkoxyphenyl)-salicylaldiminato]copper(II) complex homologues

A series of 5-((4-heptyloxyphenyl)azo)-N-(4-alkoxyphenyl)-salicylaldimine and bis[5-((4-heptyloxyphenyl)azo)-N-(4-alkoxy-phenyl)-salicylaldiminato]copper(II) complex homologues (alkoxy = (OCmH2m+1)-C-n; m = 3-7) have been synthesized and characterized by elemental analyses, IR and NMR spectroscopy. The thermal behavior of these homologous compounds was examined by differential scanning calorimetry (DSC), polarizing microscopic observations and powder X-ray diffraction. The complex homologues cases of m = 3 and 5 exhibit solid polymorphism but for m = 6 a monotropic S-A liquid crystalline phase on cooling from isotropic liquid is seen. (C) 1998 Elsevier Science Ltd. All rights reserved.