Syntheses and mesomorphic properties of new oxygen-bridged dicopper complex homologous derived from azo-containing salicylaldimine Schiff base ligands

摘要

The synthesis, characterization and liquid crystal properties of a homologous series of new tridentate 5-((4-(n)alkoxyphenyl) azo)-N-(3-ydroxypropyl) salicylaldimine ligands (alkoxy = octloxy, decyloxy, dodecyloxy and tetradecyloxy) and their dicopper(II) complexes are reported. These ligands were prepared by the condensation of the 5-((4-(n)alkoxyphenyl)azo)salicylaldehydes homologous with 3-amino-1-propanol. The ligands and their dicopper complexes have been characterized by IR, H-1 NMR, mass spectroscopy and elemental analyzes. The liquid crystalline properties of the ligands and the related dicopper complexes were studied by differential scanning calorimetry (DSC) and by using a polarizing microscope equipped with a heating and cooling stage. None of the free ligands exhibit liquid crystalline behavior but all of the dicopper complexes demonstrate a smectic A mesophase.