The synthesis and spectroscopic characterization of alkoxy substituted 2,2?-azoquinoxaline and its palladium complex

Abstract

The synthesis and spectroscopic properties of 5,6-didodecyloxyquinoxaline-2-(1H)-one oxime, 2,2'-azobist[5,6-didodecyloxyquinoxaline] and the cyclopalladated complex di-mu-acetato-2,2'-azobis[5,6-didodecyloxyquinoxaline] dipalladium(II) are reported. The novel compounds were characterized by elemental analysis, FT-IR spectroscopy, H-1 NMR spectroscopy, UV-vis spectroscopy and mass spectrometry. 5,6-Didodecyloxyquinoxaline-2-(1H)-one oxime exhibited liquid crystalline properties, as determined using differential scanning calorimetry, optical polarizing microscopy and X-ray investigation. The compound displayed a discotic mesophase over a large temperature interval that included room temperature. X-ray diffraction revealed that this compound forms a discotic hexagonal ordered columnar mesophase (col(ho)) and thus, has potential use as a colored liquid crystal. (c) 2007 Elsevier Ltd. All rights reserved.