The free porphyrin 2,3,7,8,12,13,17,18-octakis(octylthio)tetraazaporphyrin (H2P8) and its copper(II) complex (CuP8) have been synthesized and studied by UV-VIS spectroscopy, calorimetric and X-ray analysis. The calorimetric analysis, as well the optical observations, indicate for CuP8 the existence of a liquid-crystalline mesophase between 67.6 and 151.7-degrees-C. The mesophase is characterized by X-ray diffraction at 81-degrees-C as discotic with an hexagonal arrangement of the columns. The stacking periodicity along the axes of the columns is almost-equal-to 4.1 angstrom, with a tilt angle of molecular planes estimated to be about 30-degrees.
DOPPELT, PASCAL;HUILLE, SYLVAIN, NEW J. CHEM., 14,(1990) N-9, C. 607-609