CRYSTAL PHASE AND THERMAL TRANSFORMATION OF OXOTITANIUM PHTHALOCYANINES

The oxotitanium phthalocyanines having a-phase and β-phase were investigated with the differences of crystal phase using X-ray powder diffraction, spectroscopic, nuclear magnetic and photoelectroscopic methods. The TiOPc was quite different from bivalent metal phthalocyanines. The TiOPc have characteristic X-ray powder diffraction patterns, i. e., the orientation of the (010) face with a-phase and the (001) face with β-phase, respectively, were very high compared with other faces. Because of the larger intermolecular force, the visible absorption peak of a-phase shifted toward longer wavelength. The infrared spectra in 700~800 nm region showed the vibrational energy in IR region of β-phase was larger than that of a-phase. Solid-state 18C-NMR spectra suggested β-phase has high regularity on its nuclear magnetic resonances. The XPS spectra of TiOPc gave the proportion of carbon at benzene ring and bonded to nitrogen in TiOPc molecule. The β-phase has much adsorped oxygen than a-phase, because of its longer distances of each molecules. For the TiOPc, the transformation of crystal phases from thermally metastable a-phase to stable β-phase were suggested by the analysis of the heated samples at various temperatures. © 1990, The Chemical Society of Japan. All rights reserved.