Unit Cell Metastable-form Constants of Various Phthalocyanines

Abstract

Thin films of phthalocyanine compounds formed on cleaved surfaces of muscovite by the vacuum-condensation method showed well-defined single-directional orientation when their substrates were preheated at 300°C for one hour and then kept at 150°C. Their electron diffraction patterns were fiber diagrams, the fiber period of which coincided with the unit-cell length of the b-axis of the individual compounds. When the substrates were preheated at 400°C for one hour and then kept at 150°C, the films formed on the muscovite surface were composed of discrete crystals with a different orientation. Electron-diffraction patterns from the films revealed that the b-axis of the crystal was inclined to the substrate surface. The cross-grating patterns of the (h0l) plane were obtained when the inclination of the films was properly adjusted to the incident beam. The unit-cell constants of platinum-phthalocyanine vacuum-condensed on muscovite were revealed to be as follows with the monoclinic space group C2⁄c: a=23.18 Å, b=3.818 Å, c=23.84 Å, and β=91.9 °. Films of Cu-, Co-, Fe-, Ni- and metal-free phthalocyanines exhibited an orientation similar to that of the platinum derivative. High-resolution electron-diffraction patterns revealed that all the compounds assumed a conspicuous isomorphism with one another and occurred in the metastable forms of their dimorphs.