Chlorosubstituted Copper Phthalocyanines: Spectral Study and Structure of Thin Films

Abstract

In this work, the tetra-, octa- and hexadecachloro-substituted copper phthalocyanines CuPcClx (where x can equal 4, 8 or 16) were investigated by the methods of vibrational (IR and Raman) spectroscopy and X-ray diffraction. The assignment of the most intense bands, both in IR and Raman spectra, was carried out on the basis of DFT calculations. The structure of a CuPcCl4 single crystal grown by sublimation in vacuum was refined for the first time. The effect of chloro-substitution on the structure of CuPcClx thin films deposited in a vacuum onto a glass substrate at 50 and 200 °C was studied. It was shown that CuPcCl4 formed polycrystalline films with the preferential orientation of the (100) crystallographic plane of crystallites parallel to the substrate surface when deposited on a substrate at 50 °C. Introduction of more Cl-substituents into the phthalocyanine macrocycle leads to the formation of amorphous films on the substrates at 50 °C. At the elevated substrate temperature, the growth of polycrystalline disordered films was observed for all three copper phthalocyanines.

Keywords

• phthalocyanines
• single crystal structure
• thin films
• X-ray diffraction
• vibrational spectra
• DFT calculations