COMPARATIVE RAMAN, INFRARED AND OPTICAL SPECTROSCOPIC STUDIES OF THIN-FILMS OF AN AXIALLY SUBSTITUTED PHTHALOCYANINE COMPOUND

A series of thin films of an axially substituted silicon phthalocyanin e, PcSi(OSiCH3C6H5OH)(2), were made by spin coating and vacuum evapora tion techniques. Electronics spectra of these films exhibit a bathochr omic shift of the Q band compared with that of a chloroform solution. This bathochromic shift is ascribed to the formation of aggregates in films as seen by the scanning electron micrographs of them. Neither el ectronic nor vibrational spectra provide evidence for the formation of cofacial dimers which are usually found in evaporated films of axiall y substituted silicon phthalocyanines. The evaporated films that are r edissolved in chloroform exhibit the same electronic and proton NMR sp ectra as the fresh solutions. The Raman and infrared spectra suggest t hat both evaporated and spin-coated films possess similar molecular st ructures.