Chemical behaviour of oxotitanium(IV) phthalocyanine (OTiPc) solutions associated with the preparation of OTiPC monolayers and multilayers

Abstract

The chemical behaviour of oxotitanium(IV) phthalocyanine (OTiPc) in mixtures of dichloromethane and trihalogenoacetic acids was studied by means of spectroscopic measurements. In dichloromethane–trifluoroacetic acid mixtures, OTiPc was relatively unstable, undergoing gradual decomposition via the radical cation of OTiPc; phtalimide and 3-iminoisoindolin-1-one were isolated. In dichloromethane–trichloroacetic acid mixed solvent, on the other hand, a stable solution of OTiPc was obtained with no formation of the radical cation. A monolayer of OTiPc was formed upon spreading this solution onto the water surface and was deposited on substrates with a horizontal lifting method to form a multilayer film. Polarized visible and near-IR absorption spectra and X-ray diffraction of the film indicated a specific order of molecular orientation.