Dimerization of aluminum tetrasulfo-phthalocyanine chloride in sol–gel process

Abstract

We report here the study of aluminum tetrasulfo-phthalocyanine chloride (AlTSPcCl)-doped silica xgel obtained by sol–gel technique. Because the issue of dimerization is vital in determining the optical properties of dye doped sol–gel materials and phthalocyanine offers an excellent opportunity to characterize dimers from monomers because of their identified absorption bands, we study the dimerization of different concentrations of AlTSPcCl-doped composites by electronic absorption spectra. Proceeding of the absorption spectra was correlated with various stages of the sol–gel process. The results show the composites AlTSPcCl concurrence in the forms of monomer and dimer. Dimerization behaves differently in the early and latter stage of sol–gel transition. Two reasons are given from the change of the micro-environment in which AlTSPcCl existed during the sol–gel process.