An investigation on the self-aggregation properties of sulfonated copper(II) phthalocyanine (CuTsPc) thin films

A novel approach to fabricate thin films of sulfonated copper(II) phthalocyanine (CuTsPc) is reported. After first forming an adhesive layer on hydrophilic and negatively charged substrates (glass or silicon), layers of CuTsPc were assembled by cycles of dipping in solutions of CuTsPc at acidic and basic pH, respectively. UV-vis spectra evidenced film uniformity, while SEM showed the presence of supramolecular assemblies comprising mainly micron-scale aggregates of different shape. The results herein reported seem to suggest that the mechanism of assembly is driven by pi-pi interactions between CuTsPc molecules. (C) 2008 Elsevier B.V. All rights reserved.