Functionalized copper-phthalocyanine in solution and as thin film: photochemical and morphological characterization towards applications

This article reports on an extensive investigation on a functionalized phthalocyanine, namely, copper(II) tetrakis- (isopropoxy-carbonyl)-phthalocyanine (TIPCuPc). The self-association of the molecules is extensively described in solution in different solvents (DMSO, DMF, CHCl3, pyridine) by means ofUV-vis steady state spectroscopy at the air/ water interface by Brewster angle microscopy (BAM) and in thin films by using atomic force microscopy (AFM). We investigated the morphology of TIPCuPc as thin film by evaluating different factors: temperature, solvent, concentration, transferring procedure (spin-coating and Langmuir-Scha¨ fer technique), and nature of the substrate (mica and quartz). The behavior of the molecules underUVlight irradiation and their thermal stability were studied as well. Such a detailed study can allow a suitable processing of this phthalocyanine derivative for future applications. Here the photoelectrochemical activity of the phthalocyanine was investigated when suitably combined as sensitizer with rodlike TiO2 nanocrystals (NCs) in hybrid junctions integrated in a photoelectrochemical cell.