Unlocking Singlet Oxygen: Fluorinated Phthalocyanines in Homogeneous and Heterogeneous Photocatalysis

The adsorption and photocatalytic properties of fluorinated phthalocyanines (F64PcZn and F16PcZn [1,2]) on galuminum oxide solid support were investigated. The phthalocyanines along with their metal oxide complexes were characterized by diffuse reflectance, infra red and fluorescence spectroscopies along with thermogravimetric analysis. Phthalocyanines act as photosensitizers using visible light to generate singlet oxygen (1O2) which can react to form other reactive oxygen species (ROS).[3] The degradation of organic sulfides of interest was investigated under several conditions: homogenous photocatalysis using F16PcZn and F64PcZn; heterogeneous photocatalysis using F16PcZn and F64PcZn respectively adsorbed on g- alumina. Supported catalyst kinetics were analyzed using UV-Vis. Degradation products were confirmed using GC-MS and reaction kinetics were analyzed using GC-FID. Complexes in solvent-rich systems followed first order kinetics. In a separate study perfluorinated phthalocyanine F16PcZn was used as a core for hyperbranched polyphenylene sulfide polymers. Several polyhalogenated thiophenols were used as the monomers, with polymerization typically in N-methylpyrrolidone (NMP). Both organic (DBU) and inorganic (K2CO3) bases were used to initiate polymerization. The resulting materials were characterized by a number of techniques, including IR, NMR, UV-Vis-NIR, along with thermal methods like differential scanning calorimetry. The ability of the materials to catalyze photo-oxidation reactions was evaluated.