Photophysical and Redox Properties of Water-Soluble Porphyrins in Aqueous Media

Article abstract of DOI:10.1021/j100223a022

Various photophysical (spectra, lifetimes, and quantum yields for fluorescence, phosphorescence, T-T absorption spectra, and quantum yields for triplet formation) and redox (potentials for one-and two-electron oxidation and reduction) properties of several water-soluble porphyrins (H2TPPS, H2TMPyP, ZnTPPS, ZnTMPyP, ZnTPPC, PdTPPS, PdTMPyP, and PdTPPC where TPPS=tetrakis(sulfonatophenyl)porphyrin, TMPyP=tetrakis(N-methylpyridyl)porphyrin, and TPPC=tetrakis(carboxyphenyl)porphyrin in aqueous solution have been studied.The tetrakis(N-methylpyridyl)porphyrins are characterized by reduced fluorescence yields, higher triplet yields, and long lifetimes with intense T-T absorptions extending up to 1200 nm.The redox potentials of these cationic porphyrins are also shifted to more positive potentials by 350-400 mV with respect to those of anionic TPPS systems.