The bahavior of palladium(II), platinum(II) and rhodium(II) complexes with two cationic water-soluble porphyrins: meso-tetrakis (4-N-methylpyridyl) porphyrin and meso-tetrakis (4-N,N,N trimethylamoniphenyl)porphyrin in Nafion membrane and in Nafion solution have been studied by UV-visible absorption and emission spectroscopy. All metalloporphyrins are localized in the interfacial region of Nafion. The six coordinate Rh(III) complexes are monomeric inside Nafion, but immobilized four-coordinate Pd(II) and Pt(II) complexes form face to face dimers with a characterisitic blue shifted Soret band. All immobilized complexes exhibit a strong red phosphorescence at room temperature in the absence of oxygen. Phosphorescence decays for all metalloporphyrins were found to be a single exponential but phosphorescence lifetimes noticeably increased in the Nafion membrane as compared to lifetimes in aqueous solution.
Spectral properties of cationic water-soluble metalloporphyrins immobilized in a perfluorosulfonated ion-exchange membrane
MALDOTTI, Andrea;MOLINARI, Alessandra
2004
Abstract
The bahavior of palladium(II), platinum(II) and rhodium(II) complexes with two cationic water-soluble porphyrins: meso-tetrakis (4-N-methylpyridyl) porphyrin and meso-tetrakis (4-N,N,N trimethylamoniphenyl)porphyrin in Nafion membrane and in Nafion solution have been studied by UV-visible absorption and emission spectroscopy. All metalloporphyrins are localized in the interfacial region of Nafion. The six coordinate Rh(III) complexes are monomeric inside Nafion, but immobilized four-coordinate Pd(II) and Pt(II) complexes form face to face dimers with a characterisitic blue shifted Soret band. All immobilized complexes exhibit a strong red phosphorescence at room temperature in the absence of oxygen. Phosphorescence decays for all metalloporphyrins were found to be a single exponential but phosphorescence lifetimes noticeably increased in the Nafion membrane as compared to lifetimes in aqueous solution.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
