TY - JOUR
T1 - Photochemistry of doubly N-confused porphyrin bonded to non-conventional high oxidation state Ag(III) and Cu(III) ions
AU - Engelmann, Fábio M.
AU - Mayer, Ildemar
AU - Araki, Koiti
AU - Toma, Henrique E.
AU - Baptista, Maurício S.
AU - Maeda, Hiromitsu
AU - Osuka, Atsuhiro
AU - Furuta, Hiroyuki
N1 - Funding Information:
The authors thank Fundação de Amparo à Pesquisa do Estado de São Paulo, Conselho Nacional de Desenvolvimento Cientı́fico e Tecnológico and RENAMI, for the financial support.
PY - 2004/5/21
Y1 - 2004/5/21
N2 - The photophysical properties of the free base, silver(III) and copper(III) doubly N-confused porphyrin complexes were examined. The free base species exhibits a low fluorescence quantum yield of 9.1×10-3, which is completely suppressed in the M(III) complexes. However, high singlet oxygen quantum yields were found for the Ag(III) (φΔ=0.92) and Cu(III) (φΔ=0.66) complexes. These results were ascribed to the enhanced intersystem crossing rates, induced by heavy atom effect, rather than to a redox quenching involving the metal ions in unusually high oxidation state. The confused porphyrins are photochemically stable in oxygen-free solution but are bleached more or less rapidly by the photogenerated singlet oxygen, in the absence of other quenchers.
AB - The photophysical properties of the free base, silver(III) and copper(III) doubly N-confused porphyrin complexes were examined. The free base species exhibits a low fluorescence quantum yield of 9.1×10-3, which is completely suppressed in the M(III) complexes. However, high singlet oxygen quantum yields were found for the Ag(III) (φΔ=0.92) and Cu(III) (φΔ=0.66) complexes. These results were ascribed to the enhanced intersystem crossing rates, induced by heavy atom effect, rather than to a redox quenching involving the metal ions in unusually high oxidation state. The confused porphyrins are photochemically stable in oxygen-free solution but are bleached more or less rapidly by the photogenerated singlet oxygen, in the absence of other quenchers.
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U2 - 10.1016/j.jphotochem.2004.01.010
DO - 10.1016/j.jphotochem.2004.01.010
M3 - Article
AN - SCOPUS:2342652221
SN - 1010-6030
VL - 163
SP - 403
EP - 411
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
IS - 3
ER -