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ENERGY RELAXATION MECHANISM IN Ni(II), Pd(II), Pt(II) and Zn(II) PORPHYRINS
Author(s) -
Kobayashi T.,
Straub K. D.,
Rentzepis P. M.
Publication year - 1979
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1979.tb07793.x
Subject(s) - porphyrin , chemistry , phosphorescence , photochemistry , picosecond , intramolecular force , singlet state , ultrafast laser spectroscopy , excited state , relaxation (psychology) , absorption spectroscopy , kinetics , spectroscopy , fluorescence , stereochemistry , atomic physics , laser , psychology , social psychology , physics , quantum mechanics , optics
—Picosecond absorption spectroscopy was used to determine the intramolecular energy relaxation processes occurring in Ni(II). Pd(II), Pt(II), and Zn(II) protoporphyrin IX dimethyl ester. Picosecond data on the rate of ground state repopulation and the kinetics of a transient intermediate made it possible to determine the lifetimes of the excited singlet state of Ni, Pd, and Zn porphyrins as 10±2ps, 19±3ps, and 2.6±0.5 ps, respectively, and<8 ps for Pt porphyrin. On the basis of these data. the nonfluorescent and nonphosphorescent property of Ni porphyrin can be interpreted in terms of internal conversion to a lower lying singlet d‐d level which is not the case for the strongly phosphorescent Pd and Pt porphyrins.