Photochemistry of a butylene linked porphyrin quinone donor-acceptor system studied by time-resolved and steady-state EPR spectroscopy

被引：5

作者：

Kay, CWM

Kurreck, H

Batchelor, SN

Tian, P

Schlupmann, J

Mobius, K

机构：

[1] FREE UNIV BERLIN, INST ORGAN CHEM, D-14195 BERLIN, GERMANY

[2] FREE UNIV BERLIN, INST EXPTL PHYS, D-14195 BERLIN, GERMANY

来源：

APPLIED MAGNETIC RESONANCE | 1995年 / 9卷 / 04期

关键词：

D O I：

10.1007/BF03162355

中图分类号：

O64 [物理化学（理论化学）、化学物理学]; O56 [分子物理学、原子物理学];

学科分类号：

070203 ; 070304 ; 081704 ; 1406 ;

摘要：

Radicals generated photochemically from a covalently linked porphyrin-quinone donor-acceptor system dissolved in reversed micelles and isotropic solution have been studied by steady-state and time-resolved EPR spectroscopy. In these systems photoinduced intramolecular as well as intermolecular electron transfer processes occur which result in the formation of semiquinone radical anions and porphyrin radical cations. Disproportionation of the semiquinone leads to the formation of porphyrin-hydroquinone (and porphyrin-quinone). The porphyrin-hydroquinone is itself photoactive and reacts through the photoexcited triplet state of the porphyrin. Reduction of the porphyrin to the dihydro form - probably via hydrogen abstraction by the photoexcited porphyrin from the hydroquinone - appears to be the dominant reaction. Once formed the dihydroporphyrin undergoes further similar photochemistry. Emissively polarized spectra are observed from these systems in steady-state EPR experiments. Time-resolved EPR indicates that this polarization is essentially due to the radical tripler pair mechanism.

引用

页码：459 / 480

页数：22

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