Photooxidation of zinc tetraphenylporphyrin by benzoquinone: a Fourier transform electron paramagnetic resonance investigation

Photoinduced electron transfer from zinc myoglobin to benzoquinone studied by FT-EPR

“…8(b). Unlike the ZnMb system, the rate is not linear in [BQ], which is similar to the ZnTPPÈ BQÈethanol system and has already been interpreted by van Willigen et al 38 and were ca. 50 ns and 0.7 ls, respec-T 1T T 1R tively, and did not show any clear dependence on [BQ].…”

“…5) in both the ZnMb and ZnTPPS systems is interpreted by an electron exchange between BQ~and BQ. 38 9 The rates obtained in the present work seem to be surprisingly large compared with those of their system, when we taken into account that our system is not an intramolecular one. This strongly suggests that the reaction in the ZnMbÈBQ system should occur at the surface sites near ZnPP.…”

C60 as a Photocatalyst of Electron-Transfer Processes: Reactions of Triplet C60 with Chloranil, Perylene, and Tritolylamine Studied by Flash Photolysis and FT-EPR

“…The time evolution of the CA - signal is described by a model that takes into account rates of radical formation and decay as well as generation and decay of RPM CIDEP. The least-squares fit of the CA - data, shown by the solid line in Figure b, gives a pseudo-first-order rate constant of radical formation of k f = (2.0 ± 0.3) × 10 5 s -1 and a spin−lattice relaxation rate of 0.19 × 10 6 s -1 ( T 1 D = 5.3 μs).…”

Application of Fourier transform electron paramagnetic resonance in the study of photochemical reactions

“…For comparison, the linewidth found for ZnTPP/BQ in ethanol is 0.26 MHz. 68 The large line width in the silica/alcohol environment can be due to a number of factors: there can be a line-width contribution from spin-spin interaction between redox partners, incomplete averaging of hyperfine and g value anisotropies may play a role, and homogeneous electron transfer is expected to affect the line width.…”