Reaction Control of Photoinduced Electron Transfer in Porphyrin–Viologen Linked System by the Use of External Magnetic Fields

Abstract

Effects of external magnetic fields on electron transfer reactions in porphyrin–viologen linked systems (ZnPCnV) were investigated by laser photolysis. Rates of reverse electron transfer in the photogenerated intramolecular ion radical pair, as originated from quenching of porphyrin triplet by viologen, were remarkably suppressed (by a factor of ten for n=8) at above 0.1 T. The lifetime of the charge separated state could be correspondingly extended by the use of external magnetic fields, which perturb electron spin relaxation process.

Photoinduced electron-transfer and magnetic-field effects on the decay rates of photogenerated biradicals in a phenothiazine-C60 linked compound with six methylene groups: temperature dependence

“…The effect of spacer chain length on the k dvalues is very interesting and is probably caused by the variation of triplet-singlet energy separation. This is related to the exchange interaction in the biradical, with the interradical distance as pointed out in the case of donor (Ph or ZnP)-viologen compounds [8,24,25].…”

Photocurrent enhancements in a porphyrin-viologen linked compound under plasmonic and magnetic fields

“…The amphiphilic ZnP-V 2+ -linked compound containing six methylene groups [ZnP(6)V] ( Fig. 1) was synthesized as reported previously [39][40][41][42]. The amphiphilic ZnP compound without a V 2+ moiety [ZnP(6)AB] (Fig.…”

“…The amphiphilic ZnP compound without a V 2+ moiety [ZnP(6)AB] (Fig. 1), as a reference, was also synthesized in our laboratory [39][40][41][42]. The purity of ZnP(6)V and ZnP(6)AB was confirmed by 1 H NMR spectra and elemental analysis.…”

Magnetic field effects on photoelectrochemical reactions of modified electrodes with C60-phenothiazine nanoclusters

“…For example, the magnitude of the MFEs in ZnP(n)V-modified electrodes is larger than that in the case of the nanoclusters of the mixture of C 60 N + and MePH. In the transient absorption spectra of ZnP(n)V, the decay rate constants of the photogenerated radical pairs decreased steeply (p0.2 T) and became constant (40.2 T) with increasing magnetic field [31]. In the transient absorption spectra of C 60 N + -MePH-nanocluster, the yield of the escaped radical of MePH increased with increasing magnetic field [25].…”