title: Intermediates Produced in the Electron-Transfer Processes of Phenothiazine/Semiconductor Systems.
abstract: Phenothiazine radical cation PTH(+*) and phenothiazine dication PTH(2+) produced by photoinduced electron transfer in phenothiazine/semiconductor systems have been studied by using ESR, UV-visible absorption, and fluorescence spectroscopic methods. It is found that the PTH(+*) was generated by electron transfer from (1)PTH* and (3)PTH* to the conduction band of the semiconductors besides PTH(+*) resulted in the photoionization of PTH as well as PTH(2+) produced by electron transfer from PTH(+*) to the conduction band of the semiconductors successively. Very significant supplementary information provided by UV-visible absorption, ESR, and resonance Raman spectra of PTH(+*) and PTH(2+), which were obtained by oxidation of PTH with lead tetraacetate, not only confirmed the two-step mono-electron-transfer mechanism proposed for interpretation of electron-transfer processes in PTH/semiconductor systems but also demonstrated that the two successive electron-transfer steps were corresponding to the removal of a p-electron at the nitrogen atom and a p-electron at the sulfur atom in the PTH molecule, respectively. Consequently, the nonplanar configuration of the PTH molecule changed into a planar configuration of the PTH(2+). Copyright 2000 Academic Press.
authors.affiliation: Institute of Chemistry, Academia Sinica, Beijing, 100080, People's Republic of China
authors.initials: H
authors.lastname: Jian
authors.initials: J
authors.lastname: Xiang
authors.initials: K
authors.lastname: Sun
authors.initials: J
authors.lastname: Sun
authors.initials: C
authors.lastname: Chen
authors.initials: B
authors.lastname: Zhou
authors.initials: Y
authors.lastname: Liu
authors.initials: G
authors.lastname: Xu