1 Introduction Much research work has been done on the mechanism of photo-induced reduction of quinone dyes by electron donors with visible light. Two ways to obtain the net two-electron reduction product QH^- bave be...1 Introduction Much research work has been done on the mechanism of photo-induced reduction of quinone dyes by electron donors with visible light. Two ways to obtain the net two-electron reduction product QH^- bave been proposed. One is the direct two-electron transfer (electron-proton-electron transfer) within the complex and the other is the disproportionatioh of the semiquinone radical QH·formed by one-electron transfer.展开更多
The reduced form of the nicotinamide-adenine dinucleotide coenzyme(NAD(P)H)plays an important role in many bio-reductions by transferring a hydride ion or an electronto the surrounding substrate(see eq.(1),R represent...The reduced form of the nicotinamide-adenine dinucleotide coenzyme(NAD(P)H)plays an important role in many bio-reductions by transferring a hydride ion or an electronto the surrounding substrate(see eq.(1),R represents adenine dinucleotide).展开更多
The reaction between chloranil and N-benzyldihydronicotinamide(BNAH)in borate buffer/DMF was investigated.The reaction mixture gave a strong esr signal,which is consistent with that of chloranil anion radical,and tetr...The reaction between chloranil and N-benzyldihydronicotinamide(BNAH)in borate buffer/DMF was investigated.The reaction mixture gave a strong esr signal,which is consistent with that of chloranil anion radical,and tetrachlorohydrophenol(QH_2)and N-benzylnicotinamide (BNA^+)were obtained as the sole products.When the reaction was run in benzene solution,a green coloured charge-transfer complex between the reactants could be isolated,which decomposed in polar solvents to give BNA-+ and QH_2.Based on kinetic studies by esr spectroscopy by the stopped-flow technique,a two-step electron-transfer mechanism for the reactionis proposed in contrast to the hydride-transfer mechanism reported in the literature.展开更多
基金Project supported by the National Natural Science Foundation of China
文摘1 Introduction Much research work has been done on the mechanism of photo-induced reduction of quinone dyes by electron donors with visible light. Two ways to obtain the net two-electron reduction product QH^- bave been proposed. One is the direct two-electron transfer (electron-proton-electron transfer) within the complex and the other is the disproportionatioh of the semiquinone radical QH·formed by one-electron transfer.
文摘The reduced form of the nicotinamide-adenine dinucleotide coenzyme(NAD(P)H)plays an important role in many bio-reductions by transferring a hydride ion or an electronto the surrounding substrate(see eq.(1),R represents adenine dinucleotide).
文摘The reaction between chloranil and N-benzyldihydronicotinamide(BNAH)in borate buffer/DMF was investigated.The reaction mixture gave a strong esr signal,which is consistent with that of chloranil anion radical,and tetrachlorohydrophenol(QH_2)and N-benzylnicotinamide (BNA^+)were obtained as the sole products.When the reaction was run in benzene solution,a green coloured charge-transfer complex between the reactants could be isolated,which decomposed in polar solvents to give BNA-+ and QH_2.Based on kinetic studies by esr spectroscopy by the stopped-flow technique,a two-step electron-transfer mechanism for the reactionis proposed in contrast to the hydride-transfer mechanism reported in the literature.
