摘要
本文研究了竹红菌素ＨＡ，ＨＢ以及１３－ＳＯ_３Ｎａ－ＤＤＨＡ在ＤＭＦ－Ｈ_２Ｏ（体积分数＝１）混合体系中的电化学氧化还原性质。结果表明，它们都为两步单电子还原过程，反应机理为：油溶性．水溶性１３－ＳＯ３Ｎａ－ＤＤＨＡ：（第一步）（质子化）；（第二步）．并且，ＨＡ，ＨＢ的单电子还原半醒自由基非常稳定，而１３－ＳＯ_３Ｎａ－ＤＤＨＡ单电子还原半醌自由基存在歧化反应，其速率常数ｋ_ｆ＝０．４０８。
The dectrochemical redox characteristics of hypocrellin A,Band13-5O3Na-DDHA in DMF-H20 mixed system were investigated.The results show/that that all correspond to two step one-electron reduction processes.For oil-soluble system HA and HB,the reactions areHA(HB)+e+H=HAH(HBH)+e=HAH(HBH);for water-soluble system 13-SO3Na-DDHA,the reactions are(the first step)13-SO3NA-DDHA+e=13-SO3Na-DDHA,(protonatbn)13-SO3Na-DDHA-+H+=13-SO3Na-DDHAH,(the second step)13-SO3Na-DDHA+e=13-SO3Na-DDHA,respectively.And it was found that hypocrellin A,B semiquinone radical is very stable,while hypocrellin A sulfonate semiquinone radical is not very stable with a rate constant of disproportionation kf=0.408.
出处
《感光科学与光化学》
CSCD
1996年第1期27-31,共5页
Photographic Science and Photochemistry
