Generation of Triarylamine Radical Cations through Reaction of Triarylamines with Cu(II) in Acetonitrile. A Kinetic Investigation of the Electron-Transfer Reaction

摘要: Triphenylamine derivatives react with Cu2+ in acetonitrile to give radical cations, which subsequently undergo dimerization provide tetraphenylbenzidine derivatives. Kinetic aspects of cation formation were examined by stopped-flow spectrophotometry. A broad range triphenylamine studied, and the driving force for electron-transfer reaction ranged from +3.67 −8.56 kcal M−1 rate constants varying 1.09 × 102 2.15 105 s−1 these systems. Reorganization energy was estimated using experimentally determined activation parameters. Fitting data Marcus equation different values electronic coupling matrix element Hel provided a good fit = 100 cm−1 suggesting that electron transfer TPA/Cu2+ system conforms Marcus-type transfer. Furthermore, high reorganization obtained studies is consistent significant bond cleavage transition state, ...