Organoplatinum(II) Complexes with Chromophore-Acceptor Dyad Studied by Ultrafast Time-Resolved Absorption Spectroscopy

The photoinduced ET reaction from PtIIchromophore to viologen acceptor in a new ultrafast time-resolved absorption spectroscopy has been reported. Photoinduced electron-transfer (ET) reactions are fundamental steps in photosynthesis, and which have led to extensive investigations into charge-separated species in artificial mimics. The development of the absorption maxima at 395 and 605 nm could be attributed to the formation of methyl viologen radical cation as a result of oxidative decomposition of TEOA. The back ET reaction rate constants of the two platinum (II) systems are slower than the forward electron-transfer reactions, despite the large driving force. Efforts to harness the slow back ET reactions of PtII chromophore acceptor systems for light-induced multi-electron-transfer catalysis are in progress.