Picosecond Laser Photolysis Studies of Hydrogen Atom Transfer Reaction via Heteroexcimer State in Pyrene-Primary and Pirene-Secondary Aromatic Amine Systems: Role of "Hydrogen-Bonding" Interaction between Amino Group of Donor and ? Electron Acceptor in the Heteroexcimer

Article abstract of DOI:10.1021/ja00389a049

The mechanism of charge transfer followed by proton transfer in the hydrogen atom transfer reaction of excited pyrene-primary and -secondary amine systems has been directly demonstrated by means of a picosecond laser photolysis method.In the case of pyrene-N-ethylamine heteroexcimer system in hexane, for example, it has been observed that the 1-hydro-1-pyrenyl radical and the pyrene triplet state are produced simultaneously in the time region of subnanosecond to nanosecond.The deuteration of the NH group of the amine affects considerably the rate of formation of the 1-hydro-1-pyrenyl radical but not the rate of intersystem crossing from the heteroexcimer.On the basis of the results obtained for various pyrene-primary and -secondary aromatic amine heteroexcimer systems, the nature of the interaction between donor and acceptor in these heteroexcimers and their conformation in relation to the mechanism of the hydrogen atom transfer reaction via heteroexcimer have been elucidated.