Yoshihisa MATSUSHITA (Tokyo Inst. Tech.), Shogo NOGUCHI (Tokyo Inst. Tech.), Naotaka OHIWA (Tokyo Inst. Tech.) and Kinichi OBI (Tokyo Inst. Tech. and IMS)
[J. Photochem. and Photobio. A: Chem. 102, 93 (1996)]
Photochemical reaction in the neutral molecular clusters of benzophenone with hydrogen donors formed in a supersonic free jet expansion has been studied. It has been found that intracluster hydrogen abstraction reaction takes place to form benzophenone ketyl radical in the benzophenone-1,4-cyclohecadiene mixed cluster. On the contrary, no ketyl radical has been detected when ethanol, 2-propanol, or several kinds of amine are used as a hydrogen donor. Excitation and emission spectra of the benzophenone-N,N-dimethylaniline cluster have suggested that benzophenone and N,N-dimethylaniline form a ground state charge transfer complex. The excitation of the benzophenone-tri-n-butylamine cluster promotes the transformation to the van der Waals complex to an exciplex. The reactivity of the clusters on hydrogen abstraction and charge transfer reactions has been discussed on the basis of the nature of hydrogen donors.