title: Electron Transfer Catalyzed [2 + 2] Cycloreversion of Benzene Dimers.
abstract: The catalysis of the [2 + 2] cycloreversion of the anti-o,o'-benzene dimer 1 and the syn-o,o'-naphthalene-benzene dimer 2 through thermal and photoinduced electron transfer is studied using experimental and computational methods. The reaction of the radical cations formed by electron transfer is at least 10(5) times faster than the thermal background reaction. It is demonstrated that the photoinduced electron transfer catalyzed reaction proceeds via an electron transfer sensitized pathway and that the observed inverse secondary deuterium isotope effect of 0.91 +/- 0.02 on the reaction is due to the equilibrium isotope effect on the electron transfer step. The relevance of these findings on the mechanism of the electron transfer catalyzed [2 + 2] cycloreversion of the biologically important cis,syn-cyclobutane-thymine dimer is also discussed.
authors.affiliation: Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200.
authors.forename: G. Devi
authors.initials: GD
authors.lastname: Reddy
authors.forename: Olaf
authors.initials: O
authors.lastname: Wiest
authors.forename: Tomas
authors.initials: T
authors.lastname: Hudlicky
authors.forename: Valeria
authors.initials: V
authors.lastname: Schapiro
authors.forename: David
authors.initials: D
authors.lastname: Gonzalez