Effect of Solvent Perturbation on theS3thinsp;rarr;thinsp;S1Internal Conversion Efficiency of Benzene, Toluene, andphyphen;Xylene

摘要

TheS3thinsp;rarr;thinsp;S1internal conversion efficiency of benzene is found to depend critically on the effectiveness of environmental perturbation in mixing theS3andS1states. Evidence for this derives from the experimental correlation of the conversion efficiency with the intensities of the 0ndash;0 absorptive and emissive transitions in solutions with the solvents benzene, methanol, isopropyl alcohol, tetrahydrofuran, ethyl ether, acetonitrile, hexane, cyclohexane, methylcyclohexane, decalin, isooctane, and perfluorinated hexane. Additionally, the importance ofS3thinsp;minus;thinsp;S1mixing is shown to explain the marked increase in the efficiency of internal conversion observed upon methyl substitution of benzene.