EXCITED SINGLET STATE STRUCTURE AND DYNAMICS OF ISOLATED DIPHENYLPOLYENES
Loading...
Date
1984
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
One photon fluorescence excitation spectra, fluorescence spectra, and single vibrational level decay kinetics have been measured for $diphenylbutadiene^{1}$ (DPB) and $diphenylhexatriene^{2}$ (DPH) seeded in supersonic helium expansions. In each case a long lived (52.8 nsec for DPB and 90.7 nsec for DPH) doubly excited $^{1}A^{\ast}_{g}$ state is located well below the lowest singly excited state $(1 ^{1}B^{\ast}_{u})$. The $^{1}A^{\ast}_{g}$ to $1 ^{1}B^{\ast}_{u}$ energy gap is $1150 cm^{-1}$ for DPB and $3400 cm^{-1}$ for DPH. All of the observed vibrational states have odd inversion symmetry and are coupled to the $1 ^{1}B^{\ast}_{u}$ state. Emission produced by excitation of this $1 ^{1}B^{\ast}_{u}$ state emanates not from this state but from vibrationally excited levels of the $^{1}A_{g}$ state which are isoenergetic with the initially prepared state. Comparisons of the gas phase data obtained here with that obtained in low temperature matrices provides a clearer picture of the photodynamics and electronic structure of diphenylpolyenes than was previously available.
Description
$^{1}$ Lou Ann Heimbrook, Bryan E. Kohler, and Thomas A. Spiglanin, Proc. Natl. Acad. Sci. USA 80, 4580 (1983) $^{2}$ Bryan E. Kohler and Thomas A. Spiglanin, accepted, J. Chem. Phys. (1984).
Author Institution: Department of Chemistry, Wesleyan University
Author Institution: Department of Chemistry, Wesleyan University