Solvent and temperature effects on the excited singlet state absorption of diphenylbutadiene.

Nanosecond excited state absorption spectra of all-trans-1,4-diphenyl-1,3-butadiene (DPB) and a rigid s-cis DPB analog, 1,4-diphenyl-1,3-cyclopentadiene, were obtained in several hydrocarbon solvents at room temperature and low temperatures. Analysis of the excited state absorption spectra of these two molecules suggests the presence of excited state s-cis rotamers in DPB at room temperature.