Optical absorption and emission spectra at liquid helium temperatures of solutions of α,ω-diphenyloctatetraene (DPO) in single crystal bibenzyl and polycrystalline n-paraffins have been measured. These measurements show that (1) there is an excited singlet state at lower energy than the 1B1u state responsible for the strong absorption at 4100 Å: (2) the presence of this state rationalizes a number of distinctive characteristics of polyene spectra which had previously been explained on the basis of "Franck-Condon forbiddeness". Evidence that these results describe a general property of polyene electronic structure which is not specific to DPO is presented.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Condensed Matter Physics
- Atomic and Molecular Physics, and Optics
- Surfaces and Interfaces