Electronic Spectra and Electronic Structures of a Series of Bisdehydroannulenes

Abstract
Electronic absorption spectra of tetra-t-butylbisdehydro[14], [18], [22], [26], and [30]annulenes were investigated experimentally and theoretically. SCF MO calculations were carried out by the P-P-P method and random phase approximation (RPA). An assignment of spectra is presented. Fluorescence excitation polarization spectra of tetra-t-butylbisdehydro[14]annulene and the crystalline reflection spectra of tetra-t-butylbisdehydro[18]annulene were studied in order to determine the polarization of the spectra. The assignment was confirmed by these methods.