High resolution spectroscopy of diphenyldecapentaene and diphenyldodecahexaene

Abstract

Fluorescence and fluorescence excitation spectra of single crystal and polycrystalline solutions of diphenyldecapentaene in n-decane and diphenyldodecahexaene in n-dodecane have been measured at 77 and 4.2 K. At 4.2 K the spectra are well resolved (FWHM bandwidths ≂10 cm−1) and, for the principal site, the energy for the 2 1Ag(S1) to 1 1Ag(S0) origin band of diphenyldecapentaene in n-decane is 20 133.3 cm−1 and that of diphenyldodecahexaene in n-dodecane is 18 261.4 cm−1. Analysis of these data includes the determination of fluorescence decay rates and C–C and C=C vibrational frequencies in the ground and excited states.