Electronic spectra of matrix-isolated tolan: site selective one- and two-photon spectra

Abstract

Site-selective fluorescence and one- and two-photon fluorescence excitation spectra of low-lying electronic singlet states of tolan (diphenylacetylene) embedded in different matrices (N 2 , Ar, Kr) are presented and discussed. The results are compared to spectra obtained from a Shpolskii matrix and from supersonic jet investigations. Only the fluorescence spectra agree with the results from the jet study. The one- and especially the two-photon excitation spectra exhibit major differency compared to the jet results. CNDO/S-SDCI calculations suggest that the first three excited singlet states are very close together in tolan