LOW-TEMPERATURE SPECTROSCOPY AND PHOTOCHEMISTRY OF DIANTHRACENE

The centrosymmetric molecule, dianthracene, has four low-lying excited singlet states arising due to interactions between the four equivalent benzene chromophores in the molecule. An empirical model identifies the lowest excited state as 1B3g with the other three states at increasingly higher energies being 1B1u, 1B2u, and 1Ag. The energy gap between the low temperature emission and fluorescence excitation spectra of crystalline dianthracene as well as the shape of the origin absorption spectrum and the lack of site-selected spectra in this region for dianthracene in a low temperature polymer host provide strong support for this predicted state ordering. The temperature dependence of the quantum yield for photodissociation of the dianthracene molecule and the emission spectrum of the anthracene pairs formed by this reaction are also presented. © 1992, Taylor & Francis Group, LLC. All rights reserved.