Absorption and Fluorescence Spectra of Anthracene-s-Trinitrobenzene Complex Crystal

The electronic absorption and fluorescence spectra of the single crystal of the anthracene-s-trinitrobenzene complex have been measured, and the polarization property of electronic transitions has been discussed in terms of interaction between the no-bond structure, the charge transfer and the locally-excited state of anthracene. It has been shown that molecules in a pair are displaced to a closer position after the excitation, whereby the mixing of the donor-excited level occurs more than in the ground state (Frank-Condon state), and the fluorescence involves a larger contribution from the in-plane transition of anthracene.