ENERGY TRANSFER IN MOLECULAR COMPLEXES OF SYM TRINITROBENZENE WITH POLYACENES

Author Institution: Coates Chemical Laboratories, Louisiana State University; Department of Chemistry, The Florida State University“The emission spectra of r-complexes of aromatics with sym-trinitrobenzene have been studied. It is shown that after irradiation in the charge-transfer band, two emissions occur: one the reverse of the charge-transfer absorption, the other from a triplet level of the uncomplexed aromatic. Absorption spectra of complexes, their total emission spectra and delayed emissions are described. Theoretical considerations of the processes involved lead us to presume that after excitation in the charge-transfer band, some inter-system crossing occurs to a dissociative triplet level of the complex. The resultant production of uncomplexed aromatic in its lowest triplet state then gives rise to the observed phosphorescence. State correlation diagrams and plots of ionisation potential of aromatic versus the energy of the charge-transfer absorption are described.