Theoretical determination of the spectral and luminescence properties of complex molecules to assess their lasing capacity

A method of determining the lasing capacity of complex molecules is proposed. This is based on general theory of intramolecular excitation energy redistribution processes and quantum-chemical calculations of the electronic structure, oscillator strengths, and loss spectra in systems of triplet and singlet excited states. The nature of the forbidden and allowed excited states is determined and laws governing changes in the spectral and luminescence characteristics, essential for laser action are determined for a large class of benzoxazoles as a function of the molecular structure. Lasing compounds are identified and laser action is reported for new compounds in the ultraviolet.