Theoretical studies on the spectroscopy of the 7-azaindole monomer and dimer

The absorption and the emission spectra, both fluorescence and phosphoresce nce, of the 7-azaindole molecule have been studied by means of the complete active space (CAS) SCF method and multiconfigurational second-order pertur bation theory (CASPT2). Excitation energies, oscillator strengths, dipole m oments, transition dipole moments, and their directions have been computed and the results compared to those of analogous molecules such as indene, in dole, and benzimidazole, to get a homogeneous picture of the photophysics o f the systems. The absorption and emission of the 7-azaindole dimer and its related tautomer have also been computed in order to get further insight i nto the double fluorescence phenomenon, which was first observed in highly concentrated media. (C) 2001 John Wiley & Sons, Inc.