Solvent Shifts, Spectroscopy and Structure in Van Der Waals Complexes of Perylene

Laser induced fluorescence has been observed from weakly bound complexes formed in supersonic free jet expansions of perylene with rare gas atoms and several organic “solvent” molecules using helium as carrier gas. The fluorescence excitation spectra of the perylene-solvent complexes displayed a considerable variety of intermolecular vibrational structures which were strongly sensitive to the nature of the solvent molecule. Model calculations of the potential surfaces for these van der Waals complexes (vdW) expressing the interaction energy as the sum of pair potentials between the atoms in the molecules, have been used to determine equilibrium geometries and binding energies.