CHARACTERIZATION OF PHOTOINDUCED ELECTRON-TRANSFER IN JET-FORMED ACCEPTOR-DONOR COMPLEXES - 1 - ISOMERIC FORMS OF COMPLEXES OF ANTHRACENE WITH ANILINE DERIVATIVES

The existence of isomeric forms of donor-acceptor complexes formed in the supersonic expansion was evidenced by their fluorescence, fluoresc ence excitation, and hole-burning spectra. For each complex, we observ ed two types of isomers: one E-isomer with broad structureless excitat ion spectra yielding diffuse, strongly red-shifted exciplex emission a nd a number of (one to five) R-isomers with narrow band excitation spe ctra yielding a resonant emission upon the excitation of the lowest vi brational levels of the excited electronic state and exciplex emission from higher levels. A detailed analysis of their excitation spectra ( spectral shifts, vibrational structures, bandwidths) is given. The sha pe of the ground-state potential energy surface (depths and positions of the energy minima, heights of energy barriers, etc.) was determined by calculations involving the ''exchange perturbation'' treatment and simulated annealing method. The relation between the properties of ob served species and calculated configurations is discussed.