Collision-Induced $$ State-to-State Energy Transfer in I₂

Electronic energy transfer in the $$ system of I₂ is investigated in an experiment, where single rovibrational quantum states are prepared, single collision conditions prevail, and the final states have been determined from dispersed fluorescence. In $$ the collisional decay is found to be governed by minimum energy transfer. With (X=I₂) an anomalous behaviour is found for the initially prepared E, ν = 8, J = 56 level, which is tentatively ascribed to vibrational excitation of the collision partner.