Non-adiabatic transitions from the I2(E) induced by the transition dipole moment of I2(E–D) and the electric dipole moment of collision partners

Optical–optical double resonance spectroscopy is used to obtain total rate constants, electronic branching ratios, and vibrational product state distributions for non-adiabatic transitions among the first-tier ion-pair states of the I2 molecule excited to the E 0 g + , v E = 8 , 13 , 19 ;JE ≈ 55 rovibronic levels in collisions with M = CD3I and CH3COCH3. It is shown that I 2 ( E → M D ) near-resonant transitions are caused by the interaction between the transition dipole moment of I2(E–D) and the permanent electric dipole moment of M. The I2(D) state vibrational levels populated due to polarization interaction accompanied by quasi-resonance excitation of the collision partner are also observed.