Influence of rotational dynamics on collisional depolarization and quenching of molecular luminescence in the gas phase

Theoretical expressions describing the collisional depolarization of the luminescence of polyatomic molecules in the gas phase are obtained taking into account donor molecule rotation in a dynamic excitation-quenching regime. Effects of the quenching cross-section dependence on the rotation rate are examined by numerical calculations for several models. It is shown that the decay of luminescence anisotropy intensifies substantially with the degree of rotational modulation of the energy transfer.