Abstract: The study of quenching and rotational statetostate energy transfer of NH2(A1,090,423) with Ar,N2,O2, and NH3 was performed at single collisional conditions. The total quenching cross sections σQ for the four partners have been measured to be ≤0.17 nm2， 0.26 nm2，0.30 nm2 and 0.48 nm2, respectively. The relative cross sections of rotational statetostate energy transfer were obtained by measuring the dispersed fluorescent spectra. A collisioncomplex model was used to calculate the quenching cross sections and the theoretical and experimental values show the same trend. This indicates that long range attractive interactions play an important role in the quenching process. It was also found that the relative cross sections of rotational energy transfer decrease approximately with decreasing the reduced mass of the collisionpair. NH3 and O2 present the larger quenching cross sections and smaller cross sections of rotational energy transfer due to the larger dipole momentum and the electronic structure of openshell, respectively.

Key words: Energy transfer of electronically excited state, Single collision, 　Collision-complex model, NH₂ free radical