Observation of collision induced state-to-state energy transfer in electronically and highly rotationally excited NH2

State-to-state energy transfer of NH2 in its excited state (A) over tilde ( 2)A(1) is investigated with time-resolved Fourier transform emission spectr oscopy. Originating from collisions with NH3, rovibrational energy transfer in NH2((A) over tilde (2)A(1)) with energy separations \DeltaE\ < 260 cm(- 1) and in multiples of DeltaE approximate to -1050 cm(-1) is observed. Base d on the experimental determination of relative transition probabilities, a bsolute state-to-state rate constants are derived. Collisional changes in t he rotational quantum number range from -3 to +4. The analysis of the time dependence of the levels populated by rovibrational energy transfer shows t hat this variety is not the result of secondary collisions. (C) 2001 Americ an Institute of Physics.