Studies on State‐to‐State Energy Transfer of Electronically Excited Atoms and Molecules

Rotationally inelastic collisions of NH 2 ( Ã 2 A 1 ), ∑(0,9,0), 3 03 , 1 01 have been studied by measuring the dispersed fluorescence spectra at molecular beam conditions. The results show that the angular momentum transfer rule is much more successful than is that predicted by energy gap law for fitting the rotational energy transfer rate. For ΔN < 2 the transfer rates are getting slow down. Downward transfer rates are faster than those of upward transfer. With same angular momentum transferred, the transfer rates for Δk a = 0 process are larger than those for Δk a ≠0. It is also found that rotation transfer process is a very efficient way for decaying of the initially pumped levels. About 60% of the initially pumped 3 03 is colliding into other rotational levels. Energy transfer reactions of metastable rare gas atoms (R g *) with N 2 , NH 3 , CS 2 were investigated by measuring the emission spectra. The preferential population of n(A″) of NH(c 1 II) was found in He(2 3 S) + NH 3 reaction, the experimental data shows II(A″)/II(A′) = 1.2 at J′ < 13. A high vibrational excitation and low rotational excitation of N 2 (C 3 n) were observed in Ne( 3 P 02 ) + N 2 reaction comparing with Ar( 3 P 0.2 ) + N 2 reaction. The detailed vibrational populations of CS 2 + (Ã, B̃) achieved by He(2 3 S)/Ne( 3 P 0.2 ) + CS 2 reaction are different from those obtained by PES. The vibrational distributions of CH(A 2 Δ) obtained by He(2 3 S) + CHC1 3 (CH 3 NO 2 ) reactions were discussed based on statistical theory, special attention was paid to reveal the role played by tie angular momentum restriction in this process. The result on energy transfer between N 2 (a 1 Π) and CO(X 1 ∑) was firstly presented by VUV emission spectra at single collision condition. The mechanisms of energy transfer related to some of the reactions mentioned above were also discussed in the text.