Abstract: The chemiluminescence reaction of tin with N_2O and O_2 have been investigated in a beam-gas apparatus under the pressure range of 10~(-4)—10~(-2) torr. The chemiluminescent spectra recorded for both reactions under single-collision conditions have been recognized as the emission of b~3Π(0) and b'3Π(1) state to the ground state of SnO produced in the reaction. For the reaction of Sn with N_2O, the emission from a~3∑-X~1∑ transition obviously becomes enhanced with in creasing of background gas pressure. The relative population of a~3∑ state on v=0 and v=1 as well as the emission intensity of a~3∑ and b~1Π(1) states to X~1∑ state of SnO have been measured also. The total cross section of collision is about 0.32 nm. In analyzing the experimental results, it is found that the production of electronically excited SnO molecule from the reaction of Sn with N_2O may proceed with the following mechanism:
Sn(~3P_2)+N_2O(X~1∑)→SnO[b~3Π(0), b′~3Π(1)]+N_2(X~1∑~+_g)
and
Sn+N_2O(X~1∑~+)→SnO(i)+N_2O(X~1∑~+_g)
in which i is a long-lived electronic state.