EXPERIMENTAL STUDY OF THE DYNAMICS OF THE Sn/N2O(O-2) REACTION IN A SUPERSONIC FREE JET

An experimental study of the chemiluminescent reaction of Sn with N2O and O-2 is first performed in a supersonic flow apparatus by using the electric-arc plasma technique to generate atomic Sn vapor. The temperature and pressure in the reaction zone are 900K and 1-10 torr, respectively. The emission spectra of SnO(a(3)Sigma(+) - X-1 Sigma(+)) are recorded using an optical multichannel analyzer (OMA) at different reaction pressures and the dependence of the relative vibrational population of the product SnO(a(3)Sigma(+)), on the pressure has been presented. The vibrational relaxation rates of the SnO(a(3)Sigma(+)) by Ar and Ar + N-2 had been calculated as -10(4) torr(-1) s(-1) by the least square fit of the experimental data. The emissions from the electronically excited state, b(3)Pi and a(3)Sigma(+), in the reaction of Sn + O-2 can be explained in terms of the reactions of Sn-2 + O-2 and Sn2 + O. An unusually high population of a(3)Sigma V+' = 1 in the reaction of Sn + O-2 is also found. The results are compared with those obtained in high-temperature-fast-flow reactor (HTFFR) and the reaction mechanism is discussed.