ELECTRONIC QUENCHING RATES FOR NO(A2-SIGMA+) MEASURED IN A SHOCK-TUBE

We report rate coefficients for electronic quenching of NO (A 2-SIGMA+) by NO(X 2-PI), CO2, Ar and He measured at high temperature behind reproducible shock waves. NO and CO2 are efficient quenchers at temperatures between 300 and 2100 K while the rare gases quench much less efficiently. We develop a model to predict the temperature dependence of NO(A 2-SIGMA+) quenching by collision partners that have a large electron affinity and thereby enable a charge-transfer complex (NO+X-) to mediate the transition between the A 2-SIGMA+ nu' = 0 and X 2-PI states of NO.