The gas phase kinetics of reactions of alkali metal atoms with nitric oxide

Time-resolved atomic resonance absorption spectroscopy was employed, with flash-photolysis generation of atomic potassium and sodium at 734 K, to investigate the kinetics of K + NO + Ar and Na + NO + Ar. The low-pressure limit recombination rate constants are (1.0 {+-} 0.2) x 10{sup {minus}31} and (1.9 and 0.5) x 10{sup {minus}32} cm{sup 6} molecule{sup {minus}2} s{sup {minus}1}, respectively. Mainly ionic, triplet state adducts are predicted. RRKM modeling yielded K-NO and Na-NO bond dissociation enthalpies of 104 and 66 kJ mol{sup {minus}1}, which compare well with UQCISD(T)/6-311+G(2d) ab initio values of 81 and 68 kJ mol{sup {minus}1}, respectively. For Li + NO + Ar, the predicted binding energy is 134 kJ mol{sup {minus}1}, which yields a predicted rate constant of 1.4 x 10{sup {minus}31} cm{sup 6} molecule{sup {minus}2} s{sup {minus}1}.