14N/15N kinetic isotope effect in the association reaction O(3P)+NO+Ar→NO2+Ar

The termolecular rate constants for the O(3P)+14NO+Ar→14NO2+Ar and O(3P)+15NO+Ar→15NO2+Ar reactions were determined under room temperature bulk conditions. O(3P) was produced by the pulsed photodissociation of SO2 at 210.4 nm and was monitored by two-photon laser-induced fluorescence at 225.7 nm. The rate constants for 14NO and 15NO were determined to be 5.4±0.2 and 6.1±0.3×10−32 cm6 s−1, respectively. The error limits are twice the standard errors (S.E.). This isotope effect is opposite to that expected from a statistical model but is similar to that observed in the O3 formation reactions from O(3P) and O2.