Thermal electron attachment to NO. I. The mechanism and the three-body rate constants

Abstract

Mechanism of thermal electron attachment in pure NO and NO–M mixtures (M: He, Ne, Ar, H2 , CO2 , and n-C4H10 ) at room temperature has been studied by using a pulse radiolysis–microwave cavity technique. The pressure dependence of the attachment rates indicates that a collisional electron detachment from NO− competes with electron attachment at relatively low pressures but three-body attachment dominates at higher pressures. The three-body rate constants in pure NO is (6.5±0.2)×10−31 cm6 molecule−2 s−1 and those values for the other gases as third bodies range from 1×10−32 (for He) to 3.6×10−30 cm6 molecule−2 s−1 (for n-C4H10), and no systematic correspondence can be seen between the values obtained here and those estimated previously from the data of reverse (electron detachment) processes.