Chemiluminescence in reactions of N+ ions with hydrogen and hydrocarbons. II. Dependence of total reaction cross sections on the collision energy

Chemiluminescent reactions between N+ ions and H2 as well as some hydrocarbons were studied up to ∼450 eVCM collision energy. Emission from NH(A 3Π) and, with hydrocarbons, from CH(A, B, and C) as well as from C and H atoms was observed. Except in the H2 case, the formation of NH(A) in a bimolecular exchange reaction occurs up to 150 eVCM. Below 20 eVCM this reaction appears to proceed by direct interaction between the N+ projectile and an H atom, while at high energies the primary interaction is between N+ and a C atom. The approximately exponential falloff of the cross section for NH(A) formation above 50 eVCM was explained in the case of CH4 using a soft-sphere collision model. A hard-sphere model was used in an attempt to explain the measured ratio of the N++C2H4 and N++CH4 cross sections. Computer trajectory studies revealed the relative importance of various types of collision and led to semiquantitative agreement with experiment.