Crossed-beam study of the reaction of van der Waals molecule H+(NO)2

Abstract

Chemiluminescent reaction H+(NO)2 →HNO*+NO was studied under single collision condition. The built-in third body much enhanced the formation of HNO*(A 1A″) in bimolecular relatively large population in bending vibration (ν3 ) as compared with the HNO* produced from the termolecular recombination, H+NO+M. This apparent excitation in bending mode can be attributed to the smaller internal energy of HNO* produced in H+(NO)2 reaction. Higher rotational states of the (001) vibration, if formed in H+NO+M reaction, most probably suffer rapid losses to X 1A′ state by internal conversion. The lower energy content of HNO* formed in H+(NO)2 reaction suppresses this internal conversion and hence the relative population of the (001) state becomes large. The reaction probability was also measured as a function of collision energy and the result indicates the absence of the reaction barrier.