On the chemiluminescent reaction Cl + + H 2→HCl +(A 2Σ +) + H

Abstract

The chemiluminescent reaction Cl ++H 2(X 1Σ + g)→H( 2S g)+HCl +(A 2Σ +) has been observed in an ion—molecule scattering experiment. This was achieved by detection of the spontaneous optical emission of the HCl +(A 2Σ +, ν′=0→X 2Π i, ν″=0) band in the wavelength region between 3500 and 3650 Å. The reaction produces only a very low luminescence intensity, from which a cross section of the order of 4×10 −3 Å 2 was estimated. This small cross section could be explained qualitatively by means of an ab initio correlation diagram of the H 2Cl + collision complex, which shows that only a small fraction of the ions of the entrance channel will react into the observed product state.