Infrared Spectrum of the Nitrosyl Chloride Monomer and Dimer in Solid Nitrogen: Temperature-Induced Mobility of Nitrosyl Chloride

Abstract

Experimental investigations at different temperatures of the infrared spectra of nitrosyl chloride trapped in a nitrogen matrix allow identification of the ClNO dimer and a next nearest neighbor pair. At 21 K, the pair transforms irreversibly in monomer and also in dimer according to the ClNO initial concentration, whereas at 26 K, the monomer transforms to dimer. On the basis of kinetic studies, these observations have been interpreted by the existence of two distinct motions of the ClNO molecule in the nitrogen matrix: the first at short range with an activation energy of around 4 kJ mol-1, and the second at long range leading to the formation of (ClNO)2 with an activation energy of around 7.5 kJ mol-1.