Matrix infrared study of O-initiated atomic oxidation of CH3Cl:: Identification of the triplet CH3Cl•••O complex

Infrared spectroscopic studies have been conducted on the products of the reaction between atomic oxygen in its ground and excited states with normal and isotopically substituted methyl chloride in argon matrixes at 11 K. With the O(D-1) atom, the major product is the hydrogen-bonded complex between formaldehyde and hydrogen chloride. Abstraction of a hydrogen atom from CH3Cl by O(D-1) appears as a minor channel. Small amounts of HClCO were also found. Formation of CO-HCl as a secondary and primary product was observed. Reaction of CH3Cl with the O(P-3) atom was evidenced. Spectra suggest the formation of a collision complex CH3Cl ... O formed by addition of an oxygen atom to CH3Cl. Ab initio calculations about the structure and vibrational spectrum of the CH3ClO singlet and CH3Cl ... O triplet are reported.