Matrix isolation study of the photochemically induced reaction of ozone with dibromochloromethane and bromodichloromethane in solid argon at 14 K. FT-IR spectra of the complexes C(O)HCl· · ·BrX, C(O)HBr· · ·XCl, C(O)BrCl· · ·HX, (OC)(HCl)(Br2), (OC)(HBr)(Cl2), and (OC)(BrCl)(HX) (where X = Br or Cl)

Abstract

Quartz-filtered (λ > 240 nm) photolysis of either ozone/dibromochloromethane or ozone/bromodichloromethane in an argon matrix at 14 K has been shown by FT-IR spectroscopy to lead to the formation of the carbonyl· · ·Lewis acid complexes C(O)HCl· · ·BrX, C(O)HBr· · ·XCl, C(O)BrCl· · ·HX, and C(O)Cl₂· · ·HBr, where X = Br or Cl, depending on the trihalogenomethane used. Several of these complexes are new and are formed by either hydrogen halide or dihalogen abstraction reactions. Upon further irradiation the carbonyl complexes dissociate to form the new carbon monoxide complexes (OC)(HCl)(Br₂), (OC)(HBr)(Cl₂), and (OC)(BrCl)(HX). Thus the photo-induced reactions of ozone with trihalogenomethanes lead to the formation of new carbonyl and carbon monoxide complexes whose vibrational properties are well characterised by FT-IR spectroscopy. Suggested pathways for the photolyses are presented.