ATMOSPHERIC CHEMISTRY OF THE REACTION CLO--]CLO.O2 - WHERE IT STANDS,WHAT NEEDS TO BE DONE, AND WHY(O2[)

Possible existence and chemistry of ClO . O2 was originally proposed t o explain the Norrish-Neville effect that O2 suppresses chlorine photo sensitized loss of ozone. It was also thought that ClO . O2 might have some atmospheric chemistry significance. Recently, doubts have been c ast on this proposal, because certain laboratory data seem to imply th at the equilibrium constant of the title reaction is so small that ClO . O2 may be too unstable to matter. However, those data create only a superficial illusion to that effect, because on a closer analysis the y do not disprove a moderately stable and chemically significant ClO . O2. Furthermore, our state-of-the-science accurate computational chem istry calculations also suggest that ClO . O2 may be a weakly bound C1 OOO radical with a reactive 2A ground electronic state. There is there fore a need to design and perform definitive experimental tests of the existence and chemistry of the ClO . O2 species, which we discuss and which have the potential to mediate the chlorine-catalyzed stratosphe ric ozone depletion.