Existence of a Chlorine Oxide and Water (ClO·H_2O) Radical Complex

摘要

Several mechanisms have been proposed to explain ozone depletion in the Antarctic stratosphere. However, most of the catalytic ozone removal processes that have been suggested to date involve ClO. There are two critical steps in these mechanisms: (1) the formation of the ClO dimer and (2) its photodecomposition. The formation of the ClO dimer (reaction 1) requires the presence of a third body to stabilize the dimer; consequently the rates for dimer formation are slow. The ClO + ClO + M → Cl_2O_2 + M (1) question we raise is whether there is a possible chaperone for ClO that could enhance the dimer formation rate. Schaefer and co-workers and Nanayakkara et al. noted the existence of a hydroxyl radical-water complex that is bound by 5.6 kcal mol~(-1). A ClO·H_2O radical complex could play a role in enhancing the dimer formation by acting as a chaperone through ClO·H_2O + ClO → Cl_2O_2 + H_2O (2) In this paper, we use ab initio calculations to determine if a radical complex exists.