Reaction with ozone vibrationally excited, production

Reactions with Ozone. Many reactions of atoms with endothermic compounds, such as ozone, OOO, NCI3, and the azides of chlorine and bromine, have been found to be excellent sources of radicals, often in a state of high vibrational excitation of product. The stratospherically important reactions of halogen atoms and ozone (see Section 5) have recently received wide attention in a number of laboratories. 

A chemically based, mass-independent fractionation process was first observed during ozone formation through the gas-phase recombination reaction (Thiemens Heidenreich 1983) O + O2 + M - O3 + M. The product ozone possesses equally enriched heavy-oxygen isotopes I7 IS0. by approximately lOO /oo with respect to the initial oxygen, with a slope value of unity in a three-isotope oxygen plot. This discovery led to the conclusion that a symmetry-dependent reaction can produce meteoritic isotopic anomalies (Thiemens 1999, 2006). Recently, theoretical calculations of Gao Marcus (2001) established the major role of symmetry in isotopolog-specific stabilization of vibrationally excited ozone molecules that give rise to the mass-independent compositions. 

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