Experimental and theoretical study on the reaction of CCl2+H2O

Absolute rate constant for the reaction of CCl2 radical with H2O is obtained as (5.45 +/- 0.95) x 10(-14) cm(3) (.) molecule(-1) (.) s(-1) by LP-LIEF technique. The CCl2 is first produced by 213 run laser photolysis of CCl4. The mechanism for the reaction CCl2 + H2O has been studied using a high-level ab initio G2MP2 method. It is found that there are two reaction mechanisms: insertion and addition-elimination. The three primary product channels, HCl + HClCO, HCl + trans-ClCOH and HCl + cis-ClCOH, are studied in detail. Moreover, the branch ratios are calculated using RRKM-TST and convention transition state theories. The calculations show that at lower temperatures the major product channel is HCl + HCClO via the insretion of C atom of CCl2 into OH bond of H2O, whereas the formation of HCl + trans-ClCOH dominates at higher temperatures.