Kinetics and Mechanism of the Reaction of O(3P) with Carbon Monoxide

摘要

The mercuryhyphen;photosensitized decomposition of N2O to produce O(3P) was studied in the presence of mixtures of CO and 2hyphen;trifluoromethylpropene (TMP) at 298, 383, and 472deg;K to determine the relative rate constants for the reaction of O(3P) with the two gases. The absolute value of the rate constant with TMP was found to be9.1 times; 109thinsp;explpar;minus;2,200sol;RTrpar;Mminus;1.secminus;1from a similar competitive study at the same temperatures between TMP and butenehyphen;1, whose rate constant with O(3P) is relatively well known. The absolute value for the O(3P)plus;CO reaction was thus determined, and it was found to depend on pressure. The reaction was intermediate between second and third order. For any pressure, the reaction became more nearly second order as the temperature was raised. Expressions were obtained for the limiting lowhyphen;and highhyphen;pressure rate constants:k0equals; 5.9 times; 109thinsp;explpar;minus;4100sol;RTrpar;Mminus;2.secminus;1with N2O as a chaperone andkinfin;equals; 1.6 times; 107thinsp;explpar;minus;2900sol;RTrpar;Mminus;1.secminus;1. These results were interpreted in terms of the mechanism:Olpar;3Prpar;plus;COplus;Mrlarr2;minus;aaCO2lpar;3B2rpar;plus;MCO2lpar;3B2rpar;rlarr2;minus;bbCO2lpar;1B2rpar;,CO2lpar;1B2rpar;plus;Mrarr;cCO2lpar;1Sgr;gplus;rpar;plus;M,withk0equals;kathinsp;andthinsp;kinfin;equals;kakbsol;kminus;a. The results are compared and correlated with the findings of other investigations.