ABSOLUTE DETERMINATION OF THE DECOMPOSITION PATHWAYS OF ELECTRONIC CHEMICALLY ACTIVATED METHANOL

Electronic chemically activated methanol was produced in a quasistatic cell in the reaction O(D-1) + CH4((X) over tilde(1)A(1)) --> CH3OH((X ) over tilde(1)A)(double dagger) at room temperature and pressures in the range 0.5 less than or equal to p/mbar less than or equal to 105. The absolute concentrations of the products CH2O, CH2((a) over tilde), OH, and O(P-3) were determined with the laser-induced fluorescence (L IF) method. The following product ratios were determined: Phi(OH) = 0. 90 (+0.1, -0.2); Phi(CH2O) = 0.06 +/- 0.01; Phi(CH2((a) over tilde) = 0.02 +/- 0.01; Phi(O(P-3)) = 0.02 +/- 0.01. The concentration profiles of the products CH2O and CH2((a) over tilde) are in agreement with an overall rate constant of reaction 1 of k(1) = (9 +/- 2) x 10(13)cm(3) /mol s, proving CH2O and CH2((a) over tilde) to be primary products of reaction 1. The bending mode in CH2((a) over tilde) was found to be e xcited up to v''(2)= 1. If the reaction proceeds completely via insert ion of the O(D-1) into the C-H bond, the initially formed complex CH3O Hdouble dagger decomposes with a product distribution which is nonstat istical,i.e., prior to energy randomization.