Experimental and theoretical investigation of the reaction
نویسنده
چکیده
The rate coefficient of the reaction NHsX 3S−d+Hs2Sd→ k1a NsSd+H2sX Sg d is determined in a quasistatic laser-flash photolysis, laser-induced fluorescence system at low pressures s2 mbarø p ø10 mbard. The NHsXd radicals are produced via the quenching of NHsaDd sobtained by photolyzing HN3d with Xe whereas the H atoms are generated in a H2/He microwave discharge. The NHsXd concentration profile is measured under pseudo-first-order condition, i.e., in the presence of a large excess of H atoms. The room temperature rate coefficient is determined to be k1a = s1.9±0.5d31012 cm3 mol−1 s−1. It is found to be independent of the pressure in the range considered in the present experiment. A global potential energy surface for the A9 state is calculated with the internally contracted multireference configuration interaction method and the augmented correlation consistent polarized valence quadruple zeta atomic basis. The title reaction is investigated by classical trajectory calculations on this surface. The theoretical room temperature rate coefficient is k1a=0.92310 12cm3 mol−1 s−1. Using the thermodynamical data for the atoms and molecules involved, the rate coefficient for the reverse reaction, k−1a, is also calculated. At high temperatures it agrees well with the measured k−1a. © 2005 American Institute of Physics. fDOI: 10.1063/1.1862615g
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