| Autor: |
Yamada, Takahiro, Taylor, Philip H., Goumri, A., Marshall, Paul |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 11/22/2003, Vol. 119 Issue 20, p10600-10606, 7p, 2 Charts, 4 Graphs |
| Abstrakt: |
The pulsed laser photolysis/pulsed laser-induced fluorescence technique has been applied to obtain rate coefficients for OH+CH[sub 3]C(O)CH[sub 3] and CD[sub 3]C(O)CD[sub 3] of k[sub H](298–832 K)=(3.99±0.40)×10[sup -24]T[sup 4.00] exp(453±44)/T and k[sub D](298–710 K)=(1.94±0.31)×10[sup -21]T[sup 3.17] exp(-529±68)/T cm[sup 3] molecule[sup -1] s[sup -1], respectively. Three pathways were characterized via the CBS–QB3 ab initio method to obtain complete basis set limits for coupled-cluster theory. Addition to form CH[sub 3]C(O)(OH)CH[sub 3], followed by dissociation to CH[sub 3]+CH[sub 3]C(O)OH, is negligibly slow. Variational transition state theory reveals that the dominant products are CH[sub 3]C(O)CH[sub 2]+H[sub 2]O formed by direct abstraction at higher temperatures and via a hydrogen-bonded complex below about 450 K. Inclusion of tunneling gives good accord with the observed kinetic isotope effect down to about 250 K. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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