Thermal rate constants for the O(3P) + HBr and O(3P) + DBr reactions: transition-state theory and quantum mechanical calculations.
The O((3)P) + HBr → OH + Br and O((3)P) + DBr → OD + Br reactions are studied on a recent high-quality ab initio-based potential energy surface. Thermal rate constants over the 200-1000 K temperature range, calculated using variational transition-state theory (VTST) with the small-curvature tunneling (SCT) correction and quantum mechanical methods with the J-shifting approximation (QM/JS) for zero total angular momentum (J = 0), are reported. These results are compared to the available experimental data, which lie in the ranges of 221-554 and 295-419 K for O + HBr and O + DBr, respectively. The rate constants, in cm(3) molecule(-1) s(-1) and at 298 K, for the O + HBr reaction are 3.66 × 10(-14) for VTST, 3.80 × 10(-14) for QM/JS, and 3.66 × 10(-14) for the average of eight experimental measurements.
Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo , Av. Prof. Lineu Prestes 748, São Paulo 05508-000, Brazil.
Antonio G S
AG
de Oliveira-Filho
Fernando R
FR
Ornellas
Kirk A
KA
Peterson
Steven L
SL
Mielke