## Abstract

The unimolecular decomposition of HClO_{4} has been investigated at the G2M//B3LYP/6-311 + G(3df, 2p) level of theory. Above 500 K, the decomposition process was found to depend strongly on pressure below 200 atm. The rate constants at the high- and low-pressure limits were predicted to be k_{1} ^{∞} = 1.5 × 10^{17} exp(-26500/T) s^{-1} and k_{1} ^{0} = 3.39 × 10^{30} T^{-10.9} exp(-29430/T) cm^{3} molecule^{-1} s ^{-1}, respectively. Under the atmospheric-pressure condition, the predicted first-order rate coefficient for the temperature range 300-3000 K, k_{1} = 5.0 × 10^{51} T^{-11.64} exp(-30700/T) s^{-1}, agrees reasonably with experimental data obtained at 550-750 K by different experimental groups. We have also calculated the rate constants for the bimolecular reaction of OH with ClO_{3} producing HClO_{4} by association/stabilization and HO_{2} + ClO_{2} by association/fragmentation. At the high-pressure limit, the rate constants can be given as:k_{-1} = 3.2 × 10^{-10} T^{0.07} exp(-25/T) cm^{3} molecule^{-1} s^{-1} and k_{2} = 2.1 × 10^{-10} T^{0.09} exp(-18/T) cm^{3} molecule^{-1} s^{-1}, respectively, for the temperature range 300-3000 K. Under the atmospheric pressure condition, the OH + ClO_{3} reaction produces predominately the HO_{2} + ClO_{2} products.

Original language | English |
---|---|

Article number | 25 |

Pages (from-to) | 1-6 |

Number of pages | 6 |

Journal | PhysChemComm |

Volume | 4 |

DOIs | |

State | Published - 13 Dec 2001 |