## 摘要

The kinetics for the metathetical reactions of phenyl radical with toluene and xylenes have been studied experimentally and theoretically. The absolute bimolecular rate constants for the reactions of C_{6}H_{5} with toluenes (C_{7}H_{8} and C_{7}D_{8}) and xylenes (three C_{8}H_{10} isomers) were measured by cavity ringdown spectrometry at temperatures between 295 and 483 K. For the reaction with toluene, a strong isotope effect was observed, whereas for xylene reactions no structural preference was noticed among the three isomers. The weighted least-squares analysis of each reaction gave rise to the following rate constant expressions in units of cm^{3}/(mol s): k(C_{7}H_{8}) = (2.08 ± 0.11) × 10^{11} exp[-(1027 ± 35)/T]; k(C_{7}D_{8}) = (2.27 ± 0.43) × 10^{11} exp[-(1340 ± 64)/T]; k(C_{8}H_{10}) = (1.48 ± 0.11) × 10^{11} exp[-(526 ± 27)/T]. Additionally, we have carried out hybrid density functional theory (B3LYP) calculations for the reactions of C_{7}H_{8} and C_{7}D_{8} using the 6-31G-(d,p) basis set. The predicted rate constants using the conventional transition state theory with the calculated vibrational frequencies and moments of inertia fit well to the experimental results with only minor adjustments in the calculated reaction barriers. Combination of our low-temperature C_{7}H_{8} kinetic data with those obtained at high temperatures in shock waves gave the expression k(C_{7}H_{8}) = (4.15 × 10^{-3})T^{4.5} exp(800/T) cm^{3}/(mol s) for the temperature range 300-1450 K.

原文 | English |
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頁（從 - 到） | 4002-4008 |

頁數 | 7 |

期刊 | Journal of Physical Chemistry A |

卷 | 103 |

發行號 | 20 |

DOIs | |

出版狀態 | Published - 20 5月 1999 |

## 指紋

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_{5}radical reactions with toluene and xylenes by cavity ringdown spectrometry」主題。共同形成了獨特的指紋。