Rate Coefficient for the 4Heμ + CH4 Reaction at 500 K: Comparison between Theory and Experiment
Rate Coefficient for the 4Heμ + CH4 Reaction at 500 K: Comparison between Theory and Experiment
复制标题
500 K 下 4Heμ CH4 反应的速率系数：理论与实验的比较
DOI：
10.1021/acs.jpcb.5b08368
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发表时间：
2016
影响因子：
3.3
通讯作者：
Guo Hua
中科院分区：
文献类型：
--
作者：
Arseneau Donald J.;Fleming Donald G.;Li Yongle;Li Jun;Suleimanov Yury V.;Guo Hua
报道了500 K下氦μ原子从甲烷中抽氢反应Heμ + CH 4 → HeμH + CH 3的速率常数，并与理论进行了比较，为多原子甲烷反应体系的势能面和反应速率理论提供了重要的检验.用于表征该反应的理论包括变分过渡态（CVT/μOMT）理论（VTST）和环聚合物分子动力学（RPMD）对最近开发的PES的计算，并与早期对H，D和Mu + CH 4反应的不同PES的计算进行了比较，特别是后者，提供了36倍的原子质量变化。虽然严格的量子计算已经进行了H + CH 4反应，这些尚未扩展到该反应的同位素体（与H3相反），所以重要的是提供测试的动力学同位素效应相比，不太严格的理论通过实验测量。在这方面，VTST和RPMD计算的Heμ + CH 4反应的速率常数与实验在500 K时的吻合度非常好，在两种情况下都在10%以内，这与实验误差重叠。
The rate constant for the H atom abstraction reaction from methane by the muonic helium atom, Heμ + CH4→ HeμH + CH3, is reported at 500 K and compared with theory, providing an important test of both the potential energy surface (PES) and reaction rate theory for the prototypical polyatomic CH5reaction system. The theory used to characterize this reaction includes both variational transition-state (CVT/μOMT) theory (VTST) and ring polymer molecular dynamics (RPMD) calculations on a recently developed PES, which are compared as well with earlier calculations on different PESs for the H, D, and Mu + CH4reactions, the latter, in particular, providing for a variation in atomic mass by a factor of 36. Though rigorous quantum calculations have been carried out for the H + CH4reaction, these have not yet been extended to the isotopologues of this reaction (in contrast to H3), so it is important to provide tests of less rigorous theories in comparison with kinetic isotope effects measured by experiment. In this regard, the agreement between the VTST and RPMD calculations and experiment for the rate constant of the Heμ + CH4reaction at 500 K is excellent, within 10% in both cases, which overlaps with experimental error.