Ye Jin-Ting, Bai Feng-Yang, Shi Shao-Qing, Pan Xiu-Mei
Institute of Faculty of Chemistry, National & Local United Engineering Lab for Power Battery Northeast Normal University, 130024 Changchun, People's Republic of China.
Institute of Faculty of Chemistry, National & Local United Engineering Lab for Power Battery Northeast Normal University, 130024 Changchun, People's Republic of China.
J Mol Graph Model. 2017 Mar;72:156-167. doi: 10.1016/j.jmgm.2017.01.002. Epub 2017 Jan 6.
The NO-initiated reactions of CHOCH and CHOCHCH have been investigated by the BHandHLYP method in conjunction with the 6-311G(d,p) basis set. Thermodynamic and kinetic data are further refined using the comparatively accurate CCSD(T) method. According to the values of reaction enthalpies (ΔH) and reaction Gibbs free energies (ΔG) from CHOCHCH with NO system, we find that H-abstraction pathway from the α-CH group is more exothermic. It is further confirmed by the calculated CH bond dissociation energy of CHOCHCH molecule. All the rate constants, computed through means of canonical variational transition state with small-curvature tunneling correction, are fitted to the three-parameter expressions k=1.54×10Texp(-1035.53/T) and k=3.55×10Texp(-281.24/T)cmmolecules and branching ratios are computed over the temperature range 200-600K. The branching ratios are also discussed. The atmospheric lifetimes of CHOCH and CHOCHCH determined by the NO radical are about 270 and 29days, respectively.
采用BHandHLYP方法结合6-311G(d,p)基组对CHOCH和CHOCHCH与NO引发的反应进行了研究。使用相对精确的CCSD(T)方法进一步优化了热力学和动力学数据。根据CHOCHCH与NO体系的反应焓（ΔH）和反应吉布斯自由能（ΔG）值，我们发现从α-CH基团夺取氢的途径放热更多。CHOCHCH分子的计算碳氢键解离能进一步证实了这一点。通过具有小曲率隧道效应校正的正则变分过渡态方法计算得到的所有速率常数，拟合为三参数表达式k = 1.54×10Texp(-1035.53/T)和k = 3.55×10Texp(-281.24/T) cm分子，并计算了200 - 600K温度范围内的分支比。还讨论了分支比。由NO自由基测定的CHOCH和CHOCHCH的大气寿命分别约为270天和29天。
