氟氯酰与丙烷反应的密度泛函理论研究

Theoretical Study on the Reaction of Chlorine Trifluoride Oxide with Propane by Density Functional Theory

应用密度泛函理论(DFT),对氟氯酰(ClF3O)引发丙烷(C3H8)反应生成C3H7自由基或丙醇等产物的机理进行了研究.在B3PW91/6-311++G(d,p)水平上优化了9个不同反应通道上各驻点物(反应物、中间体、过渡态和产物)的几何构型,并计算了它们的振动频率和零点振动能.通过零点能校正计算了各反应路径的活化能,并应用过渡态理论计算了各反应路径常温下的速率常数k.计算结果表明:ClF3O与C3H8反应可经过不同路径生成HF,C3H7自由基和C1F2O自由基或C3H7OH和ClF3.其中,最可几反应路径为ClF3O分子的中间位F原子进攻丙烷β位H原子的反应,活化能仅为7.54kJ/mol,速率常数为0.153×106mol-1·dm3·s-1.

Using the density functional theory （DFT）, the reaction mechanism of ClF3O and C3H8 to produce propane radical or propane was studied. At B3PW91/6-311＋＋G（d,p） level, the geometries of all species （reactants, intermediates, transition states and products） of 9 different reaction paths were optimized and the vibration frequencies as well as zero point vibration energies （ZPVE） were also calculated. The activation energies of the reactions were calculated with the results of ZPVE, and the reaction constants, using transition state theory, at room temperature and standard concentration were also calculated. The calculated results suggest that the reaction of ClF3O and C3H8 can produce C3H7 radical, HF and C1F2O or produce C3H7OH and ClF3 through different paths. The main path of the reaction is ClF3O＋C3H8→TS4→M2＋ HF＋ClF2O with the activation energy only 7.54 kJ/mol and reaction constant k4=0.153×106 mol-1·dm3·s-1.