Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, PR China.
Phys Chem Chem Phys. 2010 Sep 28;12(36):10846-56. doi: 10.1039/c004284f. Epub 2010 Jul 26.
Singlet and triplet potential energy surfaces for the reactions of oxygen atoms ((3)P and (1)D) with CF(3)CN have been studied computationally to evaluate the reaction mechanisms, possible products, and rate constants. On the triplet surface, six kinds of pathway are revealed, namely: direct fluorine abstraction, C-addition/elimination, N-addition/elimination, substitution, insertion and F-migration. The results show that the reaction should occur mainly through the C-addition/elimination mechanism involving the chemically activated CF(3)C(O)N* intermediate, and the major products are CF(3) and NCO. The rate constants for C-addition/elimination channel of the reaction of O((3)P) with CF(3)CN have been determined by using RRKM statistical rate theory and compared with the experimental data. On the singlet surface, the atomic oxygen can easily insert into the C-F or C-C bond of CF(3)CN, forming the insertion intermediates FOCF(2)CN and CF(3)OCN, and O((1)D) can add to the carbon or nitrogen atom of the CN group in CF(3)CN, forming the addition intermediates CF(3)C(O)N and CF(3)CNO; both approaches are found to be barrierless. The decomposition and isomerization of some intermediates were also modeled at the QCISD(T)/6-311+G(2df)//B3LYP/6-311+G(d) level for the better understanding of the O((1)D) with CF(3)CN chemistry. The decomposition products CF(3) and NCO arising from CF(3)OCN and CF(3)NCO are the dominant species. Further comparison with similar reactions is also summarized.
已通过计算研究了氧原子((3)P 和 (1)D)与 CF(3)CN 反应的单重态和三重态势能面，以评估反应机理、可能的产物和速率常数。在三重态表面上，揭示了六种途径，即：直接氟提取、C-加成/消除、N-加成/消除、取代、插入和 F-迁移。结果表明，反应应主要通过涉及化学激活的 CF(3)C(O)N*中间体的 C-加成/消除机制发生，主要产物为 CF(3)和 NCO。通过 RRKM 统计速率理论确定了 O((3)P)与 CF(3)CN 反应的 C-加成/消除通道的速率常数，并与实验数据进行了比较。在单重态表面上，氧原子很容易插入 CF(3)CN 的 C-F 或 C-C 键，形成插入中间体 FOCF(2)CN 和 CF(3)OCN，并且 O((1)D)可以加成到 CF(3)CN 的 CN 基团的碳原子或氮原子上，形成加成中间体 CF(3)C(O)N 和 CF(3)CNO；两种方法都被发现是无势垒的。为了更好地了解 O((1)D)与 CF(3)CN 的化学性质，还在 QCISD(T)/6-311+G(2df)//B3LYP/6-311+G(d)水平上对一些中间体的分解和异构化进行了建模。由 CF(3)OCN 和 CF(3)NCO 产生的分解产物 CF(3)和 NCO 是主要产物。还总结了与类似反应的进一步比较。
