Activation of Strong Boron－Fluorine and Silicon－Fluorine sigma-Bonds: Theoretical Understanding and Prediction
Activation of Strong Boron－Fluorine and Silicon－Fluorine sigma-Bonds: Theoretical Understanding and Prediction
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强硼－氟和硅－氟西格玛键的活化：理论理解和预测
DOI：
10.1002/chem.201502197
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Shigeyoshi Sakaki
中科院分区：
文献类型：
--
作者：
Hajime Kameo;Shigeyoshi Sakaki
用密度泛函方法研究了BF 3与铂（0）双膦配合物[Pt（PMe 3）2]（1）的氧化加成反应. BF 3与1的氧化加成反应的这两种方式都是吸能的（ΔG°分别为26.8和35.7 kcal mol−1），并且需要很大的吉布斯活化能（ΔG°分别为56.3和38.9 kcal mol−1）。 第二个硼烷在加速活化过程中起着至关重要的作用;在第二个BF 3分子存在的情况下，BF 3与1发生了氧化加成，ΔG°和ΔG°值分别为10.1和−4.7 kcal mol−1。 ΔG° θ变得非常小，ΔG°变为负值。电荷转移（CT），F→ BF 3，发生从游离的氟化物到第二个非配位的BF 3。这种CT相互作用稳定了过渡态和产物。第二硼烷的参与加速了BF 2ArF（ArF= 3，5-双（三氟甲基）苯基）的B-F σ-键断裂和BCl 3的B-Cl σ-键断裂。计算结果表明，在第二个SiF 4分子的存在下，SiF 4与1之间容易发生氧化加成反应，生成高价Si.
The oxidative addition of BF3to a platinum(0) bis(phosphine) complex [Pt(PMe3)2] (1) was investigated by density functional calculations. Both thecisandtranspathways for the oxidative addition of BF3to1are endergonic (ΔG°=26.8 and 35.7 kcal mol−1, respectively) and require large Gibbs activation energies (ΔG°≠=56.3 and 38.9 kcal mol−1, respectively). A second borane plays crucial roles in accelerating the activation; thetransoxidative addition of BF3to1in the presence of a second BF3molecule occurs with ΔG°≠and ΔG° values of 10.1 and −4.7 kcal mol−1, respectively. ΔG°≠becomes very small and ΔG° becomes negative. A charge transfer (CT), F→BF3, occurs from the dissociating fluoride to the second non‐coordinated BF3. This CT interaction stabilizes both the transition state and the product. The BF σ‐bond cleavage of BF2ArF(ArF=3,5‐bis(trifluoromethyl)phenyl) and the BCl σ‐bond cleavage of BCl3by1are accelerated by the participation of the second borane. The calculations predict thattransoxidative addition of SiF4to1easily occurs in the presence of a second SiF4molecule via the formation of a hypervalent Si species.