Escobar Roberto, Meza Jessica, Pena Javier, Atesin Abdurrahman C, Jones William D, Müller Christian, Ateşin Tülay A
School of Integrative Biological and Chemical Sciences, The University of Texas Rio Grande Valley, Edinburg, Texas 78541, United States.
Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.
Inorg Chem. 2024 Sep 9;63(36):16622-16630. doi: 10.1021/acs.inorgchem.4c01194. Epub 2024 Aug 28.
The density functional theory study of the thermal C-C reductive coupling from terminal cyanido and hypothetical cyaphido complexes of [Ni(dmpe)] (dmpe = 1,2-bis(dimethylphosphino)ethane) revealed the key reaction intermediate in the reductive C-CP coupling being a σ-CC complex unlike an η-aryl complex in the Ni C-CN system, as already observed in our previous studies. The reaction in THF is endothermic by 4.9 kcal/mol for cyanido with a 32.0 kcal/mol activation barrier and exothermic by 28.5 kcal/mol for cyaphido with an 11.3 kcal/mol activation barrier. To compare our results with the existing experimental data, we chose mesityl as the aryl group and also studied the CP reaction with [Pt(dmpe)] and [Pt(dmpm)] (dmpe = 1,2-bis(dimethylphosphino)methane) fragments. Our findings are consistent with the thermodynamically uphill photolytic C-CP bond activation in phosphaalkynes with Pt and a faster thermal back-reaction with [Pt(dmpe)] compared to that of [Pt(dmpm)]. Based on the natural population analysis, when the polarity of the C-C bond is inverted, the sign of Δ is also inverted.
对[Ni(dmpe)]（dmpe = 1,2 - 双（二甲基膦基）乙烷）的末端氰基和假设的氰磷基配合物之间热C-C还原偶联的密度泛函理论研究表明，与我们之前研究中已观察到的Ni - C-CN体系中的η - 芳基配合物不同，还原C-CP偶联中的关键反应中间体是σ - CC配合物。在四氢呋喃中，氰基反应吸热4.9千卡/摩尔，活化能垒为32.0千卡/摩尔；氰磷基反应放热28.5千卡/摩尔，活化能垒为11.3千卡/摩尔。为了将我们的结果与现有实验数据进行比较，我们选择均三甲苯基作为芳基，并研究了与[Pt(dmpe)]和[Pt(dmpm)]（dmpe = 1,2 - 双（二甲基膦基）甲烷）片段的CP反应。我们的研究结果与磷炔中与Pt发生的热力学上向上的光解C-CP键活化以及与[Pt(dmpe)]相比[Pt(dmpm)]更快的热逆反应一致。基于自然布居分析，当C-C键的极性反转时，Δ的符号也会反转。
