Department of Applied Chemistry, National Chiayi University, Chiayi60004, Taiwan.
Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung80708, Taiwan.
Inorg Chem. 2023 Jan 16;62(2):1018-1031. doi: 10.1021/acs.inorgchem.2c03968. Epub 2023 Jan 5.
The trapping reactions of by benzene-bridged Group-13/P-based and B/Group-15-based frustrated Lewis pairs (FLPs) have been computationally investigated based on density functional theory. Interestingly, our theoretical calculations predict that the capture of by all five Group-13/P-based FLPs is energetically feasible. However, in the B/Group-15-based FLPs, only the phosphorus-based B/P-FLP can trap from kinetic and thermodynamical viewpoints. According to the analyses of the activation strain model, it can be known that the atomic radius of the G15 element (Lewis base) of benzene-bridged B/Group-15-FLP plays an important role in controlling the reactivity of the catching reactions, whereas the atomic radius of the Group-13 center (Lewis acid) does not play a role in influencing the activation barrier of these catching reactions. Our theoretical findings based on sophisticated methods suggest that the forward bonding is the FLP-to- interaction, the LP (Group-15-donor) → vacant p-π-orbital (), which was quantitatively proved to be strong in such present catching reactions. However, the back bonding is the -to-FLP interaction, the empty σ-orbital (Group-13-acceptor) ← sp-σ-orbital (), which was verified to be relatively weak. Our theoretical pieces of evidence reveal that the stronger electron-donating ability of the substituents is attached to the Lewis basic center and can make the reaction barrier of the benzene-bridged Group-13/Group-15-based FLP-related compound catching smaller and more exothermic.
基于密度泛函理论，研究了由苯桥联第 13 族/P 基和 B/第 15 族基受阻路易斯对（FLP）引发的捕获反应。有趣的是，我们的理论计算预测，所有 5 种第 13 族/P 基 FLP 都可以捕获。然而，在 B/第 15 族基的 FLP 中，只有磷基 B/P-FLP 可以从动力学和热力学的角度捕获。根据活化应变模型的分析，可以知道苯桥联 B/第 15 族-FLP 的 G15 元素（路易斯碱）的原子半径在控制捕获反应的反应性方面起着重要作用，而第 13 族中心（路易斯酸）的原子半径在影响这些捕获反应的活化能垒方面不起作用。我们基于复杂方法的理论发现表明，正向成键是 FLP-相互作用，LP（第 15 族供体）→空 p-π-轨道（），这在目前的捕获反应中被证明是很强的。然而，反向成键是-至-FLP 相互作用，空的σ-轨道（第 13 族受体）←sp-σ-轨道（），这被证明是相对较弱的。我们的理论证据表明，路易斯碱性中心上的取代基具有更强的供电子能力，可以使苯桥联第 13 族/第 15 族基 FLP 相关化合物捕获的反应能垒更小，放热更多。
