Yang Ming-Chung, Zhang Zheng-Feng, Su Ming-Der
Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan.
Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
Inorg Chem. 2022 Aug 22;61(33):12959-12976. doi: 10.1021/acs.inorgchem.2c00259. Epub 2022 Aug 5.
The reactions of CS captured by intramolecular geminal G13/P-based (G13 = group 13 elements) and Ga/G15-based (G15 = group 15 elements) frustrated Lewis pairs have been theoretically examined by using density functional theory (DFT) computations. With regard to the nine FLP-related compounds, our DFT calculated results reveal that only and can kinetically and thermodynamically precede the energetically feasible combination reactions with CS to form the five-membered heterocyclic adducts. Our activation strain model analyses on the nine aforementioned model molecules indicate that the atomic radius of the Lewis acceptor (G13) and the Lewis donor (G15) plays a role in controlling their barrier heights to obtain good orbital overlaps among , , and CS. Our theoretical observations based on the energy decomposition analysis-natural orbitals for chemical valence (EDA-NOCV) approach strongly indicate that the donor-acceptor bonding (i.e., singlet-singlet bonding) rather than the electron-sharing bonding (i.e., triplet-triplet bonding) plays a central role in determining the bonding conditions of the transition states, and . In addition, the theoretical evidence obtained by the frontier molecular orbital theory and EDA-NOCV analyses reveals that the best description for the bonding natures of the combination reactions of intramolecular geminal and with CS is the lone pair(G15) → p-π*(C) interaction rather than the p-π*(G13) ← p-π(S) interaction. Moreover, our present DFT computations concerning the calculated structures and corresponding relative energetics of the stationary points connected with the aforementioned sophisticated approaches are in accordance with the Hammond postulate.
通过密度泛函理论（DFT）计算，从理论上研究了分子内偕位G13/P基（G13 = 第13族元素）和Ga/G15基（G15 = 第15族元素）受阻路易斯对捕获CS的反应。对于九种与FLP相关的化合物，我们的DFT计算结果表明，只有 和 能够在动力学和热力学上优先于与CS发生能量上可行的组合反应，形成五元杂环加合物。我们对上述九个模型分子的活化应变模型分析表明，路易斯受体（G13）和路易斯供体（G15）的原子半径在控制它们的势垒高度方面发挥作用，以便在 、 和CS之间获得良好的轨道重叠。我们基于能量分解分析 - 化学价自然轨道（EDA - NOCV）方法的理论观察强烈表明，供体 - 受体键合（即单重态 - 单重态键合）而非电子共享键合（即三重态 - 三重态键合）在确定过渡态 和 的键合条件中起核心作用。此外，通过前沿分子轨道理论和EDA - NOCV分析获得的理论证据表明，对分子内偕位 和 与CS组合反应的键合性质的最佳描述是孤对电子（G15）→p - π*（C）相互作用，而非p - π*（G13）←p - π（S）相互作用。此外，我们目前关于与上述复杂方法相关的驻点的计算结构和相应相对能量的DFT计算符合哈蒙德假设。
