近年来,硫属元素中心之间的非共价相互作用引起了大量的研究兴趣,因为它们在有机催化中的潜在应用,材料科学,药物设计,生物系统,晶体工程,和分子识别。然而,文献中很少报道关于π孔型硫属元素的研究。在这里,XO2之间形成的模型复合物中的π-空穴型分子间硫属元素相互作用(X=S,Se,Te)和CH3YCH3(Y=O,S,Se,Te)通过量子化学计算进行了系统研究。模型配合物通过一个主要的X****Y硫属元素键(ChB)和次要的C-H****O氢键来稳定。所研究的配合物的结合能在-21.6〜-60.4kJ/mol范围内。Y距离明显小于相应两个原子的范德华半径之和。除SO2‧CH3OCH3复合物外,所有研究复合物中的X‧YChB强度很强,并通过进行分子中原子的量子理论(QTAIM)揭示了部分共价特征,非共价相互作用图(NCIplot),和自然键轨道(NBO)分析。对称适应的扰动理论(SAPT)分析揭示了X*YChB主要由静电成分主导。
In recent years, the non-covalent interactions between chalcogen centers have aroused substantial research interest because of their potential applications in organocatalysis, materials science, drug design, biological systems, crystal engineering, and molecular recognition. However, studies on π-hole-type chalcogen∙∙∙chalcogen interactions are scarcely reported in the literature. Herein, the π-hole-type intermolecular chalcogen∙∙∙chalcogen interactions in the model complexes formed between XO2 (X = S, Se, Te) and CH3YCH3 (Y = O, S, Se, Te) were systematically studied by using quantum chemical computations. The model complexes are stabilized via one primary X∙∙∙Y chalcogen bond (ChB) and the secondary C-H∙∙∙O hydrogen bonds. The binding energies of the studied complexes are in the range of -21.6~-60.4 kJ/mol. The X∙∙∙Y distances are significantly smaller than the sum of the van der Waals radii of the corresponding two atoms. The X∙∙∙Y ChBs in all the studied complexes except for the SO2∙∙∙CH3OCH3 complex are strong in strength and display a partial covalent character revealed by conducting the quantum theory of atoms in molecules (QTAIM), a non-covalent interaction plot (NCIplot), and natural bond orbital (NBO) analyses. The symmetry-adapted perturbation theory (SAPT) analysis discloses that the X∙∙∙Y ChBs are primarily dominated by the electrostatic component.