H3XF (X = Ge, Si)与芳香环化合物间硅键作用的理论研究

Theoretical Study of Tetrel-Bonding Interactions between H3XF (X = Ge, Si) and Aromatic Ring Compounds

通过量子化学计算方法MP2对H3XF (X = Ge, Si)和五种芳香环化合物(苯、吡啶、吡咯、呋喃、噻吩)形成的硅键复合物进行了研究。复合物的结合模式可分为两类,模式I复合物中X主要与芳香环碳原子发生硅键相互作用,模式II则主要与芳香环杂原子发生硅键相互作用。H3XF与所有芳香环化合物都能形成模式I复合物,稳定性顺序为:吡咯 >噻吩 >苯 >呋喃 >吡啶。H3XF则只能与三种芳香环化合物形成模式II复合物,稳定性顺序为:吡啶 >噻吩 >呋喃。分析表明模式I复合物均为π型硅键,而模式II复合物则各不同:吡啶模式II复合物为n型硅键,呋喃模式II复合物为n/π型硅键,噻吩模式II复合物为π型硅键。

The tetrel-bonding complexes formed between H3XF(X=Ge,Si)and the selected aromatic ring compounds(benzene,pyridine,pyrrole,furan and thiophene)have been investigated by MP2 quantum chemical method.There exist two binding modes for these complexes.The X atoms mainly interact with the carbon atoms of aromatic ring compounds for mode I complexes,while the X atoms mainly interact with the hetero atoms for binding mode II complexes.All the aromatic ring compounds can form mode I complexes with H3XF,and the order of stability is pyrrole>thiophene>benzene>furan>pyridine.Only three aromatic ring compounds can form mode II complexes with H3XF,and the order of stability is pyridine>thiophene>furan.All the five mode I complexes areπ-type tetrel-bonding complexes,but the mode II complexes are different from each other:the mode II complex of pyridine is n-type complex;the mode II complex of furan is n/π-type complex;and the mode II complex of thiophene isπ-type complex.