【摘要】 采用B3LYP/6-311++G(d,p),B3LYP/aug-cc-pVDZ,MP2/6-311++G(d,p),MP2/aug-cc-pVDZ,MP2/aug-cc-pVTZ5种方法,对氧硫化碳(OCS)分子中的硫原子与系列烯、炔烃之间形成的T型复合物进行了理论研究,侧重从电子密度拓扑分析的角度,对OCS与系列烯、炔烃之间形成S…π作用进行研究.通过σ-π分离,首次获得烯、炔烃的π电子密度分布函数,从而能够直观、定量地讨论这类π型作用的成键特性.研究结果表明:随着电子给体中碳原子数的增多,复合物相互作用能逐渐增大,复合物中S-C键、C-O键红移越多.OCS与烯、炔烃之间的S…π相互作用,属于闭壳层相互作用,以静电作用为主,且随着电子给体中碳原子数的增加,静电作用增强.S…π键键鞍点的电子密度拓扑参数(ρ(b),▽2ρ(b),Gb,Vb)与复合物相互作用能有很好的线性关系.更多还原

【Abstract】 The T-shaped complexes OCS…hydrocarbon were investigated at the B3LYP/6-311++G(d,p),B3LYP/aug-cc-pVDZ,MP2/6-311++ G(d,p),MP2/aug-cc-pVDZ,and MP2/aug-cc-pVTZ levels of theory.The S…π bonding interaction was studied by topological analysis of electron density.We separated the σ and π electron densities and obtained the π electron density function.We described the bonding character of this π-type interaction visually and quantitatively.The result shows that the binding energy of the T-shaped complexes increases with the number of carbon atoms in the electron donors,as does the extent of the redshift of S-C and C-O bonds.The S…π interactions between OCS and hydrocarbon belong to noncovalent "closed-shell" electrostatic interactions.The electrostatic interaction also increases with the number carbon atoms in the electron donors.The topological parameters are linearly related to the interaction energies.更多还原