钙离子与二嗪相互作用的理论研究

Theoretical Study on the Interaction of Calcium Cation and Diazine

用密度泛函理论和多体微扰理论,对钙离子与二嗪形成的复合物Can+-C4H4N2(n=1,2)的平衡几何构型和稳定性进行了研究.计算结果表明,Ca2+与对二嗪可形成稳定的π配合物,Ca2+和Ca+与邻二嗪和对二嗪均可形成稳定的σ配合物.对优化得到的稳定配合物计算了钙离子与二嗪的结合能和相互作用势.用NBO和AIM分析法,讨论了钙离子-σ和钙离子-π相互作用的本质.

Both the geometries and stabilities, by means of the density functional theory and MP2 calculation, have been obtained for a series of calcium cation-diazine complexes Ca^n＋-diazine （n=1, 2） with restricted and unrestricted optimization. The current study demonstrates that Ca^2＋-pyrazine have stable π complexes, while Can^n＋-diazine （n=1, 2） systems prefer the σ complexes to the π- ones. Binding energy and interaction potential of calcium cation and diazine ring are based on the calculation of all the complexes of optimized structures. The nature of calcium cation-σ interaction and that of its π interaction have been discussed by NBO and AIM analysis.