Sc3C2@C80与[12]CPP纳米环之间非共价相互作用的理论研究

金属富勒烯嵌套于纳米环内形成主客体系, 二者产生的主客体作用可诱导内部金属团簇的取向, 影响分子的电子结构等性质. 本文基于密度泛函理论(DFT)计算, 对碳纳米环12]CPP(CPP=环苯撑, 主体分子)与金属富勒烯Sc₃C₂@C₈₀(客体分子)形成的主客体配合物的结构和性质进行了研究. 计算结果表明, 在最稳定构型中, 12]CPP呈现椭圆形, Sc₃C₂@C₈₀与12]CPP的质心不再重合. Sc₃C₂@C₈₀在12]CPP内旋转对构型总体能量影响仅为13.51 kJ/mol. 12]CPP向Sc₃C₂@C₈₀转移了0.03 e, 主客体分子之间存在弱相互作用. 对二者相互作用的分析结果表明, 色散作用在弱相互作用中占主导地位.

Theoretical Exploration of Noncovalent Interactions Between Sc3C2@C80 and ［12］Cycloparaphenylene Nanoring

The encapsulations of fullerenes by carbon-nanorings are of great interest because of their unique molecular structure and special properties. The host-guest interaction between them can induce the orientation of metal ions and change the molecular electronic structure. However， due to experimental di?culties， there are many opportunities for the computational efforts to deeply research the intrinsic features of π-π noncovalent interactions of the fullerene?cycloparaphenylene（CPP） carbon-nanoring host-guest systems. Herein， the molecular carbon nanoring of ［12］cycloparaphenylene was used to hoop the C₈₀-based metallofullerene Sc₃C₂@C₈₀. The structures and properties of the host-guest complex were systematically characterized by density functional theory（DFT） calculations. It was found that ［12］CPP is deformed because of the asymmetrical attraction of ［12］CPP to Sc₃C₂@C₈₀. The centroids of Sc₃C₂@C₈₀ and ［12］CPP no longer coincide. The results also showed that the influence of rotation of Sc₃C₂@C₈₀ in ［12］CPP on the overall energy of the configuration is only 13.51 kJ/mol. Moreover， charge population analysis shows that 0.03 electrons are transferred from ［12］CPP to Sc₃C₂@C₈₀ during the formation of Sc₃C₂@C₈₀?［12］CPP. Weak interactions between host-guest systems can be further partitioned with the help of energy decomposition analysis（EDA）. EDA analysis shows that dispersion is dominant. These results provide theoretical support for the study of host-guest systems based on metallofullerenes.