Mutual Influence between Halogen Bonds and Cation-π Interactions: A Theoretical Study

• Published in: Chemphyschem 2012-06, Vol.13 (8), p.2154-2161
• Main Authors: Lu , Yunxiang, Liu , Yingtao, Li, Haiying, Zhu, Xiang, Liu, Honglai, Zhu, Weiliang
• Format: Article
• Language: English
• Subjects: Ab initio calculations; Atomic and molecular physics; Calculations and mathematical techniques in atomic and molecular physics (excluding electron correlation calculations); cation-π interactions; Cations - chemistry; cooperative effects; diminutive effects; Electronic structure of atoms, molecules and their ions: theory; Exact sciences and technology; halogen bonds; Halogens - chemistry; Magnesium - chemistry; Models, Theoretical; Physics; Sodium - chemistry
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201200035

The interplay between halogen bonds and cation–π interactions is investigated by ab initio calculations at the MP2 level of theory. Different energetic effects are observed in the studied complexes in which halogen bonds and cation–π interactions coexist, which can be ascribed to the direction of charge transfer for the two interactions. These effects are analyzed in detail in terms of the structural, energetic, and charge‐transfer properties of the complexes. In addition, the quantum theory of atoms in molecules is employed to characterize the interactions and to examine their enhancement and attenuation in terms of the variations in electron density at the bond and cage critical points. Finally, experimental evidence for a combination of the two interactions is obtained from the Cambridge Structural Database. Cooperative or diminutive effects are observed when halogen bonds and cation–π interactions coexist in the same complex, depending on the mutal directions of charge transfer of the two interactions (see picture).