title: Cation⊗3π: cooperative interaction of a cation and three benzenes with an anomalous order in binding energy.
abstract: Cation-π or cation-π-π interaction between one cation and one or two structures bearing rich π-electrons (such as benzene, aromatic rings, graphene, and carbon nanotubes) plays a ubiquitous role in various areas. Here, we analyzed a new type interaction, cation⊗3π, whereby one cation simultaneously binds with three separate π-electron-rich structures. Surprisingly, we found an anomalous increase in the order of the one-benzene binding strength of the cation⊗3π interaction, with K(+) > Na(+) > Li(+). This was at odds with the conventional ranking of the binding strength which usually increases as the radii of the cations decrease. The key to the present unexpected observations was the cooperative interaction of the cation with the three benzenes and also between the three benzenes, in which a steric-exclusion effect between the three benzenes played an important role. Moreover, the binding energy of cation⊗3π was comparable to cation⊗2π for K(+) and Na(+), showing the particular importance of cation⊗3π interaction in biological systems.
authors: School of Physics Science and Technology, Sichuan University, Chengdu 610064, P.R. China.
authors: Manyi
authors: M
authors: Duan
authors: Bo
authors: B
authors: Song
authors: Guosheng
authors: G
authors: Shi
authors: Haikuo
authors: H
authors: Li
authors: Guangfu
authors: G
authors: Ji
authors: Jun
authors: J
authors: Hu
authors: Xiangrong
authors: X
authors: Chen
authors: Haiping
authors: H
authors: Fang
mesh_terms: D001554:Benzene / Q000737:chemistry*; D002412:Cations / Q000737:chemistry*; D004583:Electrons; D008094:Lithium / Q000737:chemistry; D008958:Models, Molecular; D011188:Potassium / Q000737:chemistry; D012964:Sodium / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D002412:Cations; D008094:Lithium; D012964:Sodium; D001554:Benzene; D011188:Potassium