The Role of π Electrons in the Formation of Benzene-Containing Lithium-Bonded Complexes

Authors

  • Prof. Yanli Zeng,

    1. Institute of Computational Quantum Chemistry, College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050016 (P.R. China)
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  • Min Zhu,

    1. Institute of Computational Quantum Chemistry, College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050016 (P.R. China)
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  • Prof. Lingpeng Meng,

    1. Institute of Computational Quantum Chemistry, College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050016 (P.R. China)
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  • Prof. Shijun Zheng

    Corresponding author
    1. Institute of Computational Quantum Chemistry, College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050016 (P.R. China)
    • Institute of Computational Quantum Chemistry, College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050016 (P.R. China)
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Abstract

The intermolecular interactions in C6H6⋅⋅⋅LiX (X=OH, NH2, F, Cl, Br, NC, CN) complexes are investigated by using second-order Møller–Plesset perturbation theory (MP2) calculations and quantum theory of “atoms in molecules” (QTAIM) studies, and the role of π electrons is studied in the formation of these benzene-containing lithium-bonded complexes. The molecular electrostatic potentials of benzene and LiX determine the geometries of the lithium-bonded complexes. The electron densities at the lithium bond critical points in the πC6H6⋅⋅⋅LiX complexes are obviously stronger than those in the σC6H6⋅⋅⋅LiX complexes, which indicates that the intermolecular interactions in the C6H6⋅⋅⋅LiX complexes are mainly attributable to π-type interaction. The topological and energy properties at the lithium bond critical points in both the C6H6⋅⋅⋅LiX and πC6H6⋅⋅⋅LiX complexes are linear with the interaction energies, thereby showing the crucial role of the π electrons in the formation of these complexes. Electron localization function (ELF) analysis indicates that the formation of the lithium bonds leads to the reduction of the ELF π-electron density and volume, and the reduction of the π-electron volume is linear with the interaction energies with the correction coefficient 0.9949.

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