Molecules (Nov 2021)

Hydrogen and Lithium Bonds—Lewis Acid Units Possessing Multi-Center Covalent Bonds

  • Mohammad Aarabi,
  • Samira Gholami,
  • Sławomir J. Grabowski

DOI
https://doi.org/10.3390/molecules26226939
Journal volume & issue
Vol. 26, no. 22
p. 6939

Abstract

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MP2/aug-cc-pVTZ calculations were carried out on complexes wherein the proton or the lithium cation is located between π-electron systems, or between π-electron and σ-electron units. The acetylene or its fluorine and lithium derivatives act as the Lewis base π-electron species similarly to molecular hydrogen, which acts as the electron donor via its σ-electrons. These complexes may be classified as linked by π-H∙∙∙π/σ hydrogen bonds and π-Li∙∙∙π/σ lithium bonds. The properties of these interactions are discussed, and particularly the Lewis acid units are analyzed, because multi-center π-H or π-Li covalent bonds may occur in these systems. Various theoretical approaches were applied here to analyze the above-mentioned interactions—the Quantum Theory of Atoms in Molecules (QTAIM), the Symmetry-Adapted Perturbation Theory (SAPT) and the Non-Covalent Interaction (NCI) method.

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