Noncovalent Bonds between Tetrel Atoms |
| |
Authors: | Dr Anna Grabarz Dr Mariusz Michalczyk Dr Wiktor Zierkiewicz Prof Steve Scheiner |
| |
Institution: | 1. Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland;2. Department of Chemistry and Biochemistry, Utah State University Logan, Utah, 84322-0300 United States |
| |
Abstract: | The pairing of TFH3 with a TH2CH3− anion, where T represents tetrel atoms C, Si, Ge, Sn, Pb, results in a strong direct interaction between the two T atoms. The interaction energy is sensitive to the nature of the two T atoms but can be as large as 90 kcal/mol. The noncovalent bond strength rises quickly as the basic T atom of the anion becomes smaller, or as the Lewis acid T grows larger, although there is less sensitivity to the latter atom. The electrostatic component makes up some 55–70 % of the total attraction energy. This term is well accounted for by simple combination of the maximum and minimum values of the molecular electrostatic potential of the Lewis acid and base units, respectively. The complexation induces a rearrangement in the TFH3 molecule from tetrahedral to trigonal pyramidal. The associated deformation energy reduces the exothermicity of the complexation reaction. Electron density shift patterns reveal a density loss on the basic T atom, along with accompanying increases on the acidic T and its attached F atom. |
| |
Keywords: | deformation energy electrostatic potentials energy decomposition noncovalent bonding tetrel bonds |
|
|