Identification of the Tetrel Bonds between Halide Anions and Carbon Atom of Methyl Groups Using Electronic Criterion.

Ekaterina Bartashevich,Yury Matveychuk,Vladimir Tsirelson

doi:10.3390/molecules24061083

Ekaterina Bartashevich, Yury Matveychuk + Show 1 more

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https://doi.org/10.3390/molecules24061083

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Abstract

The consideration of the disposition of minima of electron density and electrostatic potential along the line between non-covalently bound atoms in systems with Hal−···CH3–Y (Hal− = Cl, Br; Y = N, O) fragments allowed to prove that the carbon atom in methyl group serves as an electrophilic site provider. These interactions between halide anion and carbon in methyl group can be categorized as the typical tetrel bonds. Statistics of geometrical parameters for such tetrel bonds in CSD is analyzed. It is established that the binding energy in molecular complexes with tetrel bonds correlate with the potential acting on an electron in molecule (PAEM). The PAEM barriers for tetrel bonds show a similar behavior for both sets of complexes with Br− and Cl− electron donors.

Highlights

The problem of categorizing non-covalent interactions in molecular crystals and complexes is a focus of attention [1,2]
The typical tetrel bonds formed by CH3 -group in crystals have been been observed by high-precision X-ray diffraction method using the analysis of the experimental electron density [17,18]
The aim of the present study is to demonstrate the efficiency and productivity of the above-mentioned electronic criterion and the potential acting on an electron in molecule (PAEM) for analysis of tetrel bonds between the carbon atom of methyl groups and halide anions, which sometimes occur in molecular crystals

Summary

Introduction

The problem of categorizing non-covalent interactions in molecular crystals and complexes is a focus of attention [1,2]. The systematization of the halogen, chalcogen, pnictogen, and tetrel bonds already exists [3]; in most cases, only the simplistic geometrical approach underlies the analysis of such types of interactions. The carbon atom in the CH3 -group is fairly often noted as the owner of σ-hole, and the fact that the oxygen atom can act as an electron-rich center in the CH3 ···O tetrel bonding has been confirmed in studies [14,15]. Note that in these early works such non-covalent interaction has been referred as a “carbon bond”. The typical tetrel bonds formed by CH3 -group in crystals have been been observed by high-precision X-ray diffraction method using the analysis of the experimental electron density [17,18]

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