On the Potentiality of X-T-X₃ Compounds (T = C, Si, and Ge, and X = F, Cl, and Br) as Tetrel- and Halogen-Bond Donors

Abstract

The versatility of the X-T-X3 compounds (where T = C, Si, and Ge, and X = F, Cl, and Br) to participate in tetrel- and halogen-bonding interactions was settled out, at the MP2/aug-cc-pVTZ level of theory, within a series of configurations for (X-T-X3)2 homodimers. The electrostatic potential computations ensured the remarkable ability of the investigated X-T-X3 monomers to participate in σ-hole halogen and tetrel interactions. The energetic findings significantly unveil the favorability of the tetrel···tetrel directional configuration with considerable negative binding energies over tetrel···halogen, type III halogen···halogen, and type II halogen···halogen analogs. Quantum theory of atoms in molecules and noncovalent interaction analyses were accomplished to disclose the nature of the tetrel- and halogen-bonding interactions within designed configurations, giving good correlations between the total electron densities and binding energies. Further insight into the binding energy physical meanings was invoked through using symmetry-adapted perturbation theory-based energy decomposition analysis, featuring the dispersion term as the most prominent force beyond the examined interactions. The theoretical results were supported by versatile crystal structures which were characterized by the same type of interactions. Presumably, the obtained findings would be considered as a solid underpinning for future supramolecular chemistry, materials science, and crystal engineering studies, as well as a fundamental linchpin for a better understanding of the biological activities of chemicals.

Type I–IV Halogen⋯Halogen Interactions: A Comparative Theoretical Study in Halobenzene⋯Halobenzene Homodimers

“…From the synchronic perspective to the MP2 energetic features, the size of the green-coded regions and the shifting magnitude of the spikes towards the negative sign (λ 2 ) ρ were disclosed to be in line with the binding energy results registered in Table 2 . Overall, the results of the QTAIM and NCI index analyses support previous studies that illustrated the interactions within the type II and III halogen⋯halogen complexes [ 43 , 58 ].…”

“…Apparently, binding energies of type II interactions were spotted to drastically increase with the growth in the atomic size of the interacting halogen atoms, which was previously reported and confirmed by the obtained values [ 58 ]. Numerically, E binding was estimated with values of –1.32, –1.80, and –2.20 kcal/mol for C 6 H 5 Cl⋯ClC 6 H 5 , C 6 H 5 Br⋯BrC 6 H 5 , and C 6 H 5 I⋯IC 6 H 5 homodimers, respectively.…”

“…In that spirit, the MEP maps were generated, and the maximum positive electrostatic potential ( V s,max ) values were computed with the help of Multiwfn 3.7 software [ 66 ]. Using the point-of-charge (PoC) approach, the propensity of the studied monomers to engage in type I-V halogen⋯halogen interactions from the electrostatic perspective was preciously appreciated [ 58 , 67 , 68 , 69 ]. In the PoC approach, negatively- and positively charged points with a value of ±0.50 au were employed to simulate the interactions of halobenzene with a Lewis base and acid, respectively.…”

σ-Hole and LP-Hole Interactions of Pnicogen···Pnicogen Homodimers under the External Electric Field Effect: A Quantum Mechanical Study

“…From the data registered in Table 3 , it can be seen that the studied interactions within all the inspected (PCl 3 ) 2 homodimers were dominated by the dispersion energy ( E disp ), which were earlier reported in the case of halogen, chalcogen, and tetrel homodimers. 62 , 65 , 100 Besides, obvious contributions for the electrostatic ( E elst ) and induction ( E ind ) interactions were also recognized in the designed pnicogen σ-hole and lp-hole interactions. However, exchange energy ( E exch ) demonstrated positive values for all homodimers, outlining unfavorable exchange contributions to the strength of the explored interactions ( Figure 6 ).…”

“…The interactions involving the covalently bonded halogen atoms represent the most well-known type of like···like interactions. 54 − 60 Parallel to halogen···halogen interactions, the interactions of chalcogens, 61 , 62 tetrels, 63 − 65 and triels 66 within like···like configurations were thoroughly addressed. However, a great deal of interest has been directed toward the investigation of pnicogen bonds; there is a paucity in the literature pertinent to the pnicogen···pnicogen interactions.…”