Heavy pnicogen atoms as electron donors in sigma-hole bonds

DFT calculations evaluate the strength of & sigma;-hole bonds formed by ZH3 and ZMe3 (Z = N, P, As, Sb) acting as electron donor. Bond types considered include H-bond, halogen, chalcogen, pnicogen, and tetrel bond to perfluorinated Lewis acids FH, FBr, F2Se F3As, F4Ge, respectively, as well as their monofluorinated analogues. All of the Z atoms can engage in bonds of at least moderate strength, varying from 3 to more than 40 kcal mol-1. In most cases, N forms the strongest bonds, but the falloff from P to Sb is quite mild. However, this pattern is not characteristic of all cases, as for example in the halogen bonds, where the heavier Z atoms are comparable to, or even stronger than N. Most of the bonds are strengthened by replacing the three H atoms of ZH3 by methyl groups, better simulating the situation that would be generally encountered. Structural and NMR shielding data ought to facilitate the identification of these bonds within crystals or in solution. DFT calculations evaluate the strength of & sigma;-hole bonds formed by ZH3 and ZMe3 (Z = N, P, As, Sb) acting as electron donor.

Automated summary

DFT calculations were conducted to evaluate the strength of σ-hole bonds formed by ZH3 and ZMe3 (Z = N, P, As, Sb) as electron donors. Different bond types were considered, including H-bond, halogen bond, chalcogen bond, pnicogen bond, and tetrel bond, with various Lewis acids as acceptors. The results showed that all Z atoms can form moderately strong bonds, with nitrogen usually forming the strongest bonds.