Triel bonds in RZH2···NH3: hybridization, solvation, and substitution

Zhefeng Xu; Yan Li

doi:10.1007/s00894-019-4089-1

Triel bonds in RZH₂···NH₃: hybridization, solvation, and substitution

J Mol Model. 2019 Jul 12;25(8):219. doi: 10.1007/s00894-019-4089-1.

Authors

Zhefeng Xu¹, Yan Li²

Affiliations

¹ Department of Chemical Engineering, Inner Mongolia Vocational College of Chemical Engineering, Hohhot, 010070, People's Republic of China.
² Department of Chemical Engineering, Inner Mongolia Vocational College of Chemical Engineering, Hohhot, 010070, People's Republic of China. yanli_sub@163.com.

PMID: 31300929
DOI: 10.1007/s00894-019-4089-1

Abstract

The influence of hybridization, substitution, and solvation on the triel bond has been investigated in the complexes of RZH₂···NH₃ (Z = B and Al). The magnitude of the π-hole on the triel atom is related to the nature of the Z atom and the hybridization of R. CH₃BH₂ has the largest π-hole among RBH₂, while for RAlH₂ the largest π-hole is found in CH≡CAlH₂. The interaction energy is partly inconsistent with the magnitude of the π-hole on the triel atom and the orbital interaction from the N lone pair of NH₃ into the empty p orbital of the triel atom. The strongest B···N triel bond is found in CH≡CBH₂···NH₃, while the weakest Al···N triel bond is in CH₃AlH₂···NH₃. The strength of the triel bond is increased in solvents, and its enhancement is prominent with the increase of solvent polarity. Solvents also change the nature of the Al···N triel bond from an electrostatic interaction to a partially covalent one. The F substituent in the triel donor strengthens the triel bond, depending on the substitution position and number. Graphical Abstract The π-hole triel bonded complexes between RZH2 (Z =B and Al) and NH3 have been investigated. We focused on the effects of hybridization, solvent, and substitution on the strength and nature of π-hole triel bond.

Keywords: Hybridization; Solvents; Substituents; Triel bonding.