The potentiality of sp
3
-hybridized chalcogen-containing
molecules to participate in lone-pair (lp) hole interactions was reported
for the first time. lp hole interactions were characterized and compared
to σ-hole ones for OF
2
and SF
2
molecules
as a case study
.
Various quantum mechanical calculations,
including molecular electrostatic potential (MEP), maximum positive
electrostatic potential (
V
s,max
), point
of charge (PoC), symmetry-adapted perturbation theory (SAPT), quantum
theory of atoms in molecule (QTAIM), and reduced density gradient–noncovalent
interaction (RDG-NCI) calculations, were carried out. The more significant
findings to emerge from this study are the following: (i) the
V
s,max
calculation was proved to be an unreliable
method to determine the precise σ-hole and lp hole locations.
(ii) The maximum positive electrostatic potential of the σ hole
and lp hole was found to be at the F–Chal···PoC
angle (θ) of 180° and at the centroid of XYlp plane, respectively.
(iii) Lewis basicity has a significant effect on the strength of σ-hole
and lp hole interactions. (iv) The studied molecules more favorably
interact with Lewis bases via the σ hole compared to the lp
hole, and (v) stabilization of the σ-hole and lp hole interactions
stems from the electrostatic and dispersion forces, respectively.