Sigma hole interactions

Sigma hole interactions refer to a type of non-covalent interaction that occurs between molecules or molecular fragments in which a region of positive electrostatic potential interacts with a region of negative electrostatic potential. Specifically, the term "sigma hole" is used to describe an area of relative positive charge that appears near the end of a covalent bond, typically associated with a more electropositive atom (like carbon) that is bonded to more electronegative atoms (like fluorine, oxygen, or nitrogen).