Sigma hole interactions

Intermolecular forces between oppositely-charged sites on molecules

In chemistry, sigma hole interactions are a family of intermolecular forces that can occur between several classes of molecules and arise from an energetically stabilizing interaction between a positively-charged site, termed a sigma hole, and a negatively-charged site, typically a lone pair, on different atoms that are not covalently bonded to each other. These interactions are usually rationalized primarily via dispersion, electrostatics, and electron delocalization and are characterized by a strong directional preference that allows control over supramolecular chemistry.

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