Term: hydrogen bond
https://doi.org/10.1351/goldbook.HT07050

Definition:
A particular type of multicenter (three center - four electron) X–H ...Y in which the central hydrogen atom covalently linked to an electronegative atom X (C, N, O, S...) forms an additional weaker bond with atom Y (N, O, S...) in the direction of its lone electron pair orbital. The energy of hydrogen bonds, which is usually in the range of 3-15 kcal/mol (12-65 kJ/mol), results from the electrostatic interaction and also from the orbital interaction of the antibonding σ*(XH)MO of the molecule acting as the hydrogen donor and the non-bonding lone electron pair MOnY of the hydrogen acceptor molecule.

Source: PAC, 1999, 71, 1919. 'Glossary of terms used in theoretical organic chemistry' on page 1945 (https://doi.org/10.1351/pac199971101919)

Citation: 'hydrogen bond' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.HT07050

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