What is the main type of intermolecular force present in a hydrogen bond?

Hydrogen bonds are a type of dipole-dipole interaction that occurs specifically when hydrogen is bonded to highly electronegative atoms such as oxygen, nitrogen, or fluorine. In this scenario, the hydrogen atom has a partial positive charge due to the strong electronegativity of the atom it is bonded to, leading to an attraction between this positively charged hydrogen atom and the lone pair of electrons on another electronegative atom nearby.

This characteristic interaction is stronger than regular dipole-dipole interactions because of the significant difference in electronegativity between hydrogen and the electronegative element, resulting in a more pronounced dipole. Therefore, the nature of hydrogen bonding distinctly positions it as a subtype of dipole-dipole interaction rather than an ionic bond or covalent bond, which involve different types of atomic interactions, or London dispersion forces, which arise from temporary fluctuations in electron density in nonpolar molecules.