hydrogen bond donor

A hydrogen bond donor is a molecule or part of a molecule that provides a hydrogen atom for a hydrogen bond to form. Typically, this hydrogen is attached to an electronegative atom like oxygen or nitrogen, making it slightly positive. This positive hydrogen is attracted to a nearby electronegative atom with lone pairs of electrons, called a hydrogen bond acceptor. The donor's role is to supply the hydrogen that participates in these non-covalent, yet strong, interactions, which are important in determining the structure and properties of many biological and chemical systems.