Hbonds
Hbonds are non-covalent interactions that form between a hydrogen atom covalently bonded to an electronegative donor atom (such as oxygen, nitrogen, or fluorine) and an electronegative acceptor atom bearing a lone pair. The hydrogen acts as a bridge between the donor and acceptor, resulting in an interaction that is stronger than most van der Waals contacts but weaker than covalent bonds. Geometrically, Hbonds are most favorable when the X–H...Y angle is near linear and the X–H...Y distance falls in about 2.7 to 3.2 Å for typical O–H...O or N–H...N arrangements.
Energetics vary with environment but generally yield bond energies of roughly 4 to 40 kJ per mole.
Hbonds play a central role in the structure and function of many systems. In water, they create
Because Hbonds are sensitive to distance, angle, and the surrounding solvent, they are inherently dynamic. They