News tagged with hydrogen bonds

A hydrogen bond is the attractive interaction of a hydrogen atom with an electronegative atom, like nitrogen, oxygen or fluorine (thus the name "hydrogen bond", which must not be confused with a covalent bond to hydrogen). The hydrogen is covalently bonded to another electronegative atom. The energy of a hydrogen bond (typically 5 to 30 kJ/mole) is comparable to that of weak covalent bonds (155 kJ/mol), and a typical covalent bond is only 20 times stronger than an intermolecular hydrogen bond. These bonds can occur between molecules (intermolecularly), or within different parts of a single molecule (intramolecularly). The hydrogen bond is stronger than a van der Waals interaction, but weaker than covalent, or ionic bonds. This type of bond occurs in both inorganic molecules such as water and organic molecules such as DNA.

Intermolecular hydrogen bonding is responsible for the high boiling point of water (100 °C). This is because of the strong hydrogen bond, as opposed to other group 16 hydrides. Intramolecular hydrogen bonding is partly responsible for the secondary, tertiary, and quaternary structures of proteins and nucleic acids.