The International Union of Pure & Applied Chemistry, IUPAC, has issued chemists with an ultimatum: it intends to break all fleeting, electrostatic hydrogen bonds and remake them as something more akin to covalent bonds. Chemists have until the end of March 2011 to offer their opinions on the new definition of the hydrogen bond. Emerging evidence about the nature of hydrogen bonds suggests that this important phenomenon is underpinned by a degree of electron sharing that the current definition does not accommodate. The new definition will also extend the focus beyond electronegative atoms allowing it to encompass a much wider range of intermolecular and intramolecular connections.
Breaking and remaking hydrogen bonds