The Hydrogen Bond in the Solid State

TLDR

Hydrogen bonding is a key directional intermolecular interaction that shapes molecular conformation, aggregation, and function across inorganic and biological systems, and its study has evolved rapidly since the 1990s. This review aims to provide a coherent survey of hydrogen bonding phenomena, including their diverse types and underlying interactions. The authors conduct a comprehensive literature survey, classifying hydrogen bonds by type and analyzing their dissociation energies and relative electrostatic, covalent, and dispersion contributions. Hydrogen bonds exhibit dissociation energies ranging from 0.2 to 40 kcal mol⁻¹, with electrostatic, covalent, and dispersion contributions varying across a continuum that merges into covalent, van der Waals, ionic, and cation–π interactions.

Abstract

The hydrogen bond is the most important of all directional intermolecular interactions. It is operative in determining molecular conformation, molecular aggregation, and the function of a vast number of chemical systems ranging from inorganic to biological. Research into hydrogen bonds experienced a stagnant period in the 1980s, but re-opened around 1990, and has been in rapid development since then. In terms of modern concepts, the hydrogen bond is understood as a very broad phenomenon, and it is accepted that there are open borders to other effects. There are dozens of different types of X−H⋅⋅⋅A hydrogen bonds that occur commonly in the condensed phases, and in addition there are innumerable less common ones. Dissociation energies span more than two orders of magnitude (about 0.2–40 kcal mol−1). Within this range, the nature of the interaction is not constant, but its electrostatic, covalent, and dispersion contributions vary in their relative weights. The hydrogen bond has broad transition regions that merge continuously with the covalent bond, the van der Waals interaction, the ionic interaction, and also the cation–π interaction. All hydrogen bonds can be considered as incipient proton transfer reactions, and for strong hydrogen bonds, this reaction can be in a very advanced state. In this review, a coherent survey is given on all these matters.