The geometries and energetics of noncovalent interactions in chemistry and biology involving aromatic rings – such as pi-pi stacking and edge-to-face contacts, cation-pi,arene-perfluoroarene, and sulfur-arene interactions, as well as H-bonding to pi surfaces – are analyzed taking into account the results from molecular recognition studies with artificial receptors, biostructural work, crystallographic database mining, gas-phase studies, and theoretical calculations. Shown here is a portion of the structure of the
chalcone