The Cation−π Interaction

Noncovalent interactions play a dominant role in
\nmany forefront areas of modern chemistry, from
\nmaterials design to molecular biology. A detailed
\nunderstanding of the physical origin and scope of
\nsuch interactions has become a major goal of physical
\norganic chemistry. Compared to the more conventional
\ninteractions such as hydrogen bonds, ion pairs
\n(salt bridges), and the hydrophobic interaction, the
\ncation-π interaction has been relatively underappreciated.
\nIt is not a new effect-experimental support
\nfor a prominent interaction in the gas phase
\nappeared more than 15 years ago, and the potential for such an interaction has always been evident from
\nan electrostatic analysis of benzene.