Anion-arene adducts: C-H hydrogen bonding, anion-π interaction, and carbon bonding motifs

This article summarizes experimental and theoretical evidence for the existence of four distinct binding modes for complexes of anions with charge-neutral arenes. These include C-H hydrogen bonding and three motifs involving the arene-π system-the noncovalent anion-π interaction, weakly covalent σ interaction, and strongly covalent σ interaction.