Anti-Electrostatic Hydrogen Bonds

Abinitio and hybrid density functional techniques were employed to characterize a surprising new class of H-bonded complexes between ions of like charge. Representative H-bonded complexes of both anion-anion and cation-cation type exhibit appreciable kinetic stability and the characteristic theoretical, structural, and spectroscopic signatures of hydrogen bonding, despite the powerful opposition of Coulomb electrostatic forces. All such anti-electrostatic H-bond (AEHB) species confirm the dominance of resonance-type covalency (charge transfer) interactions over the inessential (secondary or opposing) ionic or dipole-dipole forces that are often presumed to be essential for numerical modeling or conceptual explanation of the H-bonding phenomenon.