An Overview of σ-Hole Bonding, an Important and Widely-Occurring Noncovalent Interaction

摘要: σ-Hole bonding is a highly directional noncovalent interaction between positive region on covalently-bonded Group IV–VII atom and negative site another molecule, e.g., lone pair of Lewis base. The reflects the electron deficiency in outer lobe p-type orbital involved covalent bond along extension this bond. There now considerable experimental computational evidence for σ-hole bonding. Within given group, particular base, strength increases with polarizability electron-withdrawing power remainder molecule. For Groups IV–VI, there can be more than one atom. series molecules, we give computed values surface electrostatic potentials associated σ-holes, also present some calculated energies different bases. competitive hydrogen bonding, but two accompany each other. σ-holes usually exist conjunction regions remainders atoms’ surfaces, so that interactions electrophiles as well nucleophiles are possible. It is, therefore, not valid to assign single global atomic charges these instances. Examples molecular biology crystal engineering discussed.