Pnictogen bond

In chemistry, a pnictogen bond (PnB) is a non-covalent interaction, occurring where there is a net attractive force between an electrophilic region on a 'donor' pnictogen atom (Pn) in a molecule, and a nucleophilic region on an 'acceptor' atom, which may be in the same or another molecule.

[3] In such cases, polarisation of the pnictogen atom by an electron-withdrawing substituent, results in an anisotropic electron distribution in the Pn atom affording a directional electropositive region, resulting in an attractive electrostatic interaction.

PnB donors have been demonstrated to be capable of functioning as Lewis acidic catalysts.

[7] Given their intermediate position in the main group of the periodic table, PnB catalysis may be appealing due to a balance between steric repulsion and polarisability factors.

As for halogen and chalocogen bonding interactions, the σ-hole interactions in PnB hosts have been exploited for anion binding and recognition, with a report in 2022 exploiting a series of triaryl antinomy and bismuth receptors for binding of halide anions.

Orbital mixing schematic for an n → σ* interaction which result in a charge transfer contribution to pnictogen bonds.
A triaryl bismuth(III) complex capable of binding anions through pnictogen bonding interactions
A pnictogen bonding anion receptor from Beer and co-workers.