Computational insight into pnictogen bonds in the self-assembly of caged pnictogen compounds

Abstract In current years, specific rigid caged structures have been designed to facilitate self-assembly via multiple pnictogen bonds (PnBs). On the basis of our survey of the Cambridge Structure Database and recent crystallographic reports, two sets of dimeric complexes of pnictogen alkoxide cages 1-Pn and pnictogen pyrrole crowns 2-Pn were selected to model PnB interactions in the self-assembly of caged pnictogen compounds. Electrostatic interactions play an important role in the formation of these complexes. The introduction of different substituents into the skeleton 1-Pn affects the properties of double Pn⋯O interactions slightly, because of the opposite influence of these substituents on the donor and acceptor abilities. However, the Pn⋯N interaction strength enhances to a large degree with the presence of strong electron-withdrawing substituents into 2-Pn, due to the markedly increased donor ability of pnictogens.