Strong σ-Hole Activation on Icosahedral Carborane Derivatives for a Directional Halide Recognition

Crystal engineering based on sigma-hole interactions is an emerging approach for realization of new materials with higher complexity. Neutral inorganic clusters derived from 1,2-dicarba-closo-dodecaborane, substituted with -SeMe, -TeMe, and -I moieties on both skeletal carbon vertices are experimentally demonstrated herein as outstanding chalcogen- and halogen-bond donors. In particular, these new molecules strongly interact with halide anions in the solid-state. The halide ions are coordinated by one or two donor groups (mu(1)- and mu(2)-coordinations), to stabilize a discrete monomer or dimer motifs to 1D supramolecular zig-zag chains. Crucially, the observed chalcogen bond and halogen bond interactions feature remarkably short distances and high directionality. Electrostatic potential calculations further demonstrate the efficiency of the carborane derivatives, with V-s,V-max being similar or even superior to that of reference organic halogen-bond donors, such as iodopentafluorobenzene.

Automated summary

Crystal engineering based on sigma-hole interactions is a promising approach for creating new materials with higher complexity. The study demonstrates that carborane derivatives can strongly interact with halide anions, forming highly ordered molecular chains with remarkably short distances and high directionality. Additionally, electrostatic potential calculations show that these derivatives have similar or even superior efficacy compared to organic halogen-bond donors.