Enhancing chalcogen bonding by metal coordination.

This manuscript shows that chalcogen bonding (ChB) interactions are enhanced by the coordination of the chalcogen atom to metal centers as evidenced using DFT calculations (PBE0-D3/def2-TZVP level of theory). X-ray structures retrieved from the Cambridge Structural Database (CSD) are used to support the enhanced ability of Se and Te-atoms coordinated to transition metals to participate in ChBs, eliminating the necessity to use strong electron-withdrawing groups bonded to the Ch atom. Orbital analysis performed using the natural bond orbital (NBO) technique discloses a large LP → σ* contribution, especially for anionic electron donors. In one example, the new σ-hole that is generated upon complexation (opposite to the Ch-M bond) plays a crucial role in the solid state, promoting the formation of infinite 1D polymers.