Can Remote N-Heterocyclic Carbenes Coordinate with Main Group Elements? Synthesis, Structure, and Quantum Chemical Analysis of N+ -Centered Complexes.

Remote N-heterocyclic carbenes (rNHCs), such as N-methyl-4-pyridylidene, are known to form coordination complexes with TMs. Herein, it is established that rNHCs can also coordinate to the N+ centre. Synthesis of some novel divalent NI complexes with the general formula (rNHC)→N+ ←(NHC) and (rNHC)→N+ ←(rNHC) was achieved, and X-ray diffraction studies supported the coordination bond character between the rNHCs and the N+ centre. Quantum chemical analysis established the presence of divalent NI character at the central nitrogen in these systems.