Lithium Complexes of Neutral Bis-NHC Ligands

The employment of lithium hexamethyldisilazide for the deprotonation of methylene-bridged bis­(imidazolium) salts led to the formation of lithium carbene adducts. Depending on the crystallization method and the substituents of the ligands, monomeric, dimeric, or polymeric solid-state structures were obtained. These lithium carbene complexes represent the first examples of lithium complexes bearing neutral bis­(N-heterocyclic carbene) ligands.