Group 13 Element Trihalide Complexes of Anionic N-Heterocyclic Carbenes

A series of group 13 complexes of the general type [{(WCA-IDipp)EX₃ }Li(solv)] (E=B, Al, Ga, In; X=Cl, Br) that bear an anionic N-heterocyclic carbene ligand with a weakly coordinating borate moiety (WCA-IDipp, WCA=B(C₆ F₅ )₃ and IDipp=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) were prepared by the reaction of the respective group 13 trihalides (EX₃ ) with the lithium salt [(WCA-IDipp)Li ⋅ toluene]. The molecular structures of the BBr₃ , AlCl₃ , AlBr₃ , GaCl₃ and InCl₃ adducts were established by X-ray diffraction analyses, revealing the formation of coordination polymers linked by halide-lithium interactions, except for the indium derivative, which consists of isolated [Li(THF)₄ ]⁺ and [(WCA-IDipp)InCl₃ ]^- ions in the solid state.