Synthesis and Structure of [M(N-inethyliinidazole)₆]S₈ (M = Mn, Fe, Ni, Mg). Polysulfide Salts Prepared by the Reaction N-Methylimidazole + Metal Powder + Sulfur

Powdered magnesium, manganese, iron, and nickel were found to dissolve in N-methylimidazole (N-MeIm) solutions of elemental sulfur to give red-colored salts [M(N-MeIm)₆]S₈. The structure of the nickel complex was determined by single-crystal X-ray diffraction. The compound crystallizes in the triclinic space group P1 with a = 8.027 (5) Å, b = 10.785 (2) Å, c = 11.531 (2) Å, α = 112.79 (2)°, β = 92.35 (3)°, γ = 96.11 (3)°, Z = 1. The structure analysis revealed a centrosymmetric cation that is analogous to other hexakis(imidazole) complexes. The compounds [M(N-MeIm)₆]S₈ are rare examples of polysulfide salts of transition-metal complexes. The IR spectra of the new compounds were analyzed by comparison with samples of [M(N-MeIm)₆]I₂ that were prepared by the reaction of the metal powders with iodine in N-MeIm solution.