Bulky tris(mercaptoimidazolyl)borates: synthesis and molecular structures of the Group 12 metal complexes [TmtBu]MBr (M = Zn, Cd, Hg)

An improved preparation of the bulky tris(mercaptoimidazolyl)borate ligand [TmtBu]− is reported together with convenient high yield syntheses of the Group 12 metal derivatives [TmtBu]MBr (M = Zn, Cd, Hg). The molecular structures of the three new complexes have been determined by single-crystal X-ray diffraction and together constitute the first complete triad of TmR compounds in the periodic table to be structurally characterized. The isostructural complexes display in the solid state distorted tetrahedral structures, with the heavier members of the group exhibiting larger Br–M–S and smaller S–M–S angles.