Soft (S₃-Donor) Scorpionate Complexes of Molybdenum and Tungsten Carbonyls

The dicarbonyl(η³-allyl)molybdenum and tricarbonyliodotungsten complexes with hydrotris(methimazolyl)borate (Tm) are reported as the first examples of transition-metal organometallic complexes of the Tm ligand, serving as general entry points for a wide range of group 6 organometallic complexes. Their crystal structures have been determined, and comparisons are made with the homologous pyrazolylborate (Tp) and cyclopentadienyl (Cp) complexes, leading to predictions regarding their reactions.