OH Functionality of Germanium(II) Compounds for the Formation of Heterobimetallic Oxides

Two novel germanium(II) μ-oxo heterobimetallic oxides with different oxidation states at the metal centers have been reported. The reaction of LGeOH [L = N(Ar)C(Me)CHC(Me)N(Ar) (Ar = 2,6-i-Pr2C6H3)] with Cp2MMe2 (M = Zr, Hf) in Et2O afforded LGeOM(Me)Cp2 [M = Zr (2), Hf (3)] in moderate yield. Compounds 2 and 3 were characterized by elemental analysis, IR, NMR, EI-MS, and single X-ray structural analysis. Compounds 2 and 3 crystallized in the space group P1̄, and the geometry at the metal centers is tetrahedral. The Ge−O bond lengths of 2 and 3 are very similar (1.797(2) and 1.799(3) Å, respectively), and a bent M−O−M‘ angle in 2 (143.8(1)°) and 3 (141.9(2)°) features both oxide systems. Different orientations of the Cp and Me groups of the metal centers were observed, and deviations of the Cp groups were exhibited.