Synthesis of Functionalized Heteroleptic Germylene Alkoxides

N-coordinated Ge(II) alkoxides L-1(tBuO)Ge (1), L-2(tBuO)Ge (2) and [L-2(OtBu)Ge center dot BH3] (4) were prepared. Effect of either chelating ligands L-1 and L-2 or Ge -> B interaction on strength of the Ge OtBu bond was studied by insertion reaction of PhNCO. As a result, the Ge(II) carbamate L-2{[(tBuO)OC](Ph)N}Ge (3) was isolated. Alcoholysis exchange reactions of 1 and 2 with substituted phenols were studied to find an easy synthetic protocol for a synthesis of functionalized Ge(II) alkoxides. Reactions yielded Ge(II) alkoxides L-1,L-2(2-Br-C6H4O)Ge (5 for L-1, 8 for L-2), L-1,(2)(2-MeNH C6H4O)Ge (6 for L-1, 9 for L-2), L-1,L-2(2- Phy(2)P-C6H4O)Ge (7 for L-1, 10 for L-2), L-2(2-Br-3-OH-C6H3O)Ge (11) and L-2(2-NC5H4O)Ge (12) containing the additional polar groups Y (Y- Br, MeNH, PPh2, OH or N). Finally, phosphane decorated Ge(II) alkoxides 7 and 10 were tested as suitable ligands in reactions with (COD)W(CO)(4) and BH3. As a consequence, new complexes [(kappa(2)-7)W(CO)(4)] (13) and [L-1(2-Ph2P center dot{BH3}-C6H4O)Ge center dot{BH3}] (14) were isolated. All compounds were characterized by NMR and IR spectroscopy, and compounds 3, 4, 9 and 11 were additionally characterized by X-ray diffraction analysis.