Synthesis of Functionalized Heteroleptic Germylene Alkoxides

Abstract

N-coordinated Ge(II) alkoxides L 1 (tBuO)Ge (1), L 2 (tBuO)Ge ( 2) and [L 2 (OtBu)Ge • BH 3 ] (4) were prepared. Effect of either chelating ligands L 1 and L 2 or Ge!B interaction on strength of the GeÀ 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 1,2 (2-BrÀ C 6 H 4 O)Ge (5 for L 1 , 8 for L 2 ), L 1,2 (2-MeNHÀ C 6 H 4 O)Ge (6 for L 1 , 9 for L 2 ), L 1,2 (2-Ph 2 PÀ C 6 H 4 O)Ge (7 for L 1 , 10 for L 2 ), L 2 (2-Br-3-OHÀ C 6 H 3 O)Ge ( 11) and L 2 (2-NC 5 H 4 O)Ge (12) containing the additional polar groups Y (Y = Br, MeNH, PPh 2 , 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 BH 3 . As a consequence, new complexes [(k 2 -7)W(CO) 4 ] (13) and [L 1 (2-Ph 2 P • {BH 3 }-C 6 H 4 O)Ge • {BH 3 }] (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.