Stable Germylenes Derived from 1,2-Bis(arylimino)acenaphthenes

Metal exchange reactions of the magnesium complexes (dpp-BIAN)Mg(THF)_n, (dtb-BIAN)Mg(THF)_n, and (bph-BIAN)Mg(THF)_n with GeCl₂(dioxane) afford the stable germylenes (dpp-BIAN)Ge (1), (dtb-BIAN)Ge(Et₂O) (2), and (bph-BIAN)Ge (3), respectively (dpp-BIAN = 1,2-[(2,6-iPr₂C₆H₃)N]₂C₁₂H₆, dtb-BIAN = 1,2-[(2,5-tBu₂C₆H₃)N]₂C₁₂H₆, bph-BIAN = 1,2-[(2-PhC₆H₄)N]₂C₁₂H₆). Compound 1 is also obtained from (dpp-BIAN)Na₄ and GeCl₄ in Et₂O. The germylenes 1−3 were characterized by elemental analyses, ¹H NMR, ¹³C NMR, and IR spectroscopy, and X-ray crystal structure analyses. In the monomeric molecules the two imino nitrogen atoms coordinate the germanium atom. The aryl(N) groups are arranged rather orthogonal to the acenaphthenediimine plane. Compound 3 shows an anti geometry with the ortho phenyl substituents of both N-phenyl rings positioned on opposite sides of the acenaphthenediimine plane. The bite angles N−Ge−N are 85.2° (1) and 85.0° (3), respectively. The Ge−N bond distances in 1−3 range from 1.878 to 1.915 Å.