✍ Scribed by Matthias Driess; Nicoleta Dona; Klaus Merz
No coin nor oath required. For personal study only.
New fascinating electronic features of the simple diketoamine chelate ligand HN[CH~2~C(__t__Bu)O]~2~ (1) are described. Unexpectedly, the corresponding trianionic amido‐dienolate form of 1 is capable of reducing main‐group metal atoms M after initial coordination and intramolecular L→M two‐electron transfer and of stabilizing main‐group elements in unusual low oxidation states. This is impressively shown by the synthesis and structural characterization of the novel Ge and Sn complexes 4–6 by redox reactions of lithiated 1 with the corresponding metal halides GeCl~4~ and MCl~2~ (M=Ge, Sn). Surprisingly, conversion of tris‐lithiated 1 with GeCl~4~ readily consumes two molar equivalents of GeCl~4~ and results in the formation of the neutral GeCl~3~ complex 4 and GeCl~2~. The former represents the second example of a structurally characterized neutral octahedrally coordinated germanium compound. Reaction of dilithiated 1 with GeCl~2~ does not lead to the expected ClGe(+2) complex but affords the novel dimeric germylene 5, whereas similar reaction using SnCl~2~ furnishes the monomeric stannylene (ClSn(+2) complex) 2 and elemental tin due to the higher oxidation potential of Sn(+2). Unexpectedly, a similar redox reaction of dilithiated 1 with PbCl~2~ furnishes the first air‐ and water‐stable lithium 1,2‐diketoimine–enolate 7 and elemental lead. Compound 7 is tetrameric in the solid state and consists of a strongly distorted Li~4~O~4~ cubic core with trigonal‐bipyramidal coordinated Li^+^ ions.
📜 SIMILAR VOLUMES
Bridging ligands / Constrained geometry catalysts / Cyclopentadienyl ligands / Isoelectronic analogues / Isolobal relationship / Phosphoranes / Phosphorus ylides / Indenyl / Sodium IndPPh 2 (1) reacts with RCH 2 Br to form the phosphonium salts [RCH 2 P(Ph) 2 Ind] + Br -(2: R = Ph; 3: R = C 6 F 5 )