A μ4‐oxide‐containing a dimeric variant of a sodium dialkyl(amido)zincate reagent

Post‐metallation derivatives of the sodium dialkyl(amido)zincate reagent (TMEDA)Na(μ‐TMP)Zn(^tBu)₂ (TMEDA is N,N,N′,N′‐tetramethylethylenediamine and TMP is 2,2,6,6‐tetramethylpiperidide) have been of structural interest due to the insight they give into aromatic metallation mechanisms. Here, the aromatic substrate is formally replaced with [ZnO]₂ to give tetra‐tert‐butyldi‐μ₄‐oxido‐bis(tetramethylethylenediamine‐κ²N,N′)bis(μ₂‐2,2,6,6‐tetramethylpiperidin‐1‐ido‐κ²N:N)disodiumtetrazinc hexane 0.59‐solvate, [Na₂Zn₄(C₄H₉)₄(C₉H₁₈N)₂O₂(C₆H₁₆N₂)₂]·0.59C₆H₁₄. The crystallographically centrosymmetric complex retains many of the structural features of its parent monomer but has an unusual dimeric structure, with a central planar Zn–O–Zn–O ring joined to two orthogonal near‐planar Zn–O–Na–N rings through the distorted tetrahedral geometries of the oxide ions.     

Crystallographic characterisation of binary alkali metal alkoxide-magnesium bis(alkyl) mixtures: differential binding of Na+ and K+ to a common dinuclear diorganomagnesiate

Relevant to mixtures studied in solution and utilised in styrene polymerisation but hitherto not characterised in the solid, two crystal structures of alkali metal alkoxide-magnesium bis(alkyl) co-complexes have been determined, revealing that in binding to the C2O tripodal face of a common organomagnesiate anion, Na+ prefers O-coordination, whereas K+ prefers C-coordination.