Amidolithium complexes

Overall, the ability of primary amidolithium complexes to form such a wide range of architectures can be considered as a consequence of the relatively small steric demands of the N(H) unit. These complexes therefore possess a combination of characteristics of secondary amidolithium complexes and the sterically less encumbered imidolithium species previously reviewed in GOMG (1995).7... 

Amidolithium complexes of type RR NLi (e.g. R and R = alkyl, aryl, silyl) exhibit a fascinating structural diversity as above, bulky amido ligands are essential for complex stabilization. Planar Li2N2-rings are common structural units, and these appear in a variety of laddered structures which may be polymeric or discrete molecular as in [ BuHNLijgj (Figure 10.10). 

III. Simple Lithium Amides (Amidolithiums) and Their Complexes Ring Laddering... 

The effect of solvation by Lewis base donor solvents is to reduce this complexity. THE, the most widely used solvent for these bases, forms bis-solvated dimeric complexes with most amidolithiums, since this smallest Li2N2 ring provides maximum room for the additional donor molecules. Chelating donors may even produce monomers, but ion separation is found in the solid state only when the anion is stabilized by electron-accepting heteroatoms. 

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