Aggregates lithiated carbons

Figure 13 Typical spin multiplets of the lithiated carbon from simple alkyllithium aggregates showing C, Li coupling (a) phenyllithium monomer (—100°C) (b) n-butyllithium dimer (—100°C) (c) /ert-butyllithium tetramer (—88°C) the coupling constants are 14.8, 7.9, and S.4Hz, respectively...

Subtle structural differences have been observed in some dimers of lithiated 1,3-bis[(dimethylamino)alkyl]benzenes [14]. Direct lithiation of l,3-bis[(dimethylami-no)ethyl]henzens with H-butyllithium produced a symmetric dimer, in which the coordination sphere of lithium was saturated by coordination of the chelating amino substituents. An analogous lithiation reaction performed between 1,3-bis[(dimethylamino)/ ro 7y/]benzene and n-butyllithium yielded a mixed dimeric aggregate comprising the expected phenyllithium derivative and nBuLi in a 1 1 molar ratio. In the molecular structure four lithium ions and four bridging carbon atoms form a ladder-type framework. 

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