catena-Poly[[(N,N-di­methyl­cyanamide-κN)lithium]-μ(3)-bromido]

The title complex, [LiBr(C(3)H(6)N(2))](n), is the unexpected product of a reaction beteween (Dipp)N(Li)SiMe(3) (Dipp = 2,6-diiso­propyl­phen­yl), Me(2)NCN and CuBr. The compound is a one-dimensional polymer with a step structure derived from the association of inversion dimers, formed by bromido ligands bridging two Li(+) cations, each of which carries a di­methyl­cyanamide ligand. The planar (LiBr)(2) unit of the polymer core has a regular rhombic shape [Li—Br—Li 77.55 (16)° and Br—Li—Br 102.45 (16)°]. These (LiBr·NCNMe(2))(2) dimers represent the repeat unit of a polymer system propagated by additional Br—Li and Li—Br bonds generating an infinite step structure along the a-axis direction.