catena-Poly[sodium-μ2-(N,N,N′,N′-tetramethylethane-1,2-diamine)-κ2N:N′-sodium-bis[μ2-bis(trimethylsilyl)azanido-κ2N:N]]

The title compound, [Na2(C6H18NSi2)2(C6H16N2)]n, was found to consist of dimeric [Na(NSiMe3)2] units with crystallographically imposed centrosymmetry based upon four-membered NaNNaN rings. The dimers are bridged by N,N,N′,N′-tetramethylethylenediamine ligands, which act in an unusual extended non-chelating coordination mode. This gives a one-dimensional coordination polymer that extends parallel to the a-axis direction.