catena-Poly[tris(μ3-acetylacetonato)nickelate(II)sodium(I)].

The title complex, [NaNi(C5H7O2)3]n, contains an anionic tris(acetylacetonato)nickelate(II) unit, [Ni(acac)3](-) (acac is acetylacetonate), with a highly regular octahedral coordination geometry. The Ni(II) cation lies on a Wyckoff a site, resulting in D3 symmetry of the anion. Charge balance is provided by sodium cations, which occupy Wyckoff type b sites. Each sodium cation is surrounded by two [Ni(acac)3](-) anions, each of which is connected to the alkali metal through three O atoms, in a fac configuration. This arrangement leads to the formation of linear [Na{Ni(acac)3}]n chains along the c axis. The Ni···Na distance is 2.9211 (10) Å. The title complex is one of the few examples of heterometallic systems based on alkali and transition metal cations bridged by acetylacetonate ligands.