Sodium bis(ethylenediamine)copper(II) tetracyanidocuprate(I)

The title compound, Na[Cu(en)2][Cu(CN)4], where en represents ethylenediamine, NH2CH2CH2NH2, crystallizes as a salt with two distinct cations, Na+ and [CuIIen2]2+, and discrete [CuI(CN)4]3− anions. The anion geometry is tetrahedral, with angles at the copper atom ranging from 105.0 (1) to 115.4 (1)°. The Cu—C distances are in the range 1.976 (3) to 1.993 (3) Å. The divalent copper atom is coordinated by four N atoms of the two bidentate en ligands in a slightly distorted square-planar geometry. In the crystal, each sodium ion interacts with cyanide N atoms of four different anions, with Na—N distances lying in the narrow range of 2.344 (3) to 2.367 (3) Å, and an approximately tetrahedral arrangement around the sodium ions. The interacting sodium ions and [CuI(CN)4]3− anions form a three-dimensional network with channels which contain the [Cu(en)2]2+ cations. One of the chelate rings in the cation shows partial disorder between two different conformations and the C atoms were refined with occupancies in the ratio 0.817 (15):0.183 (15).