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 [Cu^IIen₂]²⁺, and discrete [Cu^I(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 [Cu^I(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).