Interlayer inclusion of tetracyanonickelate anion and water molecules: The crystal and molecular structure of [-ZN(en) 2 -μ-(NC) 2 -NI-μ -(CN) 2 -ZN(en) -] n 2 n + · n [NI(CN) 4 ] 2− · 3 n H 2 O

The crystal structure of [Zn(en)2- (NC)2Ni(CN)2 Zn(en)][Ni(CN)4]· 3 H2O consists of infinite positively charged wave-shaped layers of composition [Zn(en)2-(NC)2Ni(CN)2- Zn(en)] n 2n+ with the [Ni(CN)4]2− anions and water molecules included between them. Both Ni atoms exhibit square-planar coordination. The chelate bonded en (=ethylenediamine) and N-bonded cyano ligands around two independent zinc atoms form a deformed tetrahedron and a deformed octahedron, respectively. Yellow needles of the complex belong to the orthorhombic space groupPbcm witha = 6.977(1),b = 25.407(4),c = 14.876(2)Å,Z = 4,Dm = 1.74(1) g cm−3 andDc = 1.739 g cm−3. The structure was refined toR = 6.31 %.