Preparation, structural characterisation, and magnetic properties of [Cu(men)2][Cu2Cd2Cl2(CN)6] (men = N-methylethane-1,2-diamine)

The novel complex Cu(men)₂]Cu₂Cd₂Cl₂(CN)₆] (I) was isolated from the aqueous-ethanol system containing CuCl₂, men (men = N-methylethane-1,2-diamine) and K₂Cd(CN)₄] in the presence of dilute hydrochloric acid and chemically and spectroscopically characterised. The crystal structure of I consists of Cu ₂ ^I (CN)₆] and Cd₂Cl₂(CN)₆] building units bridged by cyanide ligands and forms a three-dimensional skeleton with cavities. Cu(men)₂]²⁺ cations in which two men ligands are chelated (mean Cu-N is 2.033(6) Å) are located in the cavities. The coordination polyhedron around the Cu(II) atoms is formed as a tetragonal bipyramidal by two weaker axial Cu-Cl bonds (2.8642(12) Å) with chlorido ligands from the skeleton. The Cu(I) and Cd(II) atoms in the skeleton exhibit tetra-(CuC₄ chromophore) and penta-coordination (CdN₃Cl₂), respectively. The temperature-dependent susceptibility measurements indicate a Curie-Weiss-like behaviour and the presence of weak anti-ferromagnetic interaction.