Preparation, structural characterisation, and magnetic properties of [Cu(men)_2][Cu_2Cd_2Cl_2(CN) _6] (men = N-methylethane-1,2-diamine)

摘要

The novel complex [Cu(men)_2][Cu_2Cd_2Cl _2(CN)_6] (I) was isolated from the aqueous-ethanol system containing CuCl_2, men (men = N-methylethane-1,2-diamine) and K _2[Cd(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 [Cd _2Cl_2(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) ?) 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) ?) with chlorido ligands from the skeleton. The Cu(I) and Cd(II) atoms in the skeleton exhibit tetra-(CuC _4 chromophore) and penta-coordination (CdN_3Cl _2), respectively. The temperature-dependent susceptibility measurements indicate a Curie-Weiss-like behaviour and the presence of weak anti-ferromagnetic interaction.