Modification of Structure and Magnetic Properties in Coordination Assemblies Based on [Cu(cyclam)]2+ and [W(CN)8]3−

Abstract

The 1D {[CuII(cyclam)]3[WV(CN)8]2.5H2O}n (1·5H2O) (cyclam = 1,4,8,11-tetraazacyclotetradecane) coordination polymer of ladder topology can be obtained in water-alcohol solution from [Cu(cyclam)]2+ and [W(CN)8]3− building blocks. Upon dehydration, 1·5H2O undergoes a single-crystal-to-single-crystal structural transformation to the anhydrous {[CuII(cyclam)]3[WV(CN)8]2}n (1) form, which retains the same topology, but is characterized by shorter Cu-W distances and significantly more bent CN-bridges. The deformation of the coordination skeleton is reflected in magnetic properties: the predominant intra-chain interactions change from ferromagnetic in 1·5H2O to antiferromagnetic in 1. The reaction between the same building blocks in water solution under slow diffusion conditions leads to the formation of a 0D {[CuII(cyclam)(H2O)]2[CuII(cyclam)][WV(CN)8]2}.3H2O pentanuclear assembly (2·3H2O).

Keywords

• molecular magnetism
• octacyanotungstate(V)
• copper(II)
• cyclam
• cyano bridge
• magnetic properties