Supramolecular heteropolyme tallic assemblies constructed from binuclear complexes and hexacyanometallate anions. Synthesis, crystal structure and magnetic properties of [Cu2(fsal-33)(H2O)2]3[Fe(CN)6]2·8 H2O

Abstract

A supramolecular heteropolymetallic system, [Cu₂(fsal-33)(H₂O)₂]₃[Fe(CN)₆]₂·8 H₂O (1), was obtained by reacting K₃[Fe(CN)₆] with [Cu₂(fsal-33)(H₂O)₂](ClO₄)₂ (H₂fsal-33 is the symmetric macrocyclic binucleating Schiff base ligand obtained by condensation of 2,6-diformyl-4-methylphenol with 1,3-propylenediamine). The crystallographic investigation of 1 reveals a complex three-dimensional structure based on hydrogen-bond interactions between the aqua ligands coordinated to the copper atoms, the water molecules, and the cyano groups arising from the hexacyanoferrate(III) anions. The cryomagnetic measurements reveal the strong antiferromagnetic interaction between the copper(II) ions within the binuclear cationic entity, and the temperature dependence of the χ_MT product, which is due to the first-order orbital momentum associated with low-spin Fe(III).