Synthesis, characterization and magnetic properties of a hexanuclear copper (II) complex with hydroxido, alkoxido and phenoxido bridges

A new Cu^II₆ complex, formulated as [Cu₆(L)₃(µ₃-OH)(H₂O)(OH)(NO₃)]·2H₂O·7CH₃OH (1) has been prepared using the symmetrical N₂O₃-donor Schiff-base ligand H₃L = N,N′-(2-hydroxypropane-1,3-diyl)bis(2-hydroxyacetophenimine). Compound 1 has been structurally and spectroscopically characterized. Single crystal X-ray diffraction analysis reveals that 1 crystallizes in the triclinic space group P-1 and consists of a Cu^II₆ complex where each deprotonated ligand chelates two Cu^II centres. Three of the six independent Cu^II centres are arranged in an almost equilateral triangle with double Cu-O-Cu bridges, formed by a μ₃-hydroxido and phenoxido bridges. Each of the three Cu^II centres in the triangle is further connected to one Cu^II centre through a single alkoxido bridge. The magnetic properties indicate the presence of moderate and weak antiferromagnetic interactions through the double and single oxido bridges, respectively.