Synthesis, structure and magnetic properties of a pentanuclear Cu(II) coordination polymer with 4-(imidazol-1-yl)-benzoic acid

A novel coordination polymer, [Cu5(IBA)4(N3)2(SO4)2]·4H2O (1) (HIBA = 4-(imidazol-1-yl)-benzoic acid), has been synthesized under hydrothermal condition, and characterized by elemental analysis, IR and single-crystal X-ray diffraction. X-ray single-crystal structural analyses reveal that complex 1 exhibits a two-dimensional layer structure based on pentanuclear Cu(II) clusters, and further assembled into a three-dimensional supramolecular structure via weak intermolecular interaction with one-dimensional open channels, in which the lattice water molecules are located. Moreover, variable-temperature magnetic susceptibility studies indicate dominant ferromagnetic interactions within the pentanuclear cluster.