Polynuclear complexes incorporating Cu(II) and Mn(II) centers bridged by acetylenedicarboxylate: Structure, thermal stability and magnetism

Two acetylenedicarboxylate complexes, [Mn2(C4O4)(phen)4(H2O)2](ClO4)2·H2O (1) and [Cu(C4O4)(2,2′-bpy)]n (2), have been synthesized and characterized by elemental analyses and IR spectra. MnII ions have distorted octahedral coordination geometry and bridged by C4O42− to form a binuclear structure. Thermal analysis shows C4O42− released in the range of 180–280 °C. CuII is five-coordinated by 2,2′-bipyridine and three oxygen atoms from three different C4O42− ligands, leading to a square-pyramidal coordination geometry. Each C4O42− links three CuII centers through bifunctional carboxylate to form a polymeric structure of (4, 4) layers with nodes being dimer of Cu2O2 and bridges of C4O42−. Its variable-temperature magnetism was also investigated.