Synthesis, structure and magnetic properties of 5-(4-Sulfophenylazo) salicylate-bridged 1D coordination polymers containing linear trinuclear metal clusters

Three new trinuclear metal complexes with an azobenzene-containing ligand [M3(Sasa)2(Py)2(H2O)8] (Na2HSasa = 5-(4-Sulfophenylazo) salicylic acid disodium salt; Py = pyridine; M = Cu, Co, Zn), are synthesized through the interface diffusion and structurally characterized by single crystal X-ray diffraction, XRPD analysis and spectral methods. The metal ions in distorted octahedral coordination environments are connected by Sasa ligands to form 1D coordination polymer chain containing the linear trinuclear units with single syn–anti carboxylate bridges. The extensive hydrogen bonding interactions hold these chains together into 3D supramolecular network. Weak antiferromagnetic interactions between adjacent metal ions with J = −1.85 cm−1 and J = −2.81 cm−1 dominate the magnetic properties of Cu(II) and Co(II) complexes, separately.