Characterization and magnetic properties of two novel copper(II) coordination polymers prepared by different synthetic techniques

Abstract Two novel ternary Cu(II) coordination polymers with formulas {[Cu(μ 2 -AZPY)(H 2 BTC) 2 ]} n ( 1 ) and {[Cu(μ 2 -AZPY)(μ 2 -HBTC)(H 2 O)]·AZPY} n ( 2 ) (AZPY – trans-4,4′-azobis(pyridine), BTC – benzene-1,3,5-tricarboxylate) have been synthesized using the solvothermal or diffusion techniques, respectively. Compounds were characterized by single crystal X-ray diffraction, thermogravimetry, infrared spectroscopy, elemental analysis and AAS. Removal of water and AZPY from the framework of 2 was investigated by wide-angle X-ray scattering measurements during in-situ heating. A magnetic study showed on antiferromagnetic coupling in 1 and 2 and magnetic properties may be influenced by both crystal field (CF) and inter-molecular interactions. The effective magnetic moment decreases from the values μ eff  = 4.97 μ B for 1 and μ eff  = 3.39 μ B for 2 at T = 290 K to the values of μ eff  = 1.41 μ B for 1 and μ eff  = 1.27 μ B for 2 at T = 2 K. The origin of the observed behavior is discussed.