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(mu(2)-AZPY)(H2BTC)(2)]}. (1) and {[Cu(mu(2)-AZPY)(mu(2)-FIBTC)(H2O)]. 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 mu(eff) = 4.97 mu(B) for I and mu(eff) = 339 mu(B) for 2 at T = 290 K to the values of mu(eff) = 1.41 mu(B) for 1 and mu(eff) = 127 mu(B) for 2 at T = 2 K.
The origin of the observed behavior is discussed.