Synthesis, Topological Analysis and Properties of a Coordination Polymer with Butane-1,2,3,4-tetracarboxylato-bridged (Phenanthroline)cobalt(II) Units

A hydrothermal reaction of Co(Ac)(2)center dot 4H(2)O, butane-1,2,3,4-tetracarboxylic acid (H(4)BTC), 1,10-phenanthroline (phen) and NaOH carried out at 160 degrees C yielded a new complex [Co(2)(H(2)O)(2)(phen)(2)(BTC)]. The complex has been characterized by single-crystal X-ray diffraction, IR spectroscopy, TG-DTA analyses, elemental analyses, powder X-ray diffraction, and magnetic measurements. The Co ions are linked by BTC(4-) anions into a chain, and hydrogen bonding and pi-pi stacking interactions result in the formation of a 3D (3,4,6)-connected supramolecular architecture with the Schlafli symbol (4(3).6(2).8)(2)(4(6).6(6).8(3))(6(3))(2). The temperature dependence of the magnetic susceptibility of the compound follows a Curie-Weiss law chi(m) = C/(T - Theta) with C = 4.18(4) cm(3) mol(-1) K and Theta = -1.43(5) K, and the magnetic behavior can be interpreted by means of a ID chain Fisher model, where the magnetic superexchange is transmitted via pi center dot center dot center dot pi stacking interactions between adjacent phen ligands, and the best fit results in J = -0.05 cm(-1), and zJ' = 0.21 cm(-1).