A novel three-dimensional coordination polymer containing tetranuclear [Co4(μ3-OH)2] building blocks: Synthesis, crystal structure and magnetic behavior of {[Co2(btc)(μ3-OH)(H2O)2] · H2O}n

A cobalt coordination polymer {[Co2(btc)(μ3-OH)(H2O)2] · H2O}n 1 (btc = 1,2,4-benzenetricarboxylate) was synthesized hydrothermally and structurally characterized by single-crystal X-ray diffraction method. In 1, the six-coordinated Co(II) ions are held together by two bridging hydroxides to form a tetranuclear [Co4(μ3-OH)2] unit, which are connected further through btc3− ligands in a new μ7-bridging mode to give a porous three dimensional framework. The study of magnetic properties indicated dominant antiferromagnetic coupling interactions between the adjacent Co(II) sites.