Synthesis and properties of a new (3,8)-connected pillar-layered Co(II)-based coordination polymer supported by tetranuclear secondary building units (SBUs)

An unusual three-dimensional Co(II)-based pillar-layered coordination polymer [Co2(L)(bipy)(OH)(H2O)]n·nCH3CN (1, H3L = 2-(2′,4′-dicarboxylphenoxy)benzoic acid, bipy = 4,4′-bipyridine), has been successfully yielded via the mixed ligand approach under hydrothermal condition, and characterized carefully by elemental analysis, infrared spectra, and single crystal X-ray diffraction, and magnetic measurement. Single crystal X-ray analysis reveals that the framework of complex 1 is firstly assembled by the 2D undulated layers, and then further supported by bipy spacers into a 3D intricate framework. Topologically, 1 shows a 3D binodal (3,8)-connected tfz-d net with the Schläfli symbol of (43)2(46·618·84), which is less common and rarely found in the reported literatures. Moreover, the magnetic analysis indicates that 1 exhibits the antiferromagnetic coupling interaction between Co(II) ions.