Syntheses, crystal structures, and magnetic studies of two cobalt(II) coordination polymers based on concurrent ligand extension

An ether bridged tetracarboxylic acid ligand, 5-(3',4'-Dicarboxylphenoxy)-isophthalic acid (H4L) was used to construct two Co(II) coordination polymers in presence of different nitrogen donor ligands such as 4,4'-bipyridine (4,4'-bpy) and 4,4'-bis(pyrid-4-yl)biphenyl (bpbp). The products formed under hydrothermal conditions are formulated as [Co-2(4,4'-bpy)(2)(H2O)(3)](n), (1) and {[Co(bPbP)(2)(H2L)]center dot H2O}(n), (2). The compounds were characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis, and powder X-ray diffraction (PXRD) measurement. Compound 1 shows an intriguing (3,4,5)-connected 3D framework with a point symbol of (4(2) . 6(2) . 8(2))(4(2) . 6(5) . 8(3))(6(2) . 8). Compound 2 is an unusual 3D supramolecular framework generated by the one-dimensional [Co(bpbp)(H2L)](n) polymer chain. The magnetic properties of compounds 1 and 2 were examined, indicating antiferromagnetic interactions between the cobalt(II) ions in the temperature range of 2-300 K. (C) 2015 Elsevier B.V. All rights reserved.