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

Abstract An ether bridged tetracarboxylic acid ligand, 5-(3′,4′-Dicarboxylphenoxy)-isophthalic acid (H 4 L) 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 L(4,4′-bpy) 2 (H 2 O) 3 ] n ( 1 ) and {[Co(bpbp) 2 (H 2 L)]·H 2 O} 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)(H 2 L)] 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.