Secondary ligand-directed assembly of Co(II) coordination polymers based on a pyridine carboxylate ligand

To investigate the influence of hydrogen bonds and secondary ligands on the structures and properties of the resulting frameworks, five new Co(II) compounds have been synthesized by the reactions of Co(II) salts and 3,5-bis(pyridin-4-ylmethoxy)benzoic acid (HL) with four rationally selected dicarboxylic acid ligands. Without secondary ligand, we got one compound [CoL2(H2O)(2)](n) center dot 2nH(2)O (1), which possesses a 1D chain structure. In the presence of ancillary ligands, namely, 1,3-adamantanedicarboxylic acid (H(2)adbc), terephthalic acid (H(2)tpa), thiophene-2,5-dicarboxylic acid (H(2)tdc) and 1,4-benzenedithioacetic acid (H(2)bdtc), four 3D structures [Co2L2(adbc)](n)center dot nH(2)O (2), [Co2L2(tpa)](n) (3), [Co2L2(tdc)](n) (4), [Co2L2(bdtc)(H2O)](n) (5) were obtained, respectively. It can be observed from the architectures of 1-5 that hydrogen bonds and secondary ligands both have great effects on the spatial connective fashions, resulting in the formation of various dimensional compounds. The XRPD, TGA data of title polymers and the magnetic properties for 2 and 5 have also been investigated. (C) 2014 Elsevier Inc. All rights reserved.