Effect of the Size of Aromatic Chelate Ligands on the Frameworks of Metal Dicarboxylate Polymers: From Helical Chains to 2-D Networks

To investigate the influence of the size of the aromatic chelate ligands on the frameworks of metal dicarboxylate polymers, four new coordination compounds [Co(phen)(oba)]n·0.5nH2O (1), [Ni(phen)(oba)]n·0.5nH2O (2), [Co2(H2O)(TATP)2(oba)2]n·2nH2O (3), and [Ni2(H2O)(TATP)2(oba)2]n·2nH2O (4) (phen = 1,10-phenanthroline, TATP = 1,4,8,9-tetranitrogen-trisphene, oba = 4,4‘-oxybis(benzoate)) have been synthesized under similar conditions and structurally characterized by elemental analysis, IR, and X-ray crystallography. In the isomorphous 1 and 2, the metal centers are linked by bridging oba ligand to form 1-D helical chains, whereas the isomorphous 3 and 4 have extended 2-D arrays. The differences among these structures indicate that the size of the rigid aromatic chelate ligands have important effects on the structures of their complexes.