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 ·0.5 n H 2 O ( 1 ), [Ni(phen)(oba)] n ·0.5 n H 2 O ( 2 ), [Co 2 (H 2 O)(TATP) 2 (oba) 2 ] n ·2 n H 2 O ( 3 ), and [Ni 2 (H 2 O)(TATP) 2 (oba) 2 ] n ·2 n H 2 O ( 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.