Synthesis, structural characterization and anion-sensing studies of metal(II) complexes based on 3,3′,4,4′-oxydiphthalate and N-donor ligands

Using a multicarboxylate ligand, 3,3 ',4,4 '- oxydiphthalic acid (H(4)ODPA), and N-donor ligands, five metal(II)-ODPA complexes formulated as Cu-4(ODPA)(2)(L1)(4)(H2O)(10)center dot 2H(2)O (L1 = 4-(2-(pyridin-4-yl)vinyl)pyridine) (1), Co(H(2)ODPA) (L1)(H2O) (2), Zn-2(ODPA)(2)(H2PIP)(2)center dot H2O (PIP = 1,3-bis(4-piperidinyl)propane) (3), Mn-2(ODPA)(phen)(H2O)(2)(phen = phenanthroline) (4) and Cu-2(H(2)ODPA)(2)(phen)(4)center dot H2O (5) have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 shows a three dimensional (3D) framework with an unprecedented (4.6(4).8)(2)(4(2).6(4)) topology generated by the polycatenation of 2D layers. Complex 2 exhibits a uninodal 4-connected 3D architecture with 6(5)8-cds topology. Complex 3 shows a uninodal 2D layer with 4(4)-sql topology. Complex 4 has a binodal (4,6)-connected non-interpenetrated 3D architecture with (3.4(3).5.6)(3(2).4(3).5(4).6(4).7(2)) topology. Complex 5 is a mononuclear Cu(II) complex. Complexes 1 and 5 can irreversibly and reversibly detect SCN-, Cl-, Br- and I- in water, respectively. Complexes 2-4 are not feasible candidates for colorimetric detection of anions in aqueous solution. The metal(II) species and the structure of the metal complex play important roles in the colorimetric detection.