Ligand-directed and solvent-controlled assembly of six novel functional supramolecular metal-organic frameworks

Six novel functional metal-organic frameworks, namely, [CdCl(IP)(Hpydc)(H2O)]center dot 2H(2)O (1), [Cd(IP) (H(2)imdc)]Cl (2), [Cd(IP)(2)(H2O)(2)](1,5-nds)center dot 2H(2)O (3), [Co(IP)(H2O)(4)](1,5-nds)center dot H2O (4), [Zn(IP)(mu(2)-SO4) (H2O)]center dot H2O (5), [Zn(IP)(SO4)(H2O)(3)] (6) (IP = 1-H-imidazo[4,5-f][1,(1) over bar0]-phenanthroline, H(2)pydc = pyridine-2,6-dicarboxylic acid, H(3)imdc = imidazole-4,5-dicarboxylic acid, 1,5-nds = 1,5-naphthanlenedisulfonate), were synthesized by controlling auxiliary ligands, metal centers and solvents. In compound 1, Cd(II) is chelated by IP and Hpydc ligands, forming OD -> 3D supramolecular structure. Compound 2 is a 1D chain with repeated [Cd(IP)](2+) units connected by H(2)imdc ligands. With different metal centers, compounds 3 and 4 possess different crystal structures. With solvents regulated, compounds 5 and 6 exhibit distinct structures. In compound 5, sulfate anions show mu(2)-bridging mode, which results in the formation of 1D chain. In compound 6, only one oxygen atom from sulfate anion coordinates to the metal center, resulting in discrete repeated units. The luminescent properties of 1, 2, 3, 5, 6 and thermal stabilities of all compounds were measured. (C) 2012 Elsevier B.V. All rights reserved.