Structural diversities and related properties of four coordination polymers synthesized from original ligand of 3,3 ',5,5 '-azobenzenetetracarboxylic acid

摘要

Four new coordination polymers, namely [Co(H(2)O(2)abtc)(bibp)](n) (1), {[Mn-1.5(Oabtc)(H2O)(2)]center dot(H(2)bmib)(0.5)center dot H2O}(n) (2), {[Cd-1.5(O(2)abtc)]center dot(H(2)bmib)0.5 center dot 2H(2)O}(n) (3), and {[Cd(nip)(bibp)]center dot 0.5H(2)O}(n) (4), were constructed under solvothermal conditions in the presence of two bis(imidazole) bridging linkers (bimb = 1,4-bis( 2-methylimidazol-1-ylmethyl) benzene, bibp = 4,4'-bis(imidazol-1-yl) biphenyl). The unstable azo ligand of 3,3', 5,5'-azobenzenetetracarboxylic acid (H(4)abtc) could be oxidized and resulted in three oxidized derivatives of H(4)Oabtc (one N atom was oxidized), H(4)O(2)abtc (two N atoms were oxidized), and H(2)nip (one H(4)abtc was oxidized to two 5-nitroisophthalic acids). Their structures were determined by singlecrystal X-ray diffraction and further characterized by elemental analyses, IR spectroscopy, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analysis. Complex 1 exhibited an interestingly 2D + 2D -> 3D parallel entangled network based on 4-connected (4(4).6(2))-sql sheets. Complex 2 was found to be a {Mn-3(COO)(6)} trinuclear SBU based 2D (3,6)-connected (4(3))(2)(4(6).6(6).8(3))-kgd sheet. While complex 3 displays a {Cd-3(COO)(8)} trinuclear SBUs based 3D (4,8)-connected (4(6))(2)(4(12).6(12).8(4))-flu network. Complex 4 can be regard as a {Cd-2(COO)(2)} binuclear SBUs based 6-connected (4(4).6(11))-6T8 framework. In addition, the magnetic property of complexes 1, 2 and the luminescence properties of complexes 3, 4 were investigated.