Connected 3D Network Research Articles

New metal complexes with 5-(1H-imidazol-4-ylmethyl)aminoisophthalic acid: Syntheses, structures, electrochemistry and electrocatalysis

Three new coordination polymers {[Cu(HL)(H 2O)]·H 2O} n ( 1), [Ag(H 2L)] n ( 2), and {[Co(HL)(phen)(H 2O)]·8H 2O} n ( 3) [H 3L = 5-(1H-imidazol-4-ylmethyl)aminoisophthalic acid, phen = 1,10-phenanthroline] have been synthesized under hydrothermal conditions. The results of X-ray diffraction analysis revealed that complex 1 displays (3, 3)-connected 2D network with (4, 8 2) topology, while complexes 2 and 3 have infinite 1D chain structure, in which one of the two carboxylic groups of H 2L −/HL 2− is uncoordinated. The 2D layers of 1 or the 1D chains of 2 and 3 are further linked together by hydrogen bonds and π–π interactions to form 3D supramolecular frameworks. Moreover, the electrochemical properties of complexes 1 and 2 have been studied by modified glassy carbon electrodes of 1 (Cu-GCE) and 2 (Ag-GCE), and the results indicate that the Cu-GCE and Ag-GCE show one-electron redox peaks. In addition, both Cu-GCE and Ag-GCE have good electrocatalytic activities toward the reduction of H 2O 2 in phosphate buffer (pH 5.5) solution.

New metal–organic architectures of cobalt(II), nickel(II) and zinc(II) with tripodal ligand 5-(1H-imidazol-4-ylmethyl)aminoisophthalic acid

Four new coordination polymers {[Ni(HL)(H 2O)]·H 2O} n ( 1), {[Co(HL)(H 2O)]·H 2O} n ( 2), {[Co(HL)]·4H 2O} n ( 3) and {[Zn(HL)]·2H 2O·0.5C 2H 5OH} n ( 4) [H 3L = 5-(1H-imidazol-4-ylmethyl)aminoisophthalic acid] have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction analyses. Complexes 1 and 2 display (3, 3)-connected 2D network with (4, 8 2) topology. While 3 and 4 exhibit a binodal (3, 6)-connected 2D network with a Schläfli symbol (4 3) 2(4 6, 6 6, 8 3). The complexes 1– 4 show remarkable thermal stability and 4 exhibits blue fluorescence with maximum emission at 413 nm upon excitation at 362 nm in the solid state at room temperature. In addition, the magnetic measurements of 3 indicate that there are antiferromagnetic interactions between the neighboring Co(II) centers.

2D and 3D networks of lanthanide with mixed dicarboxylate ligands: syntheses, crystal structures and photoluminescent properties

A series of lanthanide complexes with mixed polycarboxylate ligands, [Ln2(op)2(ox)(H2O)4]n·nH2O (Ln = Ce, Pr, Nd, Sm, Eu and Gd for 1–6, respectively), [KLn(pma)1/2(ox)(H2O)]n (Ln = Tb (7) and Dy (8)), [KLn2(mp)3(ox)1/2(H2O)3]n (Ln = Ce(9) and Pr(10)) (op = o-phthalate, ox = oxalate, pma = pyromellitate and mp = m-phthalate), have been prepared, and their photoluminescent properties have been investigated. Compounds 1–6 show (3,4)-connected 2D network structures consisting of {Ln(op)}n staircase chains bridged by ox ligands. Compounds 7 and 8 consist of 1D zigzag {Dy(ox)}n chains linked by pma ligands adopting a new μ4-hexadentate coordination mode to form 2D 6-connected networks with (36·46·53) topology. Through K⋯O interactions, the 2D networks are further connected to construct 3D structures. Compounds 9 and 10 display inorganic–organic 3D topology networks with the Schlafli symbol (3·43·52)(32·410·59·614·7)(42·5) containing mixed (3,4,9)-connected nodes.

A coordination polymer with a (3,4)-connected (4·62)2(42 ·62 ·82) 2D network: synthesis, crystal structure and luminescent properties

The 2D Zn(II) coordination polymer with 2,3-dicarboxypyridine acid (2,3-H2PDC) and dimethylamine (DMA) [Zn(2,3-PDC)(DMA)] n (1) was synthesized under solvothermal conditions and characterized by FT-IR spectroscopy, TGA and luminescent analysis. X-ray crystallographic studies of 1 reveal that this metal-organic complex has an interesting (3,4)-connected 2D network with binary nodes. The Zn ions are four-connected nodes and the 2,3-PDC ligands are three-connected nodes. Luminescent study indicates 1 has an emissive maximum at 403 nm in the solid state at room temperature.