Abstract

A new family of cadmium(II) coordination polymers, {[Cd(Hbic)₂·(H₂O)₂]·2H₂O}_n (1), [Cd(Hbic)₂]_n (2), [Cd(Hbic)₂·(H₂O)]_n (3), H₂bic = 1H-benzimidazole-5-carboxylic acid, has been hydrothermally prepared by the assembly of Cd^II with H₂bic. A change in the pH values resulted in a series of compounds with different compositions and dimensionalities. Formed at the lowest pH, compound 1 has a two-dimensional supramolecular structure, which contains 1D chains extended by hydrogen bonds. At a slightly higher pH, compound 2 is synthesized with a higher number of deprotonated carboxylate groups per cadmium atom. A further increase in the pH leads to 3D dinuclear compound 3 with yellow-green emitting fluorescence. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Two complexes with double- or triple-stranded chain structures, {[Cd(pg)(phen)]·3H₂O}_n (1) and {[Cd₃(cpg)₃(phen)₂]·3H₂O}_n (2), have been hydrothermally synthesized [H₂pg = 3-phenylglutaric acid, H₂cpg = 3-(4-chlorophenyl)glutaric acid, phen = 1,10-phenanthroline]. In the crystal lattices of 1 and 2, two 1D polymeric water morphologies are observed (a treelike chain for 1 and a staircaselike tape for 2), both of which contain (H₂O)₆ subunits. The geometrical parameters of water chains and tapes are similar to those in ice, I_h, and liquid water, respectively. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Four novel multidimensional coordination polymers, {[Cd(3-PYD)₂(H₂O)]·2H₂O}_n (1), [Pb(3-PYD)₂]_n (2), {[Cu_1.5(3-PYD)₃(H₂O)]·1.5H₂O}_n (3) and [Zn(3-PYD)₂(H₂O)₂]_n (4), have been hydrothermally synthesized from 3-(3-pyridyl)acrylic acid (3-HPYD). In 1, 3-PYD in a head-to-head arranged fashion bridges Cd^II, generating a two-dimensional layer, which is further extended into a three-dimensional supramolecular network by hydrogen-bonding interactions. Compound 2 shows a two-dimensional wave-like layer that consists of {Pb(3-PYD)}₄ rings from head-to-tail arranged 3-PYD. Compound 3 is a twofold interpenetrating three-dimensional network consisting of {Cu(3-PYD)}₆ rings formed through the mixed head-to-head and head-to-tail arrangements of 3-PYD. However, 4 is a three-dimensional supramolecular framework constructed by one-dimensional zinc-3-PYD chains through hydrogen-bonding interactions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Self-assembly reactions of 5-sulfoisophthalic monosodium salt (NaH₂sipa), Cd(NO₃)₂·4H₂O and 2,2'-bipyridine (or 4,4'-bipyridine) under hydrothermal condition give rise to four polymeric complexes, namely {[Cd₃(sipa)₂(2,2'-bpy)₄(H₂O)₂]·6H₂O}_n (1), {[Cd(sipa)(H-4,4'-bpy)(H₂O)]·2H₂O}_n (2); {[Cd₂(sipa)(4,4'-bpy)₃(H₂O)₃]·[Cd(sipa)(4,4'-bpy)(H₂O)]·8H₂O}_n (3),and {[Cd₃(sipa)₂(4,4'-bpy)₄(H₂O)₂]·3H₂O}_n (4), respectively. X-ray diffraction analyses reveal that complex 1 possesses a 1D rail-like chain structure, 2 is a 1D double chain, 3 has a 2D network consisting of an independent [Cd₂(sipa)(4,4'-bpy)₃(H₂O)₃]_nⁿ⁺ cationic layer and a [Cd(sipa)(4,4'-bpy)(H₂O)]_n^n– anionic layer, and 4 is a novel 3D self-penetrating network constructed from two mixed bridging ligands. Thermogravimetric analyses (TGA) and fluorescent measurements of complexes 1–4 have also been performed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

A new octadentate ligand L was synthesized by tetrafunctionalization of 1,4,8,11-tetraazacyclotetradecane (L¹, cyclam) with 4-pyridylmethyl groups and its two novelcadmium polymeric metallamacrocyclic complexes, [Cd₃L_1.5(C₆H₅O₇)₂·6H₂O]_n (1) and [CdCl₂L₂·2.5H₂O]_n (2), were obtained by hydrothermal methods. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

The assembly of 5-sulfoisophthalic acid (H₃sipa) and 4,4′-bipyridine (bpy) with Cd²⁺ ions gave rise to a new polymeric complex {[Cd₃(sipa)₂(bpy)₄(H₂O)₂]·3H₂O}_n (1). X-ray diffraction analysis reveals that complex 1 has a 3-D self-penetrating network formed by the interlocking and interweaving of two types of one-dimensional chains comprising two kinds of Cd₄(sipa)₄ and Cd₄(bpy)₄ units, respectively. The sipa³⁻ ligand serves as the connector and the Cd²⁺ ion as the node. Thermogravimetric analysis (TGA) and the luminescence property of 1 are discussed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Self-assembly reactions of sulfonates with AgNO₃ in the presence of secondary N- or P-containing ligands result in the formation of four new silver-sulfonate polymers, [Ag(PIP)]_n·[Ag(pesp)]_n·2nH₂O (1), [Ag₂(pesp)(dabco)]_n·5nH₂O (2), [{Ag(pesp)_1/2(hmt)_1/4}·0.5H₂O]_n (3) and [Ag(PPh₃)(pesp)_1/2]_n·nMeOH (4), whose structures change from one-dimensional chains to three-dimensional open frameworks based on the secondary ligands. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Hydrothermal reaction of1,2,4-benzenetricarboxylic acid, and MnCl₂4H₂O with1,10-phenanthroline gave the title complex, [Mn(phen)(m-phth)]_n, which crystallizes in the monoclinic system, space group P2/c with a= 0.83582(3) nm, b=1.04246(4) nm, c=1.87777(7) nm, β= 100.314(2), V=1.60%8(10) nm³, Z=4, and the final R =0.0576, wR =0.1294. In the complex, each Mn(II) ion is coordinated to four O atoms of carboxylate groups and two N atoms of phen. Isophthalate was generated in situ through the loss of one carboxylate group of1,2,4-benzenetricarboxylic acid under the hydrothermal condition. Each isophthalate is bound to three manganese atoms through O atom of carboxylate in bridging and chelating fashion, affording manganese(II) pairs that are linked by the isophthalate group to yield a zig-zag chain along the c-axis.

The title complex, [La(btec)_1/2(H₂btec)_1/2 (H₂O)]_n (H₄btec= 1, 2,4,5-benzenetetracarboxylic acid) (1) was synthesized by the hydrothermal reaction of 1,2,4,5-benzenetetracarboxylic dianhydride with La(NO₃)₃·6H₂O in H₂O, and crystallizes in the triclinic system, space group P-1 with a = 0.64403(3) nm, b = 0.94500(4) nm, c = 0.96380(5) nm, a = 88.535(2)°, β = 100.314(2)°, γ = 76.6470(10)°, V = 1.60968(10) nm³, Z = 2, and final R = 0.0274, R_w = 0.0735. In 1, each La(m) ion is coordinated by eight oxygen atoms from six carboxylate groups and one coordinated water molecule. Two different coordination modes of H₄btec were present in the structure, one of which contains two protonated carboxylate groups to balance the charge.

A new silver (I) coordination polymer, [Ag(hmt) (fma)_1/2 · 2H₂O]_n (1), (hmt = hexamethylenetetramine, fma = furmaric acid), was obtained by self-assembly of hmt, fma and AgNO₃ in the mixed solvent of methanol, dichloromethane and water (CH₃OH:CH₂Cl₂:H₂O = 5:5:1), and characterized by X-ray diffraction analysis. Complex 1 belongs to orthorhombic space group Pbcn with cell parameters a = 1.72043(5) nm, b=1.19704(2) nm, c = 1.11685(3) nm, V = 2.30007(10) nm³, Z = 8, CCDC number: 194381. In complex 1, each hmt ligand acts as a μ₃-bridge to link three Ag(I) atoms and in turn every Ag(I) ion attaches to three hmt ligands to produce a 2D honeycomb network, which is further linked by the bidentate fma ligands to form a 3D noninterpenetrating open framework with one-dimensional channels being filled by guest molecules.