Coordination polymer

About: Coordination polymer is a research topic. Over the lifetime, 11988 publications have been published within this topic receiving 212219 citations.

Magnetic Iron Oxide Nanoparticle Seeded Growth of Nucleotide Coordinated Polymers.

Abstract: The introduction of functional molecules to the surface of magnetic iron oxide nanoparticles (NPs) is of critical importance. Most previously reported methods were focused on surface ligand attachment either by physisorption or covalent conjugation, resulting in limited ligand loading capacity. In this work, we report the seeded growth of a nucleotide coordinated polymer shell, which can be considered as a special form of adsorption by forming a complete shell. Among all of the tested metal ions, Fe3+ is the most efficient for this seeded growth. A diverse range of guest molecules, including small organic dyes, proteins, DNA, and gold NPs, can be encapsulated in the shell. All of these molecules were loaded at a much higher capacity compared to that on the naked iron oxide NP core, confirming the advantage of the coordination polymer (CP) shell. In addition, the CP shell provides better guest protein stability compared to that of simple physisorption while retaining guest activity as confirmed by the entr...

Bringing 5-(3,4-dicarboxylphenyl)picolinic acid to crystal engineering research: hydrothermal assembly, structural features, and photocatalytic activity of Mn, Ni, Cu, and Zn coordination polymers

Abstract: 5-(3,4-Dicarboxylphenyl)picolinic acid (H3dppa) was applied as a novel tricarboxylic acid block with phthalate and picolinate functionalities for the aqueous-medium assembly of seven new coordination compounds, namely, [Mn2(μ-Hdppa)2(phen)2(H2O)2] (1), {[Mn(μ-Hdppa)(2,2′-H2biim)(H2O)]·H2O}n (2), [Ni(Hdppa)(phen)2]·4H2O (3), {[Ni(μ-Hdppa)(μ-4,4′-bipy)(H2O)]·H2O}n (4), {[Cu3(μ3-dppa)(μ-Hdppa)(phen)4]2[Cu(μ-Hdppa)2]·10H2O}n (5), {[Ni3(μ-dppa)2(μ-1,4-bpb)2(H2O)6]·4H2O}n (6), and {[Zn3(μ4-dppa)2(phen)2(H2O)2]·4H2O}n (7). These products 1–7 represent the first structurally characterized examples of the coordination compounds derived from H3dppa. Compounds 1–7 were assembled in the presence of various N-donor supporting ligands acting as crystallization mediators, which were selected from 1,10-phenanthroline (phen), 2,2′-biimidazole (H2biim), 4,4′-bipyridine (4,4′-bipy), or 1,4-bis(pyrid-4-yl)benzene (1,4-bpb). Full characterization of 1–7 by IR spectroscopy, thermogravimetric (TGA), elemental, and topological analyses, as well as powder (PXRD) and single-crystal X-ray diffraction, was performed. The structural types range from the discrete 0D complexes (1 and 3) and 1D coordination polymers with a 2C1 topology (2, 5, and 6) to the 2D metal–organic layers with an sql topology (4 and 7). The structural diversity of 1–7 is driven by various factors, including the metal(II) node nature, deprotonation degree of H3dppa, or type of crystallization mediator. The magnetic properties of 1, 2, 4, and 6 were studied and modeled, revealing antiferromagnetic (in 1, 2, and 6) or ferromagnetic (in 4) interactions between adjacent metal(II) centers. The luminescence of 7 was also investigated. Moreover, the photocatalytic activity of 1–7 was studied for the degradation of methylene blue as a model dye pollutant, disclosing that the nickel(II) coordination polymer 4 is the most active catalyst. The observed catalytic activity of 1–7 correlates well with their band gap energies determined by the UV-diffuse reflectance method.

Coordination and hydrogen bonded networks featuring 4,4′-dicarboxy-2,2′-bipyridine (H2dcbp): structural characterisation of H2dcbp, [Co(dcbp)(H2O)4]·4H2O, and {[Cu(dcbp)(H2O)2]·2H2O}n

Abstract: We report herein the single crystal structures of 4,4′-dicarboxy-2,2′-bipyridine, H2dcbp, and two complexes it forms with Co(II), [Co(dcbp)(H2O)4]·4H2O, 1, and Cu(II), {[Cu(dcbp)(H2O)2]·2H2O}n, 2. H2dcbp adopts the anti conformation in the solid-state, with a dihedral angle of 148° between each pyridyl ring. Face-to-face π⋯π interactions reinforce intermolecular hydrogen bonding (O–H⋯N) involving both carboxylate oxygen and pyridyl nitrogen atoms forming a 2D inter-helical network. Alternate 2D layers are of opposite chirality and are linked into 3D through (C–H⋯O) hydrogen bonds. In both 1 and 2 the ligand is deprotonated giving neutral complexes with 1 ∶ 1 stoichiometry. Although 1 is monomeric, extensive hydrogen bonding between the deprotonated carboxylates, lattice water, and coordinated water molecules results in a 3D network which also contains face-to-face π⋯π interactions between adjacent dcbp ligands. Within 2, pseudo-octahedral coordination about the Cu(II) centre is furnished by bidentate bipyridyl nitrogens, two monodentate carboxylates (from two adjacent dcbp ligands) and two water molecules. Coordination of dcbp in this instance forms a 2D coordination polymer, which is further linked by extensive hydrogen bonding between carboxylates and water molecules, giving a 3D network.

A Water Soluble Diruthenium–Gold Organometallic Microgel

Abstract: Selection of the combination of metal, ligand set, and spacer groups that are most appropriate to form a coordination complex with a desired function are of paramount importance in supramolecular chemistry. In particular, the establishment of reproducible methods to accomplish controlled selforganization of molecules to form polymers and homoor heterometallic coordination aggregates is an important field of research. Although important advances have already been made, few metallopolymers, which are one of the most exciting classes of functional materials, are water soluble. An important example of a water-soluble polymer is the polyferrocenylsilane-b-polyaminomethacrylate copolymer described by Manners and co-workers, as part of their ongoing study on metallocene-based polymers. Recent examples also include the water-soluble metallopolymer obtained by reaction of bipyridyl-appended poly(p-phenyleneethynylene) (PPEs) with metal ions in organic and aqueous solution. Other examples of ligands that afford coordination polymers with various topologies and applications are ferrocenyl groups bearing bipyridine (bpy) or carboxylate moieties. A recent example of a non-water-soluble multimetallic polymer is [Sm(H2O)5][Ru2(bpy)2(CN)7], in which the CN ligands bridge the samarium and ruthenium metal centers. The first air-stable water-soluble multimetallic polymer that includes mixed P,N ligands as metal-coordinating spacers has been recently reported by us. This heterobimetallic complex is based on two metal-containing moieties, [CpRu] (Cp= cyclopentadienyl) and [AgCl2] , and is bridged by the cagelike water-soluble monodentate phosphine 1,3,5-triaza-7phosphaadamantane (pta) in an unprecedented P,N coordination mode. More recently, the synthesis of silver coordination polymers containing pta bridging molecules in a tridentate P,N,N’ coordination mode has been reported and several examples of pta N coordination have been presented. Therefore the pta molecule could be an excellent ligand from which to obtain water-soluble Ru–Au polymers which could have interesting and useful properties for a variety of applications such as magnetism, nonlinear optics, electrocatalysis, photocatalysis, photovoltaic, template formation of ordered networks, advanced electrode materials, and conjugated coordination polymers. Herein, we describe the first water-soluble, air-stable heterobimetallic polymeric structure based on two metalcontaining moieties [CpRuCNRuCp] and [Au(CN)4] , bridged by pta in the P,N coordination mode. Interestingly, this complex display gel-like properties in water, specifically a thermally controlled volume transition. To the best of our knowledge, this is the first example of an coordination polymer network that is sensitive to its environment. The physical and chemical properties of this complex make it a promising material for industrial and biological applications, for example, smart catalysis, drug delivery, or chemical sensing. The first strategy we attempted to obtain a water soluble Ru–Au polymer was similar to that used for the synthesis of [{CpRu(pta)2(DMSO-kS)}{AgCl2}]1. [8] The complex [CpRuCl(pta)2] (1) was reacted in a straightforward manner with AuCl3 in water, EtOH, and DMSO, and in the presence of NaBF4 and NaCF3SO3. This resulted in the swift formation of a stoichiometric amount of metallic gold. A second strategy, in which the [Au(CN)4] moiety (which is very stable under a wide variety of conditions) was used, was then tested. The reaction of 1 with K[Au(CN)4] led to the partial reduction of gold together with the formation of several new species. A careful analysis of the reaction products suggested that the presence of the chloride ion in 1 could give rise to the formation of unstable gold species which finally decompose to metallic gold. To avoid the presence of the chloride ion in the reaction, the complex [RuCp(CN)(pta)2] (2) was prepared by substitution of 1 with KCN at room temperature in water (Scheme 1). Slow crystallization of a diluted H2O solution of [Ru(CNkC)Cp(pta)2] (2) in air give colorless crystals suitable for Xray diffraction. The X-ray crystal structure of complex 2 shows that it is a mononuclear complex in the solid state and is similar to 1, except that the chloride ligand has been