Architectures Of Coordination Polymers Research Articles

One Cd(II) coordination polymer based on flexible 4,4′-di(4H-1,2,4-triazole-4-yl)methyldiphenyl: Synthesis, structure and luminescent property

Under hydrothermal conditions, one Cd(II) coordination polymer (Cd-CP) has been successfully created using the flexible bis-triazole ligand and dicarboxylate ligand. In Cd-CP, one-dimensional chain structure is created by the interconnection of the adjacent cadmium ions via water bridges. To create a two-dimensional layer structure, the mutually parallel one-dimensional cadmium chains are connected further by dicarboxylate ligands. The final three-dimensional stacking structure is formed by bis-triazole ligands connecting adjacent two-dimensional layers. The theoretical computations and the experimental fluorescence characteristics are in agreement, which shed deep light on the fluorescence properties of Cd-CP. The associated findings demonstrate that the carboxylate and bis-triazole coligands can successfully modify the architectures of coordination polymers, which illustrates the feasibility of constructing functional coordination materials from bis-triazole ligands.

Phosphinic acids as building units in materials chemistry

• The properties of phosphinic acids fall between phosphonic and carboxylic acids. • Phosphinate-based ligands lead to a variety of coordination polymer architectures. • Phosphinates are used to improve the efficiency of dye-sensitized solar cells. • Phosphinate capping agents lead to unique nanoparticle properties. Diaryl and dialkyl phosphinic acids are diverse groups of ligands capable of bonding to a wide variety of metal ions. This review provides a brief overview of their synthesis methods, and summarizes various functions and binding motifs phosphinic acids can have in the area of materials chemistry. The combination of these characteristics allows for many applications in coordination polymers, modification of surfaces, synthesis of nanoparticles, and sol–gel synthesis. The possibility of tuning electronic and steric properties by two aryl/alkyl substituents directly attached to phosphorus atom translates into unique properties of materials that cannot be replicated by the utilization of analogous phosphonates or carboxylates. Recent developments in the field and perspective directions of future research are also highlighted.

Two cobalt(II) coordination polymers based on 5-i-butoxyisophthalate and dipyridyl: Syntheses, structures and efficient oxygen evolution reaction

Two new cobalt(II) clusters based 3D metal-organic frameworks (MOFs) [Co2(iBuOip)2(bpa)2(H2O)] (1) and [Co5(iBuOip)4(μ3-O)(bpp)2(DMF)(H2O)3]·2H2O (2) (iBuOip = 5-i-butoxyisophthalate, bpp = 1,3-bis(4-pyridyl)propane and bpa = 1, 2-bi(4-pyridyl)ethane), were synthesized with 5-i-butoxyisophthalate and bpp/bpa mixture ligands. Compound 1 shows a 3D network constructed from both a dinuclear cluster and mononuclear Co(II) nodes. The mixture of triangular trinuclear and rhombus tetranuclear cluster nodes linked by 5-i-butoxyisophthalate and bpp give rise to a 3D pillared-layer structure of 2. The structural and topological differences of the two complexes demonstrate that the characteristics of the N-donor auxiliary ligands play significant roles in constructing the novel architectures of coordination polymers. Electrochemical measurements reveal that 2 modified electrode is catalytically active to oxygen evolution reaction with a lower overpotential of only 340 mV at 10 mA cm-2 in neutral solution.

RETRACTED ARTICLE: Crystal Structures and Inhibiting Human Cardiac Myoma Cells Activity of Co(II) and Cu(II)-based Coordination Polymers Constructed from 4-(1H-pyrazole-4-yl)benzoic Acid and 4,4′-Bipyridine Ligands

Two new coordination polymers [Co2(L)2(4,4′-bipy)(H2O)2](DMA)2 (1, 4,4′-bipy = 4,4′-bipyridine, H2L = 4-(1H-pyrazole-4-yl)benzoic acid) and [Cu2(L)2(4,4′-bipy)](DEF)3 (2, DEF = N, N-diethylformamide), have been synthesized via solvothermal reaction of M(NO3)2·6H2O (M = Co for 1 and Cu for 2) with the pyrazolate/carboxylate ligand and the 4,4′-bipy linker. Both coordination polymer architectures in nanoscale regimes have been prepared and determined via PXRD and SEM, and the cytotoxicity of them against the human cardiac myoma cells H9C2 has been evaluated via the MTT assay with the cisplatin as the reference drug, which demonstrates better anticancer activities of the both nano architectures than those of their samples in micro regimes.

Functionalities and architectures of coordination polymers with multi-dimensionalities via transition metal–dicarboxylate ligands

Five coordination polymers based on the flexible H2dpd ligand and different metal salts have been synthesised. The configuration of the ligand and the reaction temperature have important effects on the final structures.

Straw-sheaf-like terbium-based coordination polymer architectures: microwave-assisted synthesis and their application as selective luminescent probes for heavy metal ions

Terbium-based coordination polymer architectures were successfully synthesized via a microwave heating approach and they showed highly sensitive and selective luminescence quenching to Pb2+ in aqueous solution.

Tuning cadmium coordination architectures using 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene and sulfoisophthalate

In our efforts to tune Cd(II) coordination polymer architectures, three Cd(II) coordination polymers, {[Cd3(bbtz)4(sip)2(H2O)4]·12H2O}n (1), {[Cd3(bbtz)3(sip)2(H2O)6]·4H2O}n (2) and {[Cd3(bbtz)2(sip)2(H2O)8]·4H2O}n (3), were synthesized by the slow diffusion, direct reaction and hydrothermal methods using 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene (bbtz) and sulfoisophthalate (sip). 1 shows a novel two-fold interpenetrating 5-connected 3D network, with a point symbol of 44·63·83. 2 displays an unusual 4-connected 2D network, with a point symbol of 42·63·8. 3 exhibits an unusual (3,3)-connected 2D network, with a point symbol of (83)2 and a 2D → 3D polythreaded network. The diverse structures demonstrate that the structures of coordination polymers can be tuned by the synthesis method. The luminescence and thermal stability were investigated.

Solvent-induced changes in dimensionality of praseodymium coordination polymers with diphenylphosphorylvalerate ligand

Architectures of coordination polymers resulting from the reaction of diphenylphosphorylvaleric acid (1) with Pr(NO3)3·6H2O in the presence of a base can be controlled by the solvent. While in methanolic solution a two-dimensional network Pr2(1–H)3(NO3)3 (1m) with a 1:1.5 metal-to-ligand ratio was formed, the aqueous media induced the formation of a three-dimensional framework Pr(1–H)2(NO3) (1w) with a 1:2 metal-to-ligand ratio. The compounds were studied by single crystal X-ray diffraction, IR spectroscopy, ESI-TOF mass spectrometry, and thermal analysis TG/DSC techniques.

Tuning Cobalt Coordination Architectures by Bis(1,2,4-triazol-1-ylmethyl)benzene Position Isomers and 5-Nitroisophthalate

In our effect to tune the Co(II) coordination polymer architectures, three position isomers 1,2-, 1,3-, 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene and rigid 5-nitroisophthalate were used to assembly Co(II) coordination polymers [Co(obtz)(NO2-1,3-bdc)]n (1), [Co(mbtz)(NO2-1,3-bdc)(CH3OH)]n (2), and [Co(bbtz)(NO2-1,3-bdc)(H2O)]n (3). 1 is comprised of undulated two-dimensional (2D) (4,4) networks. Two identical undulated layers are parallel interpenetrated to each other to give a (2D → 2D) polycatenated 2D network. The adjacent polycatenated 2D layers parallel polythreaded to form a unique 3D network. 1 is an unusual 2D → 3D polythreaded framework based on the polycatenated 2D layers. 2 shows the double-layer structure through the hydrogen bonds and π···π stacking interactions based on the undulated 2D (4,4) network. A 3D supramolecular network is constructed through the π···π stacking interactions interdouble layers. 3 exhibits a 3-fold interpenetrating 4-connected 65·8-CdSO4 3D network. The powder X-ray dif...

Coordination-Induced Assembly of Coordination Polymer Submicrospheres: Promising Antibacterial and in Vitro Anticancer Activities

Spheres-like coordination polymer architectures in submicro regimes have been synthesized from the hydrothermal reaction of transition metal ions and 3,5-bis(pyridin-3-ylmethylamino)benzoic acid (L1). The size of the final coordination polymer was dependent on the concentrations of reactants. Scanning electron microscopy studies monitored at numerous stages of growth reveal that coordination-induced morphology changes from uncoordinated flowerlike ligands to sphere-like coordination polymer particles. Moreover, variations of luminescent and antibacterial profiles are associated with coordination environments or the size of as-obtained coordination polymer samples. In addition, the newly synthesized Cu-based polymer particles may act as novel metal-based anticancer drugs in the future because of their potent in vitro anticancer activities against three chosen cancer lines MCF-7, HeLa, and NCI-H446.

Hyperbranched microspheres formed by an EDTA-based coordination polymer with ternary architectures assembled by ultrathin nanoribbons and their tricolor luminescent properties

Here we report a novel structure of hierarchical coordination polymers with hyperbranched microspheres. The microspheres were formed by the automatic piling of ultrathin nanoribbons with a thickness of 3.5 ± 0.1 nm, which resulted from the prior self-assembly of the molecules in a ternary architecture. Briefly, the ultrathin nanoribbons of the lanthanide–EDTA coordination polymers were prepared via an Ostwald ripening process, by a simple hydrothermal treatment in an aqueous mixture of lanthanide cations and EDTA-2Na ligands. To satisfy the requirement of a low surface/interface energy, these ultrathin nanoribbons were then self-assembled into multi-layer nanoribbons, followed by the formation of hyperbranched microspheres. Finally, tricolor (red, green and blue, known as RGB) fluorescent hyperbranched microspheres were also prepared by doping with Eu3+, Tb3+ and Zn2+ as luminescent centers, respectively. Our work shows a simple method to fabricate complex structures of coordination polymers and may inspire further studies on hierarchical architectures of coordination polymers.

Coordination Polymers and Metal Organic Frameworks Derived from 1,2,4-Triazole Amino Acid Linkers

The perceptible appearance of biomolecules as prospective building blocks in the architecture of coordination polymers (CPs) and metal-organic frameworks (MOFs) are redolent of their inclusion in the synthon/tecton library of reticular chemistry. In this frame, for the first time a synthetic strategy has been established for amine derivatization in amino acids into 1,2,4-triazoles. A set of novel 1,2,4-triazole derivatized amino acids were introduced as superlative precursors in the design of 1D coordination polymers, 2D chiral helicates and 3D metal-organic frameworks. Applications associated with these compounds are diverse and include gas adsorption-porosity partitioning, soft sacrificial matrix for morphology and phase selective cadmium oxide synthesis, FeII spin crossover materials, zinc-b-lactamases inhibitors, logistics for generation of chiral/non-centrosymmetric networks; and thus led to a foundation of a new family of functional CPs and MOFs that are reviewed in this invited contribution.

Syntheses, structures and magnetic properties of cobalt(ii) and nickel(ii) complexes based on 5-methylisophthalate and different dipyridyl-containing ligands

Four new CoII and NiII coordination polymers, {[Co(mip)(bpa)]}n (1), {[Co(mip)(bpp)]}n (2), {[Ni(mip)(bpa)]}n (3), {[Ni(mip)(bpp)(H2O)]}n (4) (H2mip = 5-methylisophthalic acid, bpa = 1,2-bi(4-pyridyl)-ethane, bpp = 1,3-di(4-pyridyl)-propane), were prepared viahydrothermal reactions based on H2mip and two bridging dipyridyl ligands. Their crystal structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses and IR spectra. Complexes 1 and 3 are structurally similar with an infinite bilayer spanning two different directions except for the different central metal ions. The structure of 2 shows a 1D polymeric ribbon due to the GG conformation of the bpp ligand, which is further extended to a 2D supramolecular layer by the C–H⋯π interactions. Complex 4 possesses a two-fold interpenetrating (3,5)-connected hms network constructed from supramolecular interactions. The structural and topological differences of the four complexes demonstrate that the central metal ions and the characteristics of the N-donor auxiliary ligands play significant roles in constructing the novel architectures of coordination polymers. The magnetic properties of 1–4 were studied in the 2–300 K region at 2000 G.

Organic-Acid Effect on the Structures of a Series of Lead(II) Complexes

An investigation into the dependence of coordination polymer architectures on organic-acid ligands is reported on the basis of the reaction of Pb(NO3)2 and eight structurally related organic-acid ligands in the presence or absence of N-donor chelating ligands. Eight novel lead(II)-organic architectures, [Pb(adip)(dpdp)]2 1, [Pb(glu)(dpdp)] 2, [Pb(suc)(dpdp)] 3, [Pb(fum)(dpdp)] . H2O 4, [Pb2(oba)(dpdp)2] . 2(dpdp).2(NO3).2H2O 5, [Pb2(1,4-bdc)2(dpdp)2] . H2O 6, [Pb(dpdc)(dpdp)] 7, and [Pb(1,3-bdc)(dpdp)] . H2O 8, where dpdp = dipyrido[3,2-a:2',3'-c]-phenazine, H2adip = adipic acid, H2glu = glutaric acid, H2suc = succinic acid, H2fum = fumaric acid, H2oba = 4,4'-oxybis(benzoic acid), 1,4-H2bdc = benzene-1,4-dicarboxylic acid, H2dpdc = 2,2'-diphenyldicarboxylic acid, and 1,3-H2bdc = benzene-1,3-dicarboxylic acid, were successfully synthesized under hydrothermal conditions through varying the organic-acid linkers and structurally characterized by X-ray crystallography. Compounds 1-8 crystallize in the presence of organic-acid linkers as well as secondary N-donor chelating ligands. Diverse structures were observed for these complexes. 1 and 5 have dinuclear structures, which are further stacked via strong pi-pi interactions to form 2D layers. 2-3 and 6-8 feature chain structures, which are connected by strong pi-pi interactions to result in 2D and 3D supramolecular architectures. Compound 4 contains 2D layers, which are further extended to a 3D structure by pi-pi interactions. A systematic structural comparison of these 8 complexes indicates that the organic-acid structures have essential roles in the framework formation of the Pb(II) complexes.

Syntheses, crystal structures and magnetic properties of three copper(II) coordination polymers with the flexible ligand 1,2-bis(1,2,4-triazol-1-yl)ethane or 1,2-bis(imidazol-1-yl)ethane

In order to investigate the influence of the flexibility of the ligand molecules and the coordination counter anions on the architecture of coordination polymers, three new copper(II) coordination polymers [Cu(bte) 2(dca) 2] n (1), [Cu(bte)(NCS) 2] n (2) and [Cu(bim)(NCS) 2] n (3) were synthesized using the flexible five-membered heterocyclic ligands 1,2-bis(1,2,4-triazol-1-yl)ethane (bte), 1,2-bis(imidazol-1-yl)ethane (bim) and the anion ligands dicyanamide (dca) and thiocyanate. They are characterized by elemental analysis, IR, thermogravimetric analysis and X-ray diffraction analysis. The X-ray diffraction analysis shows that complexes 1, 2 and 3 form the one-dimensional double-stranded chain, linear chain and zigzag chain structures, respectively. The magnetic properties for complexes 1, 2 and 3 have also been studied.

Synthesis and Characterisation of Coordination Polymers of CuII and ZnII with 1,3‐Bis(1,2,3,4‐tetrazol‐2‐yl)propane − Rotational Freedom of the Donor Group Favours Structural Diversification

AbstractThe novel bidentate ligand 1,3‐bis(1,2,3,4‐tetrazol‐2‐yl)propane (pbtz), which possesses a flexible spacer, was synthesised in order to investigate the influence of the flexibility of ligand molecules on the architecture of coordination polymers. For that purpose the reactions between pbtz and M(ClO4)2·6H2O salts (M = CuII and ZnII) were performed. The complexes [{Cu(pbtz)3}(ClO4)2]∞ and [{Zn(pbtz)3}(ClO4)2·2EtOH]∞ were characterised by IR and UV/Vis spectroscopy and their crystal structures were determined by single‐crystal X‐ray diffraction measurements. In both compounds the pbtz ligand molecules act as N4,N4′ connectors bridging the central atoms, and the 2‐substituted tetrazole rings coordinate in a monodentate fashion to the central atoms forming M(tetrazole)6 cores. [{Cu(pbtz)3}(ClO4)2]∞ was isolated as a 1D coordination polymer. The copper(II) ions are triply bridged by ligand molecules, leading to the formation of infinite 1D chains. A highly unusual manner of bridging, with the tethering of two neighbouring central atoms by the same kind of ligand molecules, although possessing different conformations, is observed. In [{Zn(pbtz)3}(ClO4)2·2EtOH]∞ the six‐coordinate zinc(II) ions, which are bridged by single ligand molecules, serve as topological nodes, leading to the formation of a 3D α‐polonium‐type network. The crystal structure of the ZnII complex contains only one such net solvated by ethanol molecules. A conformational analysis of the ligand molecules in both compounds demonstrates that the flexibility of the pbtz and the ability of the tetrazole rings in particular to adopt various, relative orientations is responsible for the diversity of the architectures of the obtained complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

2D and 1D Coordination Polymers with the Ability for Inclusion of Guest Molecules: Nitrobenzene, Benzene, Alkoxysilanes

The complexation reactions of the electron rich, linear and bi-functional ligand, 9,10-bis(4-pyridyl)anthracene, with metal salts Cd(NO3)2, CdI2, CoI2 and CuI in the presence of guest molecules nitrobenzene, benzene and alkoxysilanes were studied. The single crystal analyses of the complexes reveal that an electron deficient guest molecule such as nitrobenzene consistently templated the open two-dimensional network with grid dimensions of ca. 15 × 15A. On the other hand the presence of benzene or alkoxysilane templated1D-zigzag chains and/or 2D-grid layers. The crystal structures revealthe importance of host–guest interactions in tailoring the network architectures ofcoordination polymers.