Showing papers on "Coordination polymer published in 2013"
TL;DR: A multifunctional Cu(I) coordination polymer constructed from helical chains showed unusual mechanochromic, sensing of nitrobenzene and photocatalytic properties on degradation of organic dyes.
271 citations
TL;DR: A luminescent two-dimensional (2D) coordination polymer is demonstrated to be a selective sensing material for the straightforward detection of nitrobenzene via a redox fluorescence quenching mechanism.
Abstract: A luminescent two-dimensional (2D) coordination polymer is demonstrated to be a selective sensing material for the straightforward detection of nitrobenzene via a redox fluorescence quenching mechanism.
230 citations
TL;DR: Two isomersic two-dimensional copper(I) coordination polymer materials based on an in situ generated 5-(3-pyridyl)tetrazole ligand show similar layer structures but distinct photoluminescent and photocatalytic properties, which present an interesting comparative study on the structure-property correlation between isomeric materials.
Abstract: Two isomeric two-dimensional copper(I) coordination polymer materials based on an in situ generated 5-(3-pyridyl)tetrazole ligand show similar layer structures but distinct photoluminescent and photocatalytic properties, which present an interesting comparative study on the structure–property correlation between isomeric materials.
226 citations
TL;DR: The potential of 1a for nitro explosive sensing is studied through luminescence quenching experiments, which show that 1a is a potential luminescent sensory material for nitroglycerine explosives.
Abstract: A microporous metal–organic framework (MOF) Eu3(MFDA)4(NO3)(DMF)3 (1, H2MFDA = 9,9-dimethylfluorene-2,7-dicarboxylic acid) has been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction. 1 is a three-dimensional coordination polymer with pcu type rod-packing structure, through which 1D rhombic channels penetrate. The solvent-free form 1a could be obtained by direct heating of 1. Both 1 and 1a exhibit high intensity red light emissions with high quantum yields and long luminescence lifetimes when excited at 336 nm at ambient temperature. The potential of 1a for nitro explosive sensing is studied through luminescence quenching experiments, which show that 1a is a potential luminescent sensory material for nitro explosives.
214 citations
TL;DR: In this paper, a new porous coordination polymer, ([La(BTB)H2O]·solvent (1⊃guest)), is synthesized. But this polymer exhibits high CH4 separation capability toward CO2 and C2 hydrocarbons at 273 K.
Abstract: A new porous coordination polymer, ([La(BTB)H2O]·solvent (1⊃guest)), is synthesized. Gas adsorption, ideal adsorbed solution theory (IAST) and breakthrough experiments of it exhibits high CH4 separation capability toward CO2 and C2 hydrocarbons at 273 K. In addition, this also shows good water and chemical stability, in particular, it is stable at pH = 14 at 100 °C, which is unprecedented for carboxylate-based porous coordination polymers. Furthermore, the effective adsorption site for separation is revealed by using an in situ diffuse reflectance IR fourier transform (DRIFT) spectra study.
176 citations
TL;DR: The Mn-LCP electrode exhibits an irreversible high capacity in the first discharge process and a reversible lithium storage capacity of up to about 390 mA h/g from the fourth cycle, which might provide a new method for finding new electrode materials in lithium-ion batteries.
Abstract: Manganese-based layered coordination polymer ([Mn(tfbdc)(4,4'-bpy)(H2O)2], Mn-LCP) with microporous structure was synthesized by reaction of 2,3,5,6-tetrafluoroterephthalatic acid(H2tfbdc) and 4,4'-bipyridine(4,4'-bpy) with manganese(II) acetate tetrahydrate in water solution. Mn-LCP was characterized by elemental analysis, IR spectra, thermogravimetric analysis, X-ray single-crystal structure analysis, and powder X-ray diffraction. Magnetic susceptibility data from 300 to 1.8K show that there is a weak antiferromagnetic exchange between Mn(II) ions in Mn-LCP. As anode material, the Mn-LCP electrode exhibits an irreversible high capacity in the first discharge process and a reversible lithium storage capacity of up to about 390 mA h/g from the fourth cycle. It might provide a new method for finding new electrode materials in lithium-ion batteries.
175 citations
TL;DR: The use of macrocyclic complexes as building blocks in a selection of supramolecular systems is discussed with emphasis on the properties, such as enhanced stabilities, that cyclic ligands and their complexes may impart on the resulting assemblies.
Abstract: In this tutorial review the use of macrocyclic complexes as building blocks in a selection of supramolecular systems is discussed with emphasis on the properties, such as enhanced stabilities, that cyclic ligands and their complexes may impart on the resulting assemblies. An aim of the review is to exemplify the versatility of macrocyclic ligand complexes for use as components in a range of both discrete and polymeric systems. The use of macrocyclic systems for controlling CuI aggregation, as scaffolds for metal-cluster formation, as the cyclic components in interlocked catenane and rotaxane structures, for constructing assemblies based on macrocycle exo-coordination, for forming columnar stacks, as well as their roles as both structural and redox centres in a range of coordination polymer types are all presented.
169 citations
TL;DR: The scalable, bottom-up synthesis of ultrathin coordination polymer nanosheets via surfactant-mediated synthesis and subsequent exfoliation is reported on, revealing a high level of order on both the atomic and mesoscale, suggesting fairly strong interactions along the organic-inorganic hybrid interface.
Abstract: Low-dimensional nanostructures offer a host of intriguing properties which are distinct from those of the bulk material, owing to size-confinement effects and amplified surface areas. Here, we report on the scalable, bottom-up synthesis of ultrathin coordination polymer nanosheets via surfactant-mediated synthesis and subsequent exfoliation. Layers of a two-dimensional (2D) zinc coordination polymer are self-assembled in the interlamellar space of a reverse microemulsion mesophase into stacks of nanosheets interleaved with cethyltrimethylammonium bromide (CTAB) at regular intervals, thus giving rise to a lamellar hybrid mesostructure with a lattice period of ∼8 nm and an underlying highly crystalline substructure. The basic structural motif is composed of 2D acetato–benzimidazolato–zinc layers of tetrahedrally coordinated zinc joined together by anionic acetate and benzimidazolate ligands. The hierarchical structure was studied by PXRD, TEM, EDX, EELS, AFM, and solid-state NMR spectroscopy, revealing a hi...
162 citations
TL;DR: By fine tuning these systems through metal ion and ligand selection and by directing self-assembly with external stimuli the rational synthesis of practical systems can be envisaged.
Abstract: Coordination Polymer Gels (CPGs) constitute a subset of solid-like metal ion and bridging organic ligand structures (similar to metal-organic frameworks) that form multi-dimensional networks through a trapped solvent as a result of non-covalent interactions. While physical properties of these gels are similar to conventional high molecular weight organic polymer gels, coordination polymer gel systems are often fully reversible and can be assembled and disassembled in the presence of additional energy (heat, sonication, shaking) to give a solution of solvated gelators. Compared to gels resulting from purely organic self-assembled low molecular weight gelators, metal ions incorporated into the fibrilar networks spanning the bulk solvent can impart CPGs with added functionalities. The solid/liquid nature of the gels allows for species to migrate through the gel system and interact with metals, ligands, and the solvent. Chemosensing, catalysis, fluorescence, and drug-delivery applications are some of the many potential uses for these dynamic systems, taking advantage of the metal ion's coordination, the organic polydentate ligand's orientation and functionality, or a combination of these properties. By fine tuning these systems through metal ion and ligand selection and by directing self-assembly with external stimuli the rational synthesis of practical systems can be envisaged.
161 citations
TL;DR: The most recent advances in CPP synthesis to their use as smart drug delivery systems, bioimaging probes or a combination of both are outlined.
156 citations
TL;DR: A strategy that relies on 'ordered crosslinks' to produce polymeric materials that exhibit a crystalline arrangement that is stable to thermal and solvent treatments, as demonstrated by X-ray powder diffraction and transmission electron microscopy.
Abstract: Chain alignment can significantly influence the macroscopic properties of a polymeric material, but no general and versatile methodology has yet been reported to obtain highly ordered crystalline packing of polymer chains, with high stability. Here, we disclose a strategy that relies on 'ordered crosslinks' to produce polymeric materials that exhibit a crystalline arrangement. Divinyl crosslinkers (2,5-divinyl-terephthalate) were first embedded, as substitutional ligands, into the structure of a porous coordination polymer (PCP), [Cu(terephthalate)triethylenediamine0.5]n. A representative vinyl monomer, styrene, was subsequently polymerized inside the channels of the host PCP. The polystyrene chains that form within the PCP channels also crosslink with the divinyl species. This bridges together the polymer chains of adjacent channels and ensures that, on selective removal of the PCP, the polymer chains remain aligned. Indeed, the resulting material exhibits long-range order and is stable to thermal and solvent treatments, as demonstrated by X-ray powder diffraction and transmission electron microscopy.
TL;DR: A coordination polymer is fully exfoliated by solvent-assisted interaction only and shows a layered structure with weak layer-to-layer interactions and cavities with the ability to locate several solvents in an unselective way.
Abstract: A coordination polymer is fully exfoliated by solvent-assisted interaction only. The soft-delamination process results from the structure of the starting material, which shows a layered structure with weak layer-to-layer interactions and cavities with the ability to locate several solvents in an unselective way. These results represent a significant step forward towards the production of structurally designed one-molecule thick 2D materials with tailored physico-chemical properties.
TL;DR: This method was successfully applied to determine the levels of Tc in milk, which is the first application of coordination polymer as a fluorescent sensor in real sample and could be extended to the preparation of other lanthanide coordination polymer-based fluorescent probes for applications in biosensing, imaging, drug delivery, and so on.
TL;DR: A new type of coordination polymer sphere prepared by combining 1,1'-(1,4-butanediyl)bis(imidazole) (bbi) and ferrous ions has been demonstrated as a targeted delivery system for in situ encapsulating anticancer drugs and shows sustainable drug release for several days due to their superior stability.
Abstract: A new type of coordination polymer sphere prepared by combining 1,1′-(1,4-butanediyl)bis(imidazole) (bbi) and ferrous ions has been demonstrated as a targeted delivery system for in situ encapsulating anticancer drugs. These stable coordination polymer spheres can be fabricated simply by a deposition method. Drugs, doxorubicin hydrochloride (DOX·HCl) for example, can be easily in situ encapsulated by simply mixing the drug with bbi ligand through the deposition method and results in a high drug loading efficiency up to 98% and a drug loading content of nearly 40%, which is remarkably high for not only metal–organic but also other materials. A noticeable feature of the drug loaded coordination polymer spheres is that they show sustainable drug release for several days due to their superior stability, and are sensitive to external pH owing to the coordination bonds. The drug can be released faster in mild acidic conditions in comparison to physiological acidity. By conjugating folic acid to the surface of the coordination polymer spheres, the vehicles can be taken up selectively by cancer cells through cell surface receptor-mediated mechanisms. Cell viability experiments with HeLla cells demonstrated the low toxicity of the delivery vehicles and the good anticancer efficacy of the drug-loaded coordination polymer spheres.
TL;DR: A spin-crossover Fe(II) coordination polymer with no permanent channels that selectively sorbs CO2 over N2 and modifies the spin transition, producing a 9 K increase in T1/2.
Abstract: We present a spin-crossover Fe(II) coordination polymer with no permanent channels that selectively sorbs CO2 over N2. The one-dimensional chains display internal voids of ∼9 A diameter, each being capable to accept one molecule of CO2 at 1 bar and 273 K. X-ray diffraction provides direct structural evidence of the location of the gas molecules and reveals the formation of O═C═O(δ(-))···π interactions. This physisorption modifies the spin transition, producing a 9 K increase in T1/2.
TL;DR: A new concept for synthesizing monodispersed coordination polymer (CP) nanoparticles is established by utilizing a chelating agent that is coordinated to the metal ions, the subsequent coordination process between metal ions and ligands is controllable.
Abstract: Under control: A new concept for synthesizing monodispersed coordination polymer (CP) nanoparticles is established. By utilizing a chelating agent that is coordinated to the metal ions, the subsequent coordination process between metal ions and ligands is controllable (see figure). The obtained nanocubes with uniform sizes can be self-assembled into periodically ordered arrangements. This phenomenon is useful for sensing applications, such as those with responsive photonic crystals.
TL;DR: A perspective on utilising this pH-responsive system in in vitro cell assays and in vivo tumour assays as well as further possibilities for clinical applications are provided.
TL;DR: NMR studies revealed a hydrogen-bond interaction between the framework and methanol, which enables the modulation of proton conductivity within the framework, demonstrating the dual functionality of the framework.
Abstract: We report the synthesis and characterization of a coordination polymer that exhibits both intrinsic proton conductivity and gas adsorption. The coordination polymer, consisting of zinc ions, benzimidazole, and orthophosphate, exhibits a degree of flexibility in that it adopts different structures before and after dehydration. The dehydrated form shows higher intrinsic proton conductivity than the original form, reaching as high as 1.3 × 10–3 S cm–1 at 120 °C. We found that the rearranged conduction path and liquid-like behavior of benzimidazole molecules in the channel of the framework afforded the high proton conductivity. Of the two forms of the framework, only the dehydrated form is porous to methanol and demonstrates guest-accessible space in the structure. The proton conductivity of the dehydrated form increases by 24 times as a result of the in situ adsorption of methanol molecules, demonstrating the dual functionality of the framework. NMR studies revealed a hydrogen-bond interaction between the fr...
TL;DR: In this article, the octadentate ligand tetrakis[(3,5-dicarboxyphenoxy)methyl] methane (H8L), a rare (4,8)-scu type microporous coordination polymer, was synthesized and structurally characterized.
Abstract: By using the octadentate ligand tetrakis[(3,5-dicarboxyphenoxy)methyl] methane (H8L), a rare (4,8)-scu type microporous coordination polymer, [In2L][NH2(CH3)2]2·(DMF)4(H2O)16, was synthesized and structurally characterized. The compound possesses an anionic three-dimensional open framework and exhibits permanent porosity with selective gas adsorption of CO2 over CH4. It exhibited strong fluorescence emission upon excitation at RT, and a selective, efficient emission quenching response towards nitroaromatic explosives.
TL;DR: In this paper, the synthesis, characterization, and properties of a multifunctional oxalate dianion with two metal ions in terms of their size, charge, and electronic configuration were reported.
Abstract: We report synthesis, characterization, and properties of a multifunctional oxalate framework, {KDy(C2O4)2(H2O)4}n (1) (C2O42– = oxalate dianion) composed of two absolutely different metal ions in terms of their size, charge, and electronic configuration. Dehydrated framework (1′) exhibits permanent porosity and interesting solvent (H2O, MeOH, CH3CN, and EtOH) vapor sorption characteristics based on specific interactions with unsaturated alkali metal sites on the pore surface. Compound 1 shows solvent responsive bimodal magnetic and luminescence properties related to the DyIII center. Compound 1 exhibits reversible ferromagnetic to antiferromagnetric phase transition upon dehydration and rehydration, hitherto unknown for any lanthanide based coordination polymer or metal–organic frameworks. Both the compounds 1 and 1′ exhibit slow magnetic relaxation with very high anisotropic barrier (417 ± 9 K for 1 and 418 ± 7 K for 1′) which has been ascribed to the single ion magnetic anisotropy of the DyIII centers. ...
TL;DR: The design and synthesis of a responsive lanthanide coordination polymer (LCP) for hydrogen sulfide (H2S) is reported, utilizing self-assembling of biomolecule nucleotide with luminescent terbium ion (Tb(3+)) and sensitizing silver ion (Ag(+)) in aqueous solution.
Abstract: Metal organic coordination polymers have received great attention because of their flexible compositions and architecture. Here, we report the design and synthesis of a responsive lanthanide coordination polymer (LCP) for hydrogen sulfide (H2S), utilizing self-assembling of biomolecule nucleotide with luminescent terbium ion (Tb3+) and sensitizing silver ion (Ag+) in aqueous solution. LCP is highly fluorescent due to the inclusion of Ag+ ions, which sensitized the fluorescence of Tb3+ ions. H2S can strongly quench the fluorescence of LCP through its high affinity for Ag+ ions. Such configurated LCP material from initial building blocks showed high sensitivity and selectivity for H2S and was applied to the determination of H2S in human serum. LCP with Tb3+ ions also has a long fluorescence lifetime, which allows for time-resolved fluorescence assays, possessing particular advantages to probing H2S in biological systems with autofluorescence.
TL;DR: In this article, a two-dimensional morphology characterizes the nanoflakes obtained in the bottom-up synthesis of a single-crystalline coordination polymer, Ni(HO)[Ni(CN)]×x HO.
Abstract: A two-dimensional morphology characterizes the nanoflakes that are obtained in the bottom-up synthesis of a single-crystalline coordination polymer, Ni(HO)[Ni(CN)]×x HO. The 10 nm-thick nanoflakes are well-dispersed in solution and have a very high accessible surface area (240 m g). Thermal treatment leads to nanoporous NiO with retention of the original flake morphology.
TL;DR: These studies demonstrate that some of these compounds exhibit very promising optical properties and that there are two ways of modulating the luminescent properties: playing with the composition of the heterohexanuclear entities orPlaying with the relative ratio between two different hexanuclear entity enables the independent tuning of luminescence intensity and color.
Abstract: Reactions in solvothermal conditions between hexanuclear rare earth complexes and H2bdc, where H2bdc symbolizes terephthalic acid, lead to a family of monodimensional coordination polymers in which hexanuclear complexes act as metallic nodes. The hexanuclear cores can be either homometallic with general chemical formula [Ln6O(OH)8(NO3)6](2+) (Ln = Pr-Lu plus Y) or heterometallic with general chemical formula [Ln(6x)Ln'(6-6x)O(OH)8(NO3)6](2+) (Ln and Ln' = Pr-Lu plus Y). Whatever the hexanuclear entity is, the resulting coordination polymer is iso-structural to [Y6O(OH)8(NO3)2(bdc)(Hbdc)2·2NO3·H2bdc]∞, a coordination polymer that we have previously reported. The random distribution of the lanthanide ions over the six metallic sites of the hexanuclear entities is demonstrated by (89)Y solid state NMR, X-ray diffraction (XRD), and luminescent measurements. The luminescent and colorimetric properties of selected compounds that belong to this family have been studied. These studies demonstrate that some of these compounds exhibit very promising optical properties and that there are two ways of modulating the luminescent properties: (i) playing with the composition of the heterohexanuclear entities or (ii) playing with the relative ratio between two different hexanuclear entities. This enables the independent tuning of luminescence intensity and color.
TL;DR: The cytotoxic effect of the compounds showed that the polymeric Cu(II) complex exhibited excellent anticancer activity against Hep G2, and A431 cells which is six to ten times better than that of well-known commercial anticancer drug, cisplatin.
TL;DR: The dissimilar growth behavior, that is, growth in an isotropic or anisotropic fashion, is found to be dependent on the size of the metal ions involved within the CPs.
Abstract: The ability to fabricate multicompositional hybrid materials in a precise and controlled manner is one of the primary goals of modern materials science research. In addition, an understanding of the phenomena associated with the systematic growth of one material on another can facilitate the evolution of multifunctional hybrid materials. Here, we demonstrate precise manipulation of the isotropic and/or anisotropic nanoscale growth of various coordination polymers (CPs) to obtain heterocompositional hybrid coordination polymer particles. Chemical composition analyses conducted at every growth step reveal the formation of accurately assembled hybrid nanoscale CPs, and microscopy images are used to examine the morphology of the particles and visualize the hybrid structures. The dissimilar growth behavior, that is, growth in an isotropic or anisotropic fashion, is found to be dependent on the size of the metal ions involved within the CPs.
TL;DR: A novel method for the sensing of acetylcholinesterase (AChE) activity and inhibitor screening based on the formation of metal coordination polymer has been developed and could be used for the sensitive detection of other hydrolytic enzyme activities with properly selected substrates and for the screening of potential inhibitor drugs.
Abstract: A novel method for the sensing of acetylcholinesterase (AChE) activity and inhibitor screening based on the formation of metal coordination polymer has been developed. Acetylthiocholine (ATCh) was selected as the substrate. In the presence of AChE, ATCh was hydrolyzed to thiocholine and acetate. Thiocholine interacted with Ag(I) to form a metal coordination polymer. A positively charged perylene probe (probe 1) was employed. The fluorescence of probe 1 was very efficiently quenched by a polyanion [PVS, poly(vinyl sulfonate)]. In the presence of acetylcholinesterase, the positively charged metal coordination polymer newly formed in situ would interact with PVS, probe 1 monomer molecules were released, and a turn on fluorescence signal was detected. The assay is highly sensitive, a limit of detection of 0.04 mU/mL AChE was obtained. The assay is also highly selective, a number of potential interference proteins (enzymes) were tested, and none of them show noticeable interference. Sensing of AChE inhibitor was also demonstrated. Our assay is fairly simple and inexpensive. We envision that it could be used for the sensitive detection of other hydrolytic enzyme activities with properly selected substrates and for the screening of potential inhibitor drugs.
TL;DR: Across this series, the π···π interactions have a dramatic impact on the self-assembly of these entanglement structures, in either case it can exert an important structure-directing role.
Abstract: Hydrothermal synthesis has afforded five divalent zinc coordination polymers containing 4-(4-carboxyphenyl)-2,2′:6′,2′′-terpyridine (HL1) or its isomer 4-(4-carboxyphenyl)-2,2′:4′,4′′-terpyridine (HL2), with or without the addition of auxiliary ligands, 1,3,5-benzenetricarboxylic acid (H3btc) and 1,4-benzenedicarboxylic acid (H2bdc) Their structures have been characterized by single crystal X-ray analyses and further characterized by infrared spectra, elemental analyses, powder X-ray diffraction, thermogravimetric analyses and photoluminescent spectra Across this series, the π⋯π interactions have a dramatic impact on the self-assembly of these entanglement structures, in either case it can exert an important structure-directing role In addition, the disposition of pyridine nitrogen atoms in ligands also plays a large role in structure direction in this system Complex 1 is a 2D + 2D→3D inclined polycatenated coordination polymer based on the resulting array of 2D (6,3) layers constructed by 1D→2D π⋯π directed self-assembly Complex 2 is assembled into a 3D framework by means of 1D + 1D→3D mutual interdigitation based on 1D→1D self-assembly driven by π⋯π stacking interactions Complex 3 shows a 2D + 2D→3D interdigital network involving 2D + 2D→2D parallel interpenetrated and 2D + 2D→2D interdigital (4,4) layer motifs Complex 4 displays a 2D + 2D→3D polythreaded framework based on a 2D (4,4) network comprised of alternating rings and rods Complex 5 is a (3,4)-connected 3D framework with topology (482103)(482) In comparison with covalently connected entanglements, such π⋯π directing self-assembly of entanglements are far less explored, especially, polycatenane based on 1D chain motifs and polythread based on 2D layer motifs are rarely reported Furthermore, the luminescent properties of complexes 1–5 at room temperature have also been studied in detail herein
TL;DR: In this paper, the same solution was allowed to stand for at least several days, 2 is replaced by blocks comprising a supramolecular isomer of 2, dimeric 1, with formula {Cd[S2CN(iPr)CH2CH2OH]2}2·2H2O·2MeCN, and two ligands coordinating μ2,κ2 as in 2 and the other two purely κ2-chelating.
Abstract: Needles of [{Cd[S2CN(iPr)CH2CH2OH]2}3·MeCN]∞ (2) were harvested from a dry acetonitrile solution of Cd[S2CN(iPr)CH2CH2OH]2 after one or two days and proved to be a coordination polymer in which all dithiocarbamate ligands are μ2,κ2-tridentate, bridging two cadmium atoms and simultaneously chelating one of these. If the same solution was allowed to stand for at least several days, 2 is replaced by blocks comprising a supramolecular isomer of 2, dimeric 1, with formula {Cd[S2CN(iPr)CH2CH2OH]2}2·2H2O·2MeCN, and two ligands coordinating μ2,κ2 as in 2 and the other two purely κ2-chelating. The time dependency correlates with the pivotal role of water in driving the conversion of “chain” 2 to “ball” 1; crystals of 2 could not be isolated from “wet” acetonitrile. When each of 1 and 2 are dissolved in solution, they exhibit comparable spectroscopic attributes (1H, 13C, and 113Cd NMR and UV/vis), indicating the solution structures are the same. Both 1 and 2 are luminescent in the solid state with 1 being significa...
TL;DR: A threefold interpenetrated pillared-layer porous coordination polymer with pcu topology, [Zn(2)(bpeb)(obc)(2)]·5H(2)O (1), which comprised an unusual isomers of the well-known paddle-wheel building block and the trans-trans-trans isomer of the bpeb pillar ligand.
Abstract: Solvothermal reaction of Zn(NO(3))(2)·4H(2)O, 1,4-bis[2-(4-pyridyl)ethenyl]benzene (bpeb) and 4,4'-oxybisbenzoic acid (H(2)obc) in the presence of dimethylacetamide (DMA) as one of the solvents yielded a threefold interpenetrated pillared-layer porous coordination polymer with pcu topology, [Zn(2)(bpeb)(obc)(2)]·5H(2)O (1), which comprised an unusual isomer of the well-known paddle-wheel building block and the trans-trans-trans isomer of the bpeb pillar ligand. When dimethylformamide (DMF) was used instead of DMA, a supramolecular isomer [Zn(2)(bpeb)(obc)(2)]·2DMF·H(2)O (2), with the trans-cis-trans isomer of the bpeb ligand with a slightly different variation of the paddle-wheel repeating unit, was isolated. In MeOH, single crystals of 2 were transformed by solvent exchange in a single-crystal-to-single-crystal (SCSC) manner to yield [Zn(2)(bpeb)(obc)(2)]·2H(2)O (3), which is a polymorph of 1. SCSC conversion of 3 to 2 was achieved by soaking 3 in DMF. Compounds 1 and 2 as well as 2 and 3 are supramolecular isomers.
TL;DR: A new 2D Gd(III)-based coordination polymer has close to the highest cryogenic magnetocaloric effect of any MOF reported so far, and its structural features and magnetic properties are revealed.
Abstract: A new 2D Gd(III)-based coordination polymer has close to the highest cryogenic magnetocaloric effect of any MOF reported so far. The experimental results reveal its structural features and magnetic properties.