Supramolecular Network Structure Research Articles

Two Zn(II) complexes based on bis(benzimidazole) and different dicarboxylate anions: synthesis, structures, and fluorescent properties

Two new zinc(II) complexes, [Zn2(PBM)2(terephthalate)(formate)2] (1) and {[Zn(PBM)(fumarate)]∙H2O}n (2), were synthesized using 1,3-bis(1H-benzo[d]imidazol-2-yl)propane (PBM) and two different dicarboxylic acids under solvothermal conditions. Complexes 1 and 2 have been characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction analysis. The structural analysis showed that 1 was a binuclear structure and then formed a 3D supramolecular network structure through hydrogen bond and π-π conjugation, while 2 was a one-dimensional coordination polymer. In 1 and 2, the zinc ions were four-coordinate with an N2O2 donor set and a slightly distorted tetrahedral geometry. The solid-state fluorescence properties indicate that the fluorescence peaks belong to the π*-π transition of the ligand PBM, which has a significant red shift and enhancement with the order being 1 > 2 > PBM. The stronger fluorescence of the complexes than the ligand is due to the immobilization of the ligand through coordination, which reduces the energy loss of thermal vibration. The π∙∙∙π conjugation in 1 results in a stronger fluorescence of 1 than 2. Therefore, coordination and π∙∙∙π conjugation will affect the fluorescence of complexes.

Synthesis, crystal structure and characterization of two new cobalt(II) metal–organic frameworks with 1,4-bis((1h-imidazol-1-yl)methyl) benzene and 1,3,5-tris[(1h-imidazol-1-yl)methyl]benzene ligands

Two novel CoII metal–organic frameworks {[Co(BIMB)2(H2O)2](SO4)·EG·3 H2O}n (I) and {[Co(TIMB)2](SiF6)}n (II) were hydrothermally synthesized by corresponding metal salt with organic ligands 1,3,5-tris[(1H-imidazol-1-yl)methyl]benzene (TIMB) or 1,4-bis((1H-imidazol-1-yl)methyl)benzene (BIMB). Crystal structural analysis reveals that they exhibit varied structures. Compound I contains two crystallographically unique CoII centers, each lying on an inversion center and having a slightly distorted octahedral environment. The BIMB ligands link the CoII cations to generate a three-dimensional porous framework with a 4-connected uninodal (65.8) topology. Compound II exhibits a two-dimensional sheeted metal-organic structure running parallel to the (0 0 1) plane, in which TIMB ligands join Co2+ centers having a six-coordinated octahedral structure. In the solid state, adjacent sheets are further bridged by guest SiF6 - anions via C–H…F hydrogen-bonding interactions, giving rise to a three-dimensional supramolecular network structure with a 2-nodal (3-c)2(6-c) net. The topological analysis suggests that the point Schläfli symbol of compound II is (43)2(46.66.83). In addition, their thermal stabilities have also been investigated.

Four POM-Viologen Color-Changing Materials with Fast Color Response under Various External Stimuli.

Four kinds of polyoxometalate (POM)-viologen compounds were synthesized by hydrothermal method, namely (1-cby)2·[H2(SiMo12O40)]·2H2O (1), (1-cby)2·[H2(SiW12O40)]·2H2O (2), (1-cby)2·(1,1'-bcby)2·{H4[Co4(H2O)2(PW9O34)2]}·12H2O (3), (1-cby)·(1,1'-bcby)·[H(α-PW11O39)CoII(1-cby)]·8H2O (4) (1-cby·Br = 1-Cyclopropylmethyl-[4,4']bipyridinyl-1-ium bromide, 1,1'-bcby·Br = 1,1'-Bis-cyclopropylmethyl-[4,4']bipyridinyl-1-ium bromide). These four POM-viologen compounds exhibit one-dimensional supramolecular network structures. Especially, compound 3 contains a rare sandwich POM subunit {Co4(H2O)2(PW9O34)2}10-. These four compounds can be used as color-changing materials, and they all exhibit noticeable color changes upon exposure to light, heat, and electricity. The discoloration mechanism involves viologen derivatives with electron-deficient properties accepting electrons from POM with electron-rich properties under external stimulation, leading to the formation of viologen free radicals. Among them, compounds 1 and 2 also have good properties for ink-free erasable printing, double anticounterfeiting, and ultraviolet detector because of their rapid color response to ultraviolet (UV) light. In addition, compounds 1-4 also show different color changes in the detection of volatile amines.

Synthesis, structure, theoretical calculation and antibacterial property of two novel Zn(II)/Ni(II) compounds based on 3, 5-dichlorosalicylaldehyde thiocarbamide ligand

Two new compounds namely [Zn(L1)phen]31 and Ni(L1)phen(MeOH) 2 (L1 = 3, 5-dichlorosalicylaldehyde thiosemicarbazone) were synthesized by the slow evaporation method at room temperature. The structure of ligand L1 was determined using 1H NMR and 13C NMR spectra. X-ray single crystal diffraction analysis revealed that compounds 1–2 can form 3D supramolecular network structures through π···π stacking and hydrogen bonding interactions. The DFT calculation shows that the coordination of ligand and metal is in good agreement with the experimental results. Hirshfeld surface analysis revealed that H…H and Cl…H interactions were the predominant interactions in compounds 1–2. Energy framework analysis indicated that dispersion energy played a dominant role in the energy composition of compounds 1–2. The inhibitory effects of compounds 1–2 against Escherichia coli (E. coli) and Methicillin-resistant Staphylococcus aureus (MRSA) were tested using the paper disk diffusion method (1: E. coli: 18 mm, MRSA: 17 mm, 2: E. coli: 15 mm, MRSA: 16 mm). Ion releasing experiments were conducted to assess the ion release capacity of compounds 1–2 (Zn2+, 4 days, 38.33 µg/mL; Ni2+, 4 days, 29.12 µg/mL). Molecular docking demonstrated the interaction modes of compounds 1–2 with UDP-N-acetylenolpyruvoylglucosamine reductase (MurB) and dihydrofolate reductase (DHFR) in bacteria, involving hydrophobic, stacking, hydrogen bonding and halogen bonding interactions. The generation of reactive oxygen species (ROS) in bacteria under the presence of compounds 1–2 were evaluated using a fluorescent dye known as dichlorodihydrofluorescein diacetate (DCFH-DA). Potential antibacterial mechanisms of compounds 1–2 were proposed.

Design of Self-healing and Tough Materials Using Supramolecular Network Structures

Design of Self-healing and Tough Materials Using Supramolecular Network Structures

Metal-Phenolic Networks for Chronic Wounds Therapy.

Chronic wounds are recalcitrant complications of a variety of diseases, with pathologic features including bacterial infection, persistent inflammation, and proliferation of reactive oxygen species (ROS) levels in the wound microenvironment. Currently, the use of antimicrobial drugs, debridement, hyperbaric oxygen therapy, and other methods in clinical for chronic wound treatment is prone to problems such as bacterial resistance, wound expansion, and even exacerbation. In recent years, researchers have proposed many novel materials for the treatment of chronic wounds targeting the disease characteristics, among which metal-phenolic networks (MPNs) are supramolecular network structures that utilize multivalent metal ions and natural polyphenols complexed through ligand bonds. They have a flexible and versatile combination of structural forms and a variety of formations (nanoparticles, coatings, hydrogels, etc.) that can be constructed. Functionally, MPNs combine the chemocatalytic and bactericidal properties of metal ions as well as the anti-inflammatory and antioxidant properties of polyphenol compounds. Together with the excellent properties of rapid synthesis and negligible cytotoxicity, MPNs have attracted researchers' great attention in biomedical fields such as anti-tumor, anti-bacterial, and anti-inflammatory. This paper will focus on the composition of MPNs, the mechanisms of MPNs for the treatment of chronic wounds, and the application of MPNs in novel chronic wound therapies.

Novel polymeric organic gelator as lost circulation material for oil-based drilling fluids

With the exploitation of unconventional oil and gas resources towards deep and ultra-deep formations, oil-based drilling fluids (OBDFs) with white oil as a base oil have been increasingly employed in China to achieve safe, efficient, and fast drilling operations. However, due to the lack of effective lost circulation material (LCM), drilling time and drilling fluids are severely delayed and extra consumed, respectively. Herein, we innovatively propose and successfully develop a polymeric organic gelator using an emulsifier-free emulsion polymerization method and find that it achieves remarkable plugging ability in OBDF, superior to commercial LCMs, including asphalt, fine calcium carbonate, elastic graphite, and rubber particles. In detail, SMHDV with a branched C8 pendant group, benzene ring, isopropyl, and acetate groups is homogeneously dispersed in OBDF after hot rolling and capable of blocking permeable porous formations, resulting in a reduction of the cumulative filtration by 68 % at a concentration as low as 1 wt%. When added at a high concentration above 10 wt%, SMHDV turned into an organogel which can block cracks and prevent severe lost circulations together with other bridging materials. Furthermore, SMHDV maintains considerable plugging capacity in a wide temperature range of 80–150 °C, which meets most requirements of oil wells. The superior performance is attributed to the formation of supramolecular network structure in white oil due to the self-assembly behavior, which originated from the appropriate hierarchical polarities. In addition, the material can maintain stable rheological properties after hot rolling, improving the electrical stability of the drilling fluid. It is expected to form a set of scientific and efficient OBDF plugging technology to solve the leakage problems encountered during drilling.

A blue emission of zirconium (IV) complex based on 2, 6-pyridinedicarboxylic acid ligand: Syntheses, crystal structure, and luminescence sensing

A novel blue emission of zirconium complex, formulated as [Zr(pydc)3]·[(CH3)2NH2]2 (1), has been synthesized by using a mixture of zirconium nitrate and 2, 6-pyridinedicarboxylic acid (H2pydc). The complex 1 presents a three-dimensional supramolecular network structure due to the intermolecular NH···O, OH···O hydrogen bonds. Additionally, the crystals of 1 exhibit blue luminescence and demonstrate a highly selective and sensitive sensing capability for detection of Co2+ ions with a Ksv value of 1.22 × 104 M−1 and limit of detection (LOD) of 1.20 × 10−5 M. Furthermore, the fluorescence lifetime and quantum yield of the complex 1 is τ = 6.22 μs and Φ = 25.9 %.

Synthesis, crystal structure, fluorescence properties, and theoretical studies of a dinuclear Ni(II) complex derived from a quinoline-containing half-salamo-type ligand

A quinoline-containing semi-salamo-type ligand, HL, was synthesized and a dinuclear Ni(II) complex, [Ni2(L)2(NCS)2], was produced. The complex was experimentally analyzed by elemental analysis, fluorescence, and UV–Vis spectroscopy. X-ray single crystal diffraction experiments showed that the complex is a six-coordinate, structurally symmetric, phenoxy-bridged dinuclear Ni(II) dimer with the participation of SCN− in the coordination to satisfy charge neutrality. The self-assembly forms a 2-D supramolecular network structure through hydrogen bonding and π⋯π interactions. DFT calculations were performed on the complex to analyze its energy gaps, and UV–Vis experiment was verified by TD-DFT calculation. In addition, close intermolecular contacts were investigated by Hirshfeld surface analysis to quantify the crystal structure interaction.

Dynamically Visualized Mechano-Responsive Supramolecular Self-Assembly System for Small Molecule Release.

The mechano-responsiverelease of small molecules has received extensive attention in ultrasound (US)-controlled drug release in recent years because it can achieve non-invasive, spatiotemporally controlled precise drug release. However, the vast majority of small molecules mechano-release reported so far are based on polymer systems, which suffer from complex preparations and single mechano-response. Here, an isoguanosine (isoG) visualized mechano-responsive supramolecular self-assembly (isoG-VMRSS) system was successfully constructed by a one-pot reaction. It is completely composed of small molecules, which allows for multiple mechano-responsive releases of isoG (at least 9 times) and ultimately has potential for application in US drug release. A combined experimental-computational approach reveals the supramolecular network structure (formed by the joint action of related metal coordination bonds, boronate ester bonds and hydrogen bonds mediated by isoG) gradually formed inside the system is the underlying internal mechanism. Therefore, it provides a new and effective idea of small molecule release in the field of mechanochemistry.

The investigation of two bis(phenoxo)-acetate-bridged binuclear nickel(II) complexes driven by different alcohol solvents

Two solvent-induced bis(phenoxo)-acetate-bridged binuclear Ni(II) complexes, [Ni2(L)(µ-OAc)(CH3OH)] (1) and [Ni2(L)(µ-OAc)(H2O)] (2), were synthesized with a bis(salamo)-like ligand H3L and Ni(OAc)2·4H2O in two different alcohol solvents (methanol and ethanol). Complexes 1 and 2 were described by elemental analyses, single crystal X-ray diffraction, IR spectra, UV–vis spectra and fluorescence spectra. Complexes 1 and 2 have analogous crystal structures, but the non-covalent interactions are distinct. The one-dimensional chain of 1 is formed by π–π interactions, and the three-dimensional supramolecular network structure of 2 is formed by intermolecular hydrogen bonding interactions. In addition, fluorescence experiments indicated that the fluorescence of 1 and 2 undergoe a significant quenching compared to H3L. Intermolecular forces were investigated using Hirshfeld surface analysis. DFT calculations showed that 1 and 2 have high chemical reactivity and low kinetic stability.

Formulation and characterization of nanoemulsions stabilized by nonionic surfactant and their application in enhanced oil recovery

Nanoemulsions are kinetically stable emulsions with droplet size distribution in the range of 10–500 nm. Low interfacial tension (IFT), small droplet size, and wettability alteration properties of nanoemulsions have led to their application for enhanced oil recovery (EOR) EOR. The current study deals with the formulation and characterization of Tergitol 15-S-9 surfactant stabilized oil/water nanoemulsion (NE). Optimal surfactant concentration accompanied by optimal salinity determination was done by observing long-term stability. The stability of the nanoemulsions was analyzed by Turbiscan and Zeta potential analysis. The optimal nanoemulsion was characterized in terms of droplet size, rheology, wettability, miscibility, and IFT. All the prepared nanoemulsion showed particle size < 300 nm. optimized nano emulsion, that is, 0.5 wt.% surfactant +0.5 wt.% salinity showed good IFT reduction and wettability alteration capability. Nanoemulsion also showed good miscibility behavior with actual crude oil at 60 °C. Rheology of the formed emulsion shows a mixed nature that is shear thinning as well as shear thickening nature which is favorable for heterogeneous reservoirs. Core-flooding experiments were conducted at optimized nanoemulsion formulation, and additional oil recovery of 13.93% of the original oil in place was obtained after the conventional water flooding. Highlights Experimental and mechanistic investigation of nanoemulsions for oil recovery. Enhanced miscibility of Tergitol 15-S-9 stabilized nanoemulsion with crude oil. Viscosity enhancement by macromolecular and supramolecular network structures. Low IFT achieved for the nanoemulsion resulting enhanced oil displacement. Encouraging oil displacement by injection of formulated nanoemulsion.

Copper(II) and zinc(II) complexes bridged by benzenoid aromatic oxocarbon and dicarboxylate dianions

A novel series of Cu(II) and Zn(II) complexes were constructed through the bridging croconate (C5O5)2−, squarate (C4O4)2− and 2,5-pyridine-dicarboxylate (Py2,5-dc)2− dianions. These include pent- [Cu5(epdmpy)4(C5O5)2(H2O)6](ClO4)6‧12H2O (1) and tri-nuclear [Cu3(bepza)2(Py2,5-dc)2(ClO4)2(H2O)2]‧2H2O (4), dinuclear [Zn2(MeDPA)2(C4O4)(H2O)4](ClO4)2 (7), and 1-D- coordination polymers (CPs) catena-{[Cu2(bpzpy)2(C5O5)](ClO4)2‧MeOH} (2) and catena-{[Zn(4,4′-bipy)(H2O)4](C5O5)(H2O)} (6) as well as the mononuclear [Cu(HBph2,2′-dc)(pmdien)]ClO4 (5) have been synthesized and spectroscopically characterized as well as by single crystal X-ray crystallography. The reaction of aqueous solution Cu(ClO4)2, pymeea and C5O52− resulted in the unprecedently bis(oxalato) [Cu2(Pymeea)2(C2O4)(ClO4)2(H2O)2] (3). In these complexes, (C5O5)2−, squarate (C4O4)2− and (Py2,5-dc)2− ligands display a variety of coordination bonding modes. In complexes 1 and 2 the croconato is binding as 1,2-bidentate-3-monodentate but in addition 5-mono-dentate semi-coordinate bonding was detected for 2, whereas in 6 as counter dianion. The bonding mode in the squarato 7 was achieved through the trans μ1,3-mono-dentate. In the di-carboxylato compounds, only five-membered chelate ring was formed in 5via one of the carboxylate groups, whereas in 4 bridging was conducted through a mono-carboxylate and five-membered chelate ring including the second carboxylate and pyridyl nitrogen. In complexes 1–5 and 7, hydrogen bonds of type OH⋯O and/or NH⋯O are connecting the complex cations with the perchlorate anions/ligands to generate different dimensional supramolecular network structures, whereas in 6, the 3D network was formed through hydrogen bonding between the coordinated aqua and lattice water molecules. Non-covalent ring⋯ring interactions were also observed between pyridyl rings in complexes 1, 6 and 7, and between pyrazolyl rings as well as pyridyl ring in 2.

Strong and tough collagen/cellulose nanofibril composite films via the synergistic effect of hydrogen and metal–ligand bonds

In this paper, the collagen (COL)/cellulose nanofibril (CNF) composite films were fabricated via solution casting-solvent evaporation induced COL molecule self-assembly in CNF supramolecular network to form a high-density physically crosslinked supramolecular double network and then moved to inorganic saline solutions to induce the structure rearrangement and crosslinking of the composite films on the nanoscale through soaking. The supramolecular double network structure and synergistic effect of hydrogen and metal–ligand bonds on the mechanical properties of the COL/CNF composite films were also investigated through various characterization techniques to thoroughly comprehend the reinforcement mechanism. COL/CNF composite films with ferric ion exhibited excellent thermal stability, outstanding dry and wet mechanical performances (112.7 MPa and 55.5 MPa). Additionally, the composite films displayed super bioactivity and antimicrobial activity even in the presence of metal ions, making them promising materials for tissue engineering and regenerative medicine.

Design of Acrylate-Terminated Polyurethane for Nylon Seamless Bonding Fabric Part I: Design of the End-Capping Thermoplastic Polyurethane Adhesive with Acrylate Copolymer.

This series of studies aims to design acrylate-terminated polyurethanes for use in nylon seamless bonded fabrics. The first part used N,N-dimethylacrylamide (DMAA) and methyl methacrylate (MMA) to replace the chain extender in polyurethane synthesis as end-capping agent to synthesize thermoplastic polyurethane (TPU) adhesive. The molecular weight of the TPU is controlled to further influence the mechanical and processing properties of the polyurethane. Here, polytetramethylene ether glycol (PTMG) and 4,4-methylene diphenyl diisocyanate (MDI) were polymerized, and then a blocking agent was added thereto. The results show that the characteristic peaks of benzene ring and carbamate of TPU adhesive are at 1596 cm−1 and 1413 cm−1, respectively, while the characteristic peaks of DMAA are at 1644 cm−1 and 1642 cm−1 in the FT-IR spectrum. There is an absorption peak –N=C=O– which is not shown near 2268 cm−1, which proves that the structure of TPU contains the molecular structure of capping agent, PTMG and MDI. When the DMAA concentration in the capping agent was increased from 3.0 wt% to 10 wt%, the –C=O (H-bond) area percentage of hydrogen bonds formed at 1711 cm−1 increased from 41.7% to 57.6%, while the –NH (H bond) produced at 3330 cm−1 increased from 70% to 81%. These phenomena suggest that increasing the concentration of DMAA capping agent can effectively promote the formation of complex supramolecular network structures by hydrogen bonding in TPU. The content and concentration of the capping agent affects the molecular weight of the TPU. Chain growth is terminated when molecular weight growth can be effectively controlled and reduced. It was observed in thermal analysis that with increasing DMAA concentration in the molecular structure, the concentration of capping agent in TPU, hydrogen bonding force between hard segments, melting point (Tmh) and melting enthalpy (ΔH) all increased the capping agent. The pyrolysis temperature of TPU is increased by 10–20 °C.

Synthesis and structure of a 3D supramolecular layered Bi-MOF and its application in photocatalytic degradation of dyes

A self-assembled Bi-MOF {[Bi(BDC)1.5(DMF)(H2O)]·DMF}n(Bi-BDC) (H2BDC = terephthalic acid, DMF = N, N-dimethylformamide) was designed and synthesized by the reaction of bismuth nitrate and H2BDC under solvothermal conditions. The basic structure of the complex was characterized by elemental analysis, infrared spectroscopy, UV–vis spectroscopy, PXRD, single crystal X-ray diffraction and thermogravimetric analysis. The structure analysis shows that the Bi-BDC has a three-dimensional supramolecular layered network structure by p - π interaction. In addition, the properties of the Bi-BDC on photocatalytic degradation of organic dyes were investigated. Surprisingly, it has superior degradation rate for both anionic and cationic dyes with a very short time by adding hydrogen peroxide. Furthermore, the kinetic analysis, degradation of mixed dyes, recycle experiments and catalytic mechanism were investigated. The results show that Bi-BDC has potential application value in photocatalytic degradation of organic dyes in future.

High capacity for selective adsorption of anionic pollutants by a silver(I) 3D cationic supramolecular constructed from a flexible dithione ligand

A new cationic 3D-supramolecular coordination polymer namely, {[Ag3(Prbit)2 (CF3SO3)] [PF6]2}n (Ag-SCP) was designed, synthesized, structurally elucidated by X-ray crystallography and converted into the nano-sized particles in order to use it for further applications. In its asymmetric unit, three different AgI centers with three distinguished coordination geometries were detected. The uncoordinated PF6-anions neutralize the positive charge associated with the complex. The structure was extended by the intermolecular hydrogen bonding interactions to form a 3D supramolecular network structure. The ligand has an anti-gauche conformation. The polymer has a substantial potential for adsorption of organic and inorganic pollutants. Furthermore, as a recyclable promising prototype the nano–sized polymer displays a fast, efficient and reversible adsorption of Cr(VI) from the Cr(VI)-containing aqueous solutions. The influence of various factors such as initial concentration of the Cr(VI) ions, weight of the nano-sized Ag-SCP, pH and contact time on the adsorption efficiency of Cr(VI) were examined by the central composite design (CCD) method. Under the optimum conditions and desirable function value of 1.0, the adsorption percentage of Cr(VI) ions was to be 97%. Regression analysis with an R2 value of 0.99 indicates a satisfactory correlation between the obtained and predicted data. By virtue of these benefits, the presented supramolecular exhibits a high capture yield. Additionally, the adsorption of Cr(VI) by the nano Ag– SCP via anion exchange mechanism was dependent on the nature of the cationic network. Furthermore, the adsorbent exhibits a good capacity and selectivity for the adsorption of anionic dyes from the aqueous solutions.

A novel filler of biocomposites for long-term self-regulated delivery of immunomodulatory and antibacterial components to accelerate bone regeneration

Undesirable immune response and bacterial infection still remain critical challenges for the applications of biodegradable scaffolds. Herein, we assembled tannic acid (TA)/Zn2+ based metal-phenolic network complexes (MPNs) as a novel filler to render the scaffold with immunomodulatory and antibacterial functions. Besides the unique characteristics of combining the advanced functions of both TA (immunomodulation) and Zn2+ (antibacteria), another prominent feature of the filler was that it allowed to release its components in a sustainable constant rate manner, without initial burst release, lasting for more than 30 days, due to the supramolecular network structures and dynamic coordination bonds. Consequently, the modified scaffold could not only control the initial severe acute inflammation to a moderate level, but also displayed a full-course inhibition on later biodegradation-induced chronic inflammation. The manipulated anti-inflammatory micro-environment was more beneficial for in vivo osteogenesis. Additionally, the constant release rate of Zn2+ rendered the scaffold stable and long-term antibacterial performance, meanwhile avoiding cytotoxicity of Zn2+. As an emerging class of multi-functional metal-organic materials with a high degree of function modularity in terms of the choice of different metal ions and phenolic ligands, this work paved a new path for the applications of MPNs to advance multi-functional biocomposites.

Supramolecular Network Structured Gel Polymer Electrolyte with High Ionic Conductivity for Lithium Metal Batteries.

Polymer-based solid electrolytes (PSEs) offer great promise in developing lithium metal batteries due to their attractive features such as safety, light weight, low cost, and high processability. However, a PSE-based lithium battery usually requires a relatively high temperature (60°C or above) to complete charge and discharge due to the poor ionic conductivity of PSEs. Herein, a gel polymer electrolytes (GPEs) film with a supramolecular network structure through a facile one-step photopolymerization is designed and developed. The crosslinked structure and quadruple hydrogen bonding fulfil the GPEs with high thermal stability and good mechanical property with a maximum tensile strain of 48%. The obtained GPEs possess a high ionic conductivity of 3.8 × 10-3 S cm-1 at 25°C and a decomposition voltage ≥ 4.6V (vs Li/Li+ ). The cells assembled with LiFePO4 cathode and Li anode, present an initial discharge specific capacity of 155.6mAhg-1 and a good cycling efficiency with a capacity retention rate of 81.1% after 100 charges/discharge cycles at 0.1 C at ambient temperature. This work encompasses a route to develop high performance PSEs that can be operated at room temperature for future lithium metal batteries.

Synthesis, crystal structure and characterization of two new metal-organic frameworks with 1,3,5-tris[(1H-imidazol-1-yl)methyl]benzene and cyclohexane-1,3,5-tricarboxylate ligands

Two new metal-organic frameworks (MOFs) {[Cu3(timb)2(chtc)2]·14H2O}n, (I) and {[Co3(timb)2(chtc)2]·6H2O}n, (II) were hydrothermally synthesized by corresponding metal salt with mixed organic ligands of 1,3,5-tris[(1H-imidazol-1-yl)methyl]benzene (timb) and cyclohexane-1,3,5-tricarboxylic acid (H3chtc). Crystal structural analysis reveals that they exhibit varied structures. In the MOFs (I), CuII adopts an four coordination geometry, timb and cyclohexane-1,3,5-tricarboxylate ligands bridge neighboring CuII centers to result in two different one-dimensional knotted chains along the [0 − 1 2] and [1 0 − 1] directions, respectively. The two kinds of chains intersect each other vis CuII centers, resulting in a two-dimensional layered structure running parallel to the (1 2 1) plane. Adjacent layers are further linked by water moleculars via classical O–H…O hydrogen-bonding interactions, giving rise to a three-dimensional supramolecular network structure in the solid state. While in MOFs (II), the cyclohexane-1,3,5-tricarboxylate anions link the CoII cations to generate a two-dimensional sheeted metal-organic structure running parallel to the bc plane. Adjacent sheets are further bridged by timb ligands, forming a porous three-dimensional metal-organic framework with a rare (3, 4)-connected (6.82)2(62.84)3(62.8)2 topology. The solvent water molecules guest in the micropores of porous framework via water-carboxylate O–H…O hydrogen bonds. In addition, their thermal stabilities have also been investigated.