Coordination Polymers Research Articles

Synthesis, characterization and adsorption of lead from water using 3-D metal carboxylate and nitrogen donor coordination polymer

Synthesis, characterization and adsorption of lead from water using 3-D metal carboxylate and nitrogen donor coordination polymer

Fabrication of two novel two-dimensional copper-based coordination polymers regulated by the “V”-shaped second auxiliary ligands as high-efficiency urease inhibitors

Two novel copper-based coordination polymers (Cu-CPs) had been presented based on mixed ligands. The synthetic Cu-CP-1 and Cu-CP-2 were derived from a combination of two distinct forms of “V”-shaped bis-pyridine-bis-amide ligands and 1,2,4-benzenetricarboxylic acid (1,2,4-H3BTC). Distinct grid windows were seen in the simplified two-dimensional (2D) layers of the Cu-CPs due to the variable length of ligand regulation. These Cu-CPs had the potential to act as urease inhibitors (UIs), and the mechanisms responsible for their inhibition were extensively studied. The results indicated that both Cu-CPs exhibited significant urease inhibitory activities with urease inhibition rates of 88.02 % and 88.87 % at 100 µM and semi-inhibitory levels of IC50 of 0.92 ± 0.05 µM and 0.87 ± 0.03 µM, respectively. Furthermore, the inhibitory activities of the Cu-CPs were higher than those of the standard thiourea. An investigation of the enzyme kinetics of the Cu-CPs using Lineweaver–Burk (L–B) plots at various inhibitor doses demonstrated their non-competitive inhibitory nature, enhancing our comprehension of the possible mechanism by which these Cu-CPs exert urease inhibition. Furthermore, molecular docking was used to verify the interactions between Cu-CPs and the urease active site. The findings of the urease inhibition studies were good, and the impact of Cu-CP complexes on urease inhibition was examined using density functional theory (DFT) simulations.

A Turn‐On Fluorescence Probe Based on a New Salamo‐Co (II) Coordination Polymer for Tyrosine Detection and Its Application in Water Samples

ABSTRACTA novel salamo‐Co (II) coordination polymer probe CP was synthesized firstly, and its crystal structure, [Co3(L)2(PTA)(H2O)2]n·4nDMF, was determined by X‐ray diffraction analysis. The probe has a rare aggregation‐induced luminescence enhancement (AIEE) effect. When applied to amino acid detection, it was found to have a high selective recognition of tyrosine. With the increase of tyrosine, the fluorescent strength of the probe was enhanced in a short period of time. In addition, the binding ratio of probe to Tyr was determined by fluorescence titration experiment, and the detection limit LOD of probe CP for Tyr was calculated to be 2.57 × 10−9 M, and the binding constant Ka was 2.96 × 105 M−1. According to UV absorption spectrum, FT‐IR spectra, ESI mass spectrometry, and DFT calculation, it was speculated that Tyr can bind to the probe after adding Tyr into the probe solution, triggering FRET and ICT effects, resulting in increased fluorescence intensity and blue shift, and finally achieving the specific recognition of tyrosine by probe CP. Finally, the practical application of probe CP was studied. Through strip test and real water sample test, it was found that the probe can be used for qualitative and quantitative analysis of tyrosine.

Therapeutic effects of DOX-loaded hydrogel MOF nanocarriers on triple negative breast cancer and derivative design via reinforcement learning

Triple negative breast cancer (TNBC) is one of the most difficult of all types of breast cancer to treat. TNBC is characterized by the absence of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. The development of effective drugs can help to alleviate the suffering of patients. The novel nickel(II)-based coordination polymer (CP), [Ni2(HL)(O)(H2O)3·H2O] (1) (where H4L=[1,1’:2’,1’’-triphenyl]-3,3’’,4’,5’-tetracarboxylic acid), was synthesized via solvothermal reaction in this study. The overall structure of CP1 was fully identified by SXRD, Fourier transform infrared spectroscopy and elemental analysis. Using advanced chemical synthesis, we developed Hyaluronic Acid/Carboxymethyl Chitosan-CP1@Doxorubicin (HA/CMCS-CP1@DOX), a nanocarrier system encapsulating doxorubicin (DOX), which was thoroughly characterized using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Thermogravimetric Analysis (TGA). These analyses confirmed the integration of doxorubicin and provided data on the nanocarriers’ stability and structure. In vitro experiments showed that this system significantly downregulated Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) in triple-negative breast cancer cells and inhibited their proliferation. Molecular docking simulations revealed the biological effects of CP1 are derived from its carboxyl groups. Using reinforcement learning, multiple new derivatives were generated from this compound, displaying excellent biological activities. These findings highlight the potential clinical applications and the innovative capacity of this nanocarrier system in drug development.

Energy transfer-mediated multiphoton synergistic excitation for selective C(sp3)–H functionalization with coordination polymer

Activation and selective oxidation of inert C(sp3)–H bonds remain one of the most challenging tasks in current synthetic chemistry due to the inherent inertness of C(sp3)–H bonds. In this study, inspired by natural monooxygenases, we developed a coordination polymer with naphthalenediimide (NDI)-based ligands and binuclear iron nodes. The mixed-valence FeIIIFeII species and chlorine radicals (Cl•) are generated via ligand-to-metal charge transfer (LMCT) between FeIII and chlorine ions. These Cl• radicals abstract a hydrogen atom from the inert C(sp3)–H bond of alkanes via hydrogen atom transfer (HAT). In addition, NDI converts oxygen to 1O2 via energy transfer (EnT), which then coordinates to FeII, forming an FeIV = O intermediate for the selective oxidation of C(sp3)–H bonds. This synthetic platform, which combines photoinduced EnT, LMCT and HAT, provides a EnT-mediated parallel multiphoton excitation strategy with kinetic synergy effect for selective C(sp3)–H oxidation under mild conditions and a blueprint for designing coordination polymer-based photocatalysts for C(sp3)–H bond oxidation.

Engineering Trifluoromethyl Groups in Porous Coordination Polymers to Enhance Stability and Regulate Pore Window for Hexane Isomers Separation.

Effective separation of hexane (C6) isomers is critical for a variety of industrial applications but conventional distillation methods are energy-intensive. Adsorptive separations based on porous coordination polymers (PCPs) offer a promising alternative due to their exceptional porosity and tunable properties. However, there is still an urgent need to develop PCPs with high stability and separation performance. This study investigates how substituting a methyl (-CH3) group with a trifluoromethyl (-CF3) group can regulate pores and hydrophobicity in PCPs. This precise adjustment aims to enhance stability and improve the kinetic separation performance of hydrophobic C6 isomers by considering the size and hydrophobicity of the trifluoromethyl group. Two isostructural PCPs with pcu topology, PCP-CH3 and PCP-CF3, were synthesized to vary pore diameters and hydrophobicity based on the presence of -CH3 or -CF3 groups. PCP-CF3 showed greater stability in water compared to PCP-CH3. While PCP-CH3 had high adsorption capacities, it lacked selectivity, whereas PCP-CF3 demonstrated improved selectivity, particularly in excluding dibranched isomers. Dynamic column separation experiments revealed that PCP-CF3 could selectively adsorb linear and monobranched isomers over dibranched isomers at room temperature. These findings highlight the potential of fluorine-modified PCPs for efficient isomer separation and underscore the importance of stability improvement strategies.

Synthesis of {AlMo14O44}-Based Supramolecular Structures with High Proton Conductivity.

Polyoxometalates (POMs) are esteemed for their remarkable stability and exceptionally high proton conductivity, rendering them ripe for extensive exploration owing to their research significance. Herein, we synthesized two bimolybdenum-capped {AlMoVI8MoV6O44} cluster-based coordination polymers through a solvothermal method. Single-crystal X-ray diffraction analysis elucidates that H[(H2bimb)3(AlMoVI8MoV6O44)] [bimb = 1,4-bis(imidazole-1-ylmethyl)benzene, compound 1] is the POMs-organic supramolecular structure. The introduction of zinc ions into the reaction environment facilitated the connection of initially dispersed ligands, which yielded the well-ordered structure H3[Zn2(bimb)4(AlMoVI8MoV6O44)]·4H2O (compound 2) with a layer distance of 11.8 Å. The proton conductivities (σ) of two compounds were measured under conditions of 85 °C and 98% relative humidity (RH), resulting in values of 3.89 × 10-2 and 4.76 × 10-2 S·cm-1, respectively. This study presents a novel approach to fabricating POMs as proton conductors through structural design and manufacturing adjustments.

Looking into the future of hybrid glasses.

Glasses are typically formed by melt-quenching, that is, cooling of a liquid on a timescale fast enough to avoid ordering to a crystalline state, and formerly thought to comprise three categories: inorganic (non-metallic), organic and metallic. Their impact is huge, providing safe containers, allowing comfortable and bright living spaces and even underlying the foundations of modern telecommunication. This impact is tempered by the inability to chemically design glasses with precise, well-defined and tunable structures: the literal quest for order in disorder. However, metal-organic or hybrid glasses are now considered to belong to a fourth category of glass chemistry. They have recently been demonstrated upon melt-quenching of coordination polymer, metal-organic framework and hybrid perovskite framework solids. In this Review, we discuss hybrid glasses through the lens of both crystalline metal-organic framework and glass chemistry, physics and engineering, to provide a vision for the future of this class of materials.

Construction of supramolecular assembly frameworks based on salamo-type polynuclear Cu(II) polymer and dimer utilizing secondary bonds

Using the advantages of the salamo structure, we successfully constructed a coordination polymer [Cu2(L)]n(ClO4)n (CP) and a coordination dimer [Cu4(L)2(EtOH)2](NO3)2 (CD). The CP has primary building unit [Cu2(L)], which contains a fully deprotonated part (L)3− and two Cu(II) ions. These units are infinitely connected by Cu-O coordination bonds to form a 1-D chain-like secondary building unit [Cu2(L)]n. The CD has primary building unit [Cu2(L)(EtOH)], which contains a fully deprotonated part (L)3−, two Cu(II) ions, and a coordinated ethanol molecule. Two primary building units are connected by Cu-O coordination bonds to form a dimer, which serves as the secondary building unit [Cu4(L)2(EtOH)2]. Both the CP and CD are stabilized through the formation of Cu-O coordination bonds and π···π interactions. Additionally, secondary bonds are used to form supramolecular assembly frameworks (SAFs). Reaction sites and secondary bonds were further analyzed and discussed through theoretical calculations including molecular orbitals (MO), molecular electrostatic potentials (MEPs), Hirshfeld surfaces (HS), Interaction Region Indicators (IRI), Localized Orbital Locator (LOL), and Electron Localization Function (ELF).

Influence of high cis-1,4-liquid polydienes on properties of carbon-black filled composites

High cis-1,4 liquid polybutadiene (cLBR) and polyisoprene (cLIR) with narrow molecular weight distribution were prepared by the chain-transfer coordination polymerization. The effects of cLBR and cLIR on the physical and dynamic mechanical properties of carbon-black filled composites containing single polybutadiene (PBR) or a blend of PBR/polyisoprene (PIR), were investigated. The results showed that cLBR and cLIR effectively ameliorated filler dispersion compared with the treated distillate aromatic extract (TDAE) oil. The wet skid resistance and rolling resistance of vulcanized PBR/PIR composites plasticized with 5 phr cis-1,4 liquid rubbers were significantly improved. Therefore, a new type of plasticizers cLBR and cLIR that are environmental benign and highly compatible with matrix rubbers, has been discovered to replace the conventional TDAE oil used in fabricating the “green” tyres.

A 2-D coordination polymer based on 3-(2-pyridyl)-5-(4-chlorophenyl)-1,2,4-triazine ligands and lead(II) bromide: synthesis, structure, luminescent properties, and application in organic light-emitting diodes

The combination of PbBr2 with 3-(2-pyridyl)-5-(4-chlorophenyl)-1,2,4-triazine (PCPT) results in a 2-D Pb(II) coordination polymer, denoted as [Pb9(PCPT)4Br18] n . This compound has been identified and studied through CHN analysis, FT-IR, and 1H NMR spectroscopy, in addition to detailed analysis using single-crystal X-ray diffraction techniques. Considering the primary and secondary Pb–N and Pb–Br bonds, Pb1 and Pb2 exhibit hemidirected pentagonal bipyramidal geometries, whereas Pb3, Pb4, and Pb5 demonstrate holodirected octahedral geometries. The 2-D structure transitions into a 3-D arrangement due to the presence of non-covalent C–H…Br and π…π stacking interactions. The interactions highlighted above enhance the structural stability and support the transfer of charge and energy between metal centers, positioning the polymer as a potential candidate for luminescence applications. Analysis of the electro-optical characteristics of this compound indicates its suitability as a luminescent material for incorporating into organic light-emitting diodes.

Synthesis, crystal structure, characterization and corrosion inhibition studies of a strontium coordination polymer with tartaric acid

The reaction of anhydrous strontium chloride with the proton transfer compound 1-H-Imidazolium Hydrogen- meso-tartrate in water resulted in the formation of polymeric tartrate complex of strontium which is characterised by SXRD, IR, UV-Visible and TG/DTG analyses. The single crystal X-ray diffraction analysis reveals that each strontium atom is eight coordinate with distorted dodecahedral arrangement. The two metal fragments are linked through central four-membered Sr2O2 ring and there is no imidazole moiety in the complex. The compound displays a rare crystallographic feature where a shared hydrogen atom is located between two carboxylic groups. This unusual arrangement of hydrogen atom with an occupancy factor 0.5, located in between two carboxylate groups balances the total charge of the structure. FT- IR study reveals the bidentate coordination mode of the ligand. The thermal behaviour of the compound was studied using TG/DTG analysis. Corrosion inhibition property of the title compound on mild steel in 1.0M HCl has been investigated using weight loss method. The formation of protective film on the mild steel surface is confirmed by Scanning Electron Microscopy images. The inhibition efficiency increases with increase in concentration of inhibitor.

Improved Optical Performance Analysis of YAG:Ce, NCS:Sm, and CAO:Mn Phosphors Physically Integrated with Metal-Organic Frameworks.

This research presents a thorough examination of the optical properties and performance enhancement strategies of synthesized phosphors, namely, yttrium aluminum garnet doped with cerium (YAG:Ce), sodium calcium silicate with samarium (NCS:Sm), and calcium aluminate oxide doped with manganese (CAO:Mn). The study delves into the synthesis processes of the phosphors, illumination of the crystal structures, and enhancement of luminescent characteristics. Additionally, the paper extends to the synthesis and analysis of {[Cu(μ3-dmg)(im)2]·3H2O} n (PKY159), and the coordination polymer (CP) was added the phosphors to explore a novel approach for enhanced optical performance. When the phosphor composites YAG:Ce, CAO:Mn, and NCS:Sm were made as poly(methyl methacrylate) (PMMA; for homogenization, stabilization) thin films with the coordination polymer PKY159 included, the intensity values increased by 97%, 96%, and 79%, respectively, in comparison to their pristine form. Also, all phosphors along with the PKY159 additive were examined for their decay time kinetics, thermal stabilities, CIE chromaticity coordinates, and quantum efficiencies. The YAG:Ce, NCS:Sm, and CAO:Mn mixes exhibit good thermal stability in addition to internal quantum efficiency (IQE) values that are much higher than the phosphors' additive-free form (95.6%, 66.3%, and 84.6%, respectively). This increase is correlated to an increase in steady-state measurements. These comprehensive analyses contribute valuable insights into the design and optimization of phosphor and coordination polymer blends for improved optical functionality.

Achieving Bright Up‐Conversion Luminescence of Eu3⁺ and Tb3⁺ Ions within Coordination Polymers

AbstractAchieving the up‐conversion luminescence (UCL) centered around trivalent lanthanide (Ln3+) ions in coordination polymers (CPs) is extremely challenging. Herein, Yb3⁺‐doped Ln‐CPs of [Eu1‐xYbx(pfbz)2(phen)Cl] (x = 0.3, namely 3; x = 0.5, namely 4; x = 0.7; namely 5), and [Tb1‐xYbx(pfbz)2(phen)Cl] (x = 0.2, namely 6; x = 0.5, namely 7; x = 0.6, namely 8) are reported by doping Yb3⁺ into Ln‐CPs of [Ln(pfbz)2(phen)Cl] (Ln = Eu, 1; Ln = Tb, 2). Both 5 and 8 visually exhibit excellent cooperative sensitization UCL of Eu3⁺ and Tb3⁺ ions, while 5 represents the first instance of an Ln‐CP where the UCL of Eu3⁺ ion is visually observable. Investigations into the UCL of these CPs reveal that the energy transfer is achieved through direct energy transfer from two individual Yb3⁺ ions, marking the first time such a mechanism has been employed in UCL in Eu/Tb‐CPs.

Insights into the Mechanism-Dependent Efficiency of the Electrocatalytic Oxygen Evolution Reaction on Octacarboxyphthalocyanine-Based Coordination Polymers

Insights into the Mechanism-Dependent Efficiency of the Electrocatalytic Oxygen Evolution Reaction on Octacarboxyphthalocyanine-Based Coordination Polymers

Coordinative Polyimides‐Ln3+ for Full‐Spectrum Luminescence with Applications in PLEDs and Acid‐Responsive Data Encryption

AbstractControllable coordination and efficient sensitization of rare earth ions in polymer materials are key to achieving high‐performance optoelectronic polymers. By designing aromatic diamines, polyimides are synthesized with 1,10‐phenanthroline benzimidazole groups (PBG) in the polymer backbone. Utilizing the coordination between PBG and rare earth ions (Eu3⁺, Tb3⁺), polyimide‐rare earth complexes are formed and precisely characterized their structures. The unique coordination allows PBG to effectively sensitize Eu3⁺, resulting in efficient, long‐lived red emission. Furthermore, PBG maintains excellent coordination with Eu3⁺ in acidic environments, granting acid‐responsive color changes for data encryption. Importantly, PBG sensitization of Tb3⁺ enabled full‐spectrum emission (CIE coordinates: (0.31, 0.35)) within a single rare earth‐polyimide complex, due to electron transfer among the ions, ligands, and polymer. This leads to the design of a multi‐layer PLED device with an optimal external quantum efficiency of 0.43% for white light emission (CIE coordinates: (0.28, 0.34)). Through comparative theoretical and experimental analysis, the photophysical behavior of these coordinated polyimides is explained and explored their photoluminescent and electroluminescent properties. This research integrates the advantages of rare earth elements and polyimides, creating novel luminescent polymers with diverse optical applications, providing a new strategy for designing luminescent coordination polymers.

Atomically dispersed iron sites from eco-friendly microbial mycelium as highly efficient hydrogenation catalyst

Iron, one of the most abundant elements on earth and an essential element for living organisms, plays a crucial role in our daily metabolism. In the field of catalysis, the development of high-performance catalysts based on less toxic iron element is also of significant importance for green chemistry and a sustainable future. To construct Fe-based heterogeneous catalysts with excellent hydrogenation performance, precise modulation of the atomic coordination structure is a key strategy for enhancing catalytic activity. In this study, we present an in-situ coating method for applying a zeolitic imidazolate framework (ZIF) onto the surface of fungal hyphae. The asymmetric coordination structure of Fe1-N3P1 was precisely tailored by utilizing the phosphorus source from the fungus and the nitrogen source in the ZIFs. Detailed characterizations and density functional theory calculations revealed that the incorporation of ZIFs not only increased the specific surface area of catalysts, but also facilitated the dispersion of Fe2P nanoparticles into the Fe1-N3P1 center, making the lowest reaction energy barrier and resulting in the best performance for nitrobenzene hydrogenation when compared to the Fe2P nanoparticles and clusters. This research introduces a novel design concept for constructing asymmetric monoatomic configuration based on the inherent characteristics of natural microorganisms and the exogenous porous coordination polymers.

Terphenyl-Tricarboxylate Coordination Polymers: From Hydrothermal Assembly to Structural Diversity and Catalytic Application

Terphenyl-Tricarboxylate Coordination Polymers: From Hydrothermal Assembly to Structural Diversity and Catalytic Application

Hofmann Clathrates: A "Blue Box" Approach to Modulate Spin-Crossover Properties.

Hofmann coordination polymers (CPs) with cationic ligands provide an innovative strategy for recognizing π-electron-rich aromatic molecules - similar to the "little blue box". In this study, we demonstrate that hydroquinone molecules can be incorporated into these coordination polymers when redox-active bipyridinium derivatives are used as axial ligands. The insertion leads to a significant structural modification, resulting in a shift of the spin transition by 150 K and an approximate 23 % increase in volume, caused by the strong donor-acceptor π-π stacking interaction formed between the ligands and the guest molecule. These findings have been confirmed through temperature-dependent single crystal X-ray diffraction, magnetic measurements and optical reflectivity measurements.

Hofmann Clathrates: A “Blue Box” Approach to Modulate Spin‐Crossover Properties

AbstractHofmann coordination polymers (CPs) with cationic ligands provide an innovative strategy for recognizing π‐electron‐rich aromatic molecules – similar to the “little blue box”. In this study, we demonstrate that hydroquinone molecules can be incorporated into these coordination polymers when redox‐active bipyridinium derivatives are used as axial ligands. The insertion leads to a significant structural modification, resulting in a shift of the spin transition by 150 K and an approximate 23 % increase in volume, caused by the strong donor‐acceptor π‐π stacking interaction formed between the ligands and the guest molecule. These findings have been confirmed through temperature‐dependent single crystal X‐ray diffraction, magnetic measurements and optical reflectivity measurements.