1D Coordination Research Articles

Coordination polymer derived transition metal phosphide/carbon composites for bifunctional oxygen electrocatalyst

Developing nonprecious electrocatalysts with bifunctional performances for oxygen reduction (ORR) and evolution reactions (OER) remains a crucial challenge in rechargeable Zn-air batteries (RZABs). In this study, we report the synthesis of a three-dimensional (3D) porous N, P-doped carbon-wrapped cobalt phosphide composite (Co2P@3DNPC) via direct calcination of a novel organic/inorganic porous coordination polymer by an in-situ phosphating strategy. DFT calculations demonstrate the intricate interactions occurring during the PEI-directed grinding self-assembly process among Co2+, phytic acid (PA), and polyethylenimine (PEI). Specifically, Co2+ ions initially adsorb onto PEI molecules before integrating with PA to form a 3D coordination polymer matrix. As-fabricated Co2P@3DNPC composite exhibits impressive ORR/OER bifunctional performances, with a half-wave potential of 0.78 V and an overpotential of 1.71 V, respectively. Its bifunctional activities enable a power density of 148.5 mW cm–2 in rechargeable ZABs, with remarkable stability (> 480 h) during a discharge-charge cycle. The interconnected porous structure and embedded Co2P nanoparticles optimize the electrode-electrolyte interfacial contact, boosting energy density and cycle life of as-assembled ZABs. This innovative approach paves the way for efficient, cost-effective production of bifunctional electrocatalysts for RZABs.

Discrete versus polymeric structures of coordination compounds of copper(II) with (pyridin-2-yl)methylenenicotinohydrazide and a library of dicarboxylic acids

A series of copper(II) discrete and polymeric coordination compounds, namely [{CuL(H2O)}2(fum)] (1), [{CuL(H2O)}2(mes)] (2), [Cu2L2(glu)]n·2n(H2O) (3·2n(H2O)) and [Cu3L2(adi)2]n (4) were fabricated from (pyridin-2-yl)methylenenicotinohydrazide (HL) and a library of dicarboxylic acids, namely fumaric acid (H2fum), mesaconic acid (H2mes), glutaric acid (H2glu) and adipic acid (H2adi), using evaporative crystallization, grinding and slurry synthesis methods. The obtained coordination compounds have been fully characterized by single crystal X-ray diffraction revealing different types of complexes depending on the linker length, viz. from dinuclear complexes for the shorter linkers (fumaric and mesaconic acids) to 1D and 2D coordination polymers for longer glutaric and adipic acids. Thermal stability and spectroscopic features (FTIR and diffuse reflectance) of complexes were also studied. For the nonpolymeric compounds 1 and 2, the supramolecular assemblies driven by a combination of antiparallel π-stacking and hydrogen bonding interactions have been studied and compared using DFT calculations, MEP surface analysis and a combination of QTAIM and NCIplot computational tools.

A new three-dimensional barium(II) coordination polymer constructed from N,N'-bis(glycinyl)pyromellitic diimide: microwave-assisted synthesis, structure, Hirshfeld surface analysis and properties.

A new three-dimensional (3D) coordination polymer, namely, poly[diaqua[μ5-2,2'-(1,3,5,7-tetraoxo-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole-2,6-diyl)diacetato]barium(II)], [Ba(C14H6N2O8)(H2O)2]n, (I), has been synthesized by the microwave-irradiated reaction of Ba(NO3)2 with N,N'-bis(glycinyl)pyromellitic diimide {BGPD, namely, 2,2'-(1,3,5,7-tetraoxo-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole-2,6-diyl)diacetatic acid, H2L}. The title compound was structurally characterized by single-crystal X-ray diffraction analysis and powder X-ray diffraction analysis, as well as IR spectroscopy. In the crystal structure of (I), the BaII ion is nine-coordinated by six carboxylate O atoms from five symmetry-related L2- dianions and one imide O atom, as well as two water O atoms. The coordination geometry of the central BaII ion can be described as a spherical capped square antiprism. One carboxylate group of the ligand serves as a μ3-bridge linking the BaII cations into a one-dimensional polynuclear secondary building unit (SBU). Another carboxylate group of the ligand acts as a μ2-bridge connecting the 1D SBUs, thereby forming a two-dimensional (2D) SBU. The resulting 2D SBUs are extended into a 3D framework via the pyromellitic diimide moiety of the ligand as a spacer. The 3D Ba framework can be simplified as a 5-connected hexagonal boron nitride net (bnn) topology. The intermolecular interactions in the 3D framework were further investigated by Hirshfeld surface analysis and the results show that the prominent interactions are H...O (45.1%), Ba...O (11.1%) and C...H (11.1%), as well as H...H (11.1%) contacts. The thermal stability, photoluminescence properties and UV-Vis absorption spectra of (I) were also investigated. The coordination polymer exhibits a fluorescence emission with a quantum yield of 0.071 and high thermal stability.

2D coordination polymers of cadmium(II) and zinc(II) derived from N,N'-bis(glycinyl)pyromellitic diimide: microwave-assisted synthesis, structures, spectroscopic properties and influence of metal-ion size.

Two new two-dimensional (2D) coordination polymers (CPs), namely, poly[diaqua[μ4-2,2'-(1,3,5,7-tetraoxo-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole-2,6-diyl)diacetato-κ4O:O':O'':O''']cadmium(II)], [Cd(C14H6N2O8)(H2O)2]n (1), and poly[[tetraaqua[μ4-2,2'-(1,3,5,7-tetraoxo-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole-2,6-diyl)diacetato-κ4O:O':O'':O'''][μ2-2,2'-(1,3,5,7-tetraoxo-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole-2,6-diyl)diacetato-κ2O:O']dizinc(II)] dihydrate], {[Zn(C14H6N2O8(H2O)2]·H2O}n (2), have been synthesized by the microwave-irradiated reaction of Cd(CH3COO)2·2H2O and Zn(CH3COO)2·2H2O, respectively, with N,N'-bis(glycinyl)pyromellitic diimide {BGPD, namely, 2,2'-(1,3,5,7-tetraoxo-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole-2,6-diyl)diacetic acid, H2L}. In the crystal structure of 1, the CdII ion is six-coordinated by four carboxylate O atoms from four symmetry-related L2- dianions and two coordinated water molecules, furnishing an octahedral coordination geometry. The bridging L2- dianion links four symmetry-related CdII cations into a 2D layer-like structure with a 3,4-connected bex topology. In the crystal structure of 2, the ZnII ion is five-coordinated by three carboxylate O atoms from three different L2- dianions and two coordination water molecules, furnishing a trigonal bipyramidal coordination geometry. Two crystallographically independent ligands serve as μ4- and μ2-bridges, respectively, to connect the ZnII ions, thereby forming a 2D layer with a 3,3-connected hcb topology. Crystal structure analysis reveals the presence of n→π* interactions between two carbonyl groups of the pyromellitic diimide moieties in 1 and 2. CP 1 exhibits an enhanced fluorescence emission compared with free H2L. The framework of 2 decomposes from 720 K, indicating its high thermal stability. A comparative analysis of a series of structures based on the BGPD ligand indicates that the metal-ion size has a great influence on the connection modes of the metal ions due to different steric effects, which, in turn, affects the structures of the SBUs (secondary building units) and frameworks.

3D coordination polymers with N-heterocyclic Ga(I) moieties

The reactions of bimetallic acenaphthene-1,2-diimine complex [(Dpp-bian-GaCr(CO)5]2- [Na(Thf)2]2(I) (Dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) with 4,4ʹ-bipyridine (4,4ʹ-Bipy) and 1,3-bis(4-pyridyl)propane (Bpp) in THF gave 3D coordination polymers [{(Dppbian) GaCr(CO)5}{Na(4,4ʹ-Bipy)3}]n(II) and [(Dpp-bian)GaCr(CO)4Na(Et2O)(Bpp)1,5]n(III), respectively. Compounds II and III were characterized by elemental analysis and NMR and IR spectroscopy. The molecular structure of IIwas established by X-ray diffraction (CCDC no. 2278024).

Synthesis, characterization, crystal structures and catalytic activity of hydrogen bond mediated 2D and 3D-copper(II) coordination networks based on 2-aminoterepthalic acid and 5-aminoisopthalic acid

Two new copper(II) compounds [Cu2(2-NH2BDC)2(bipy)2(H2O)4] (1) and [Cu2(µ2OH)2(5-aip)(bipy)2(H2O)].5H2O (2) have been synthesized and characterized by elemental analyses, IR, thermogravimetric analysis, and electronic absorption spectroscopy. Molecular structures of compounds 1 and 2 were determined crystallographically. Single crystal X-ray studies show that the coordination network 1 is a centrosymmetrical dimeric unit with the 2-aminoterephthalate ligand bridging the two copper atoms. Each CuII atom is hexacoordinated, residing in an octahedral environment, surrounded by one oxygen and one nitrogen atoms from 2-aminoterephthalate ligand and two nitrogen atoms from one bipy ligand and two water molecules to give a CuO3N3 segmentand generate the an infinite three-dimensional (3D) supramolecular structure resulting from CH•••O interactions between adjacent dimer molecules running parallel to the a axis. In compound 2, each CuII atom is pentacoordinated, residing in a square pyramidal geometry and generate an infinite two-dimensional (2D) supramolecular structure resulting from CH•••O, NH•••O and OH•••O hydrogen bond interactions. The coordination network 1 and 2, on pyrolyzing, yielded copper oxide nanoparticles, which have been characterized by TEM and powder X-ray diffraction. The catalytic properties of the resulting copper oxide nanoparticles have also been studied for CN cross-coupling reactions with aryl halides. The CN coupling products were obtained in 70–99 % yields.

Zn(II)-based 2D coordination polymer bridged by isophthalate and Dipyridylsulphide : Structural characterisation, Schottky diode device and theoretical interpretation

The design of low cost, easy-to-prepare, soft-to-handle and sustainable material-based technology has been growing day-by-day. Coordination polymers (CPs) are such emerging materials those have been instructed as one of the premium resources to serve the electronic industry. In this aspect, we have designed a hetero-bridging Zn(II)-coordination polymer using two different bridging ligands - 4,4′-Dipyridylsulphide (4,4′-DPS) and 5-Nitroisophthalic acid (5-H2NIA), {[Zn(4,4′-DPS)2(5-HNIA)2(H2O)]n} (Zn-CP) and characterize the crystalline compound with Single Crystal X-ray diffraction (SCXRD) technique. The structure demonstrates that Zn-CP consists of two-dimensional (2D) network with distorted trigonal bipyramidal Zn(II) center (ZnN2O3). The self-assembly of 2D network by different non-covalent interactions forms three-dimensional (3D) supramolecular architecture. Hirshfeld surface analysis effectively evaluates the possibilities of non-covalent interactions present in Zn-CP. Density functional theory (DFT) based numerical calculation using crystallographic parameters has estimated the band gap 3.51 eV which implies the semiconducting nature of Zn-CP. This property has been endorsed by the determination of band gap from Tauc's plot (3.71 eV) using UV–Visible absorption data. The electrical conductivity of Zn-CP determined at room temperature is 8.54 x 10–7 S m-1. The DC activation energy of the device is 9.05 × 10–19 eV with the conductivity limit, 4.71 (Ω-m)-1 having Richardson constant, 7.07 × 10–10Am−2K−2and barrier height is 0.87 eV which suggests that the Zn-CP is n-type semiconductor. Thus, the present work may provide a facile pathway for laboratory-to-land application of such energy materials taking into consideration of technological aspect in the highly energy demanding era. Hence, the synthesized Zn-CP may have energy material application in the semiconducting industry.

Magnetic studies and Hirshfeld surface analysis of acetato bridged 2D Mn(II) coordination polymer with 4-aminobenzohydrazide ligand

A new acetato bridged 2D coordination polymer with general formula of [Mn(µ-4-ambh)(µ-OAc)(OAc)]n (1) was prepared by the reaction of Mn(OAc)2·4H2O with 4-aminobenzohydrazide (4-ambh) in equimolar ratio. The reaction was done in methanol under reflux condition and the single crystals of 1 were obtained by evaporation of the solvent. The structure of this compound was determined by X-ray analysis, and its spectroscopic properties and thermal stability were also studied. These studies indicated that in this compound, the manganese ions are connected by a mixture of acetate and 4-ambh bridges to form a 2D polymeric network at the bc crystallographic plane. The intermolecular and intramolecular interactions were investigated by Hirshfeld surface analysis. Magnetic studies revealed a dominant antiferromagnetic intermetallic coupling of J = −0.78 cm−1 magnitude. Magnetization measurements suggest a diamagnetic ground state and a small gap of 1.59 cm−1 with the first excited state; while the axial zero-field splitting parameter, D, was calculated at −0.21 cm−1.

Hexagonal-prismatic metal‒organic cages and metal‒organic polymers based on 1,1'-(5-methyl-1,3-phenylene)bis(1H-imidazole) ligand: Synthesis, structural characterization and magnetic property

A serial of hexagonal-prismatic metal organic cages (MOCs), [Co6(OH)2(HCOO)6(pbim)6(H2O)6]·SO4·2HCOO·8H2O (1·2HCOO·8H2O), [Ni6(OH)2(HCOO)6(pbim)6(H2O)6]·SO4·2HCOO·8H2O (2·HCOO·8H2O), {[Co6(μ3-OH)2(μ-HCOO)6(pbim)6(H2O)6]·ClO4}3+·3HCOO·solvent (3·3HCOO·solvent) and {[Ni6(μ3-OH)2(μ-HCOO)6(pbim)6(H2O)6]·ClO4}3+·3HCOO·solvent (4·3HCOO·solvent), was constructed from shuttlecock-like C3-symmetric [M3(μ3-OH) (μ-HCOO)3(H2O)3] (M = Co2+ or Ni2+) clusters generated in situ and a clip-like ligand 1,1'-(5-methyl-1,3-phenylene)bis(1H-imidazole) [pbim]. Interestingly, one SO42− or ClO4− anion was encapsulated in each cage of MOCs 1–4 through cooperative O–H⋯O and C–H⋯O hydrogen-bonding interactions. It was also found that those SO42‒-/ClO4−-encapsulated MOCs, especially SO42‒-encapsulated MOC of Ni2+, displayed quite stability in methanol. Notably, when the crystal parent solution of MOC 1 was disturbed or MOC 1 was immersed in its parent solution for a long time, it resulted in the formation of a 2D coordination polymer [Co(pbim)2(H2O)2]·2HCOO (5) with helical architecture. Unexpectedly, a novel 2D coordination polymer [Ni4(pbim)2(CH3O)4(C6H5COO)4]·2H2O (6·2H2O) based on in-situ produced cubane-like [Ni4(μ3-CH3O)4(μ-COO)2] cluster was solvothermally synthesized through the reaction of benzoic acid with relatively stable MOC 2 in DMF. Magnetic studies show that there are antiferromagnetic coupling exchanged by mixed hydroxyl/carboxylate bridges in shuttlecock-like [M3(μ3-OH) (μ-HCOO)3(H2O)3] clusters of 1 and 2 or in cubane-like [Ni4(μ3-CH3O)4(μ-COO)2] cluster of 6. The best fits for their magnetic behaviours gave the following coupling constants: J = −2.05 cm−1 for 1, J = −1.74 cm−1 for 2, and J1 = −2.85 cm−1 and J2 = −4.01 cm−1 for 6.

Dimers and 2D Networks of Adamantane-Related Ternary Organosilicon Coinage Metal Sulfide Clusters.

Adamantane-type organotin sulfide clusters were recently shown to react with coinage metal phosphine complexes under replacement of an organic substituent by a metal-phosphine unit. An extension of such studies involving the silicon-based congener [(PhSi)4S6] (A) revealed that the cluster core will be partly disassembled and a {PhSi} moiety is replaced by a coinage metal phosphine complex to form [(Et3PAg)3(PhSi)3S6] (B) and [Na2(thf)2.33][(Me3PCu)(PhSi)3S6] (C). Herein, we present an extension of this work upon variation of the reactants and reaction conditions. Besides the isolation of crystalline precursor complexes [CuCl(PMe2Ph)3] (1) and [AgCl(PMe2Ph)2]2 (2), the study addresses reactions of A with AgCl and a phosphine ligand in CH2Cl2, upon which A is completely disassembled to form [(Ph3P)3Ag(μ-S)SiCl2Ph] (3). In another case a CH2 group, most likely stemming from CH2Cl2, was attached to the ligand, thus generating [{PhCl(S)SiSCH2P(Ph2)CH2CH2}2] (4). Upon using CuCl and 1,4-bis(diphenylphosphino)butane (dppb) we isolated the phosphine-bridged analog of B, [{(dppbCu2)CuP(Ph2)(CH2CH2)(PhSi)3S6}2] (5). In order to receive the yet elusive silver homolog of C, we used PMe2Ph as a bulkier ligand. This way we generated a 2D coordination polymer of the desired composition, [Na2(thf)1.5][(Me2PhPAg)(PhSi)3S6] (6). UV-visible spectra of 6 indicated a bandgap of 3.89 eV, thus blue-shifted in regards to B and C.

Impact of Synthetic Variables on the Structural Diversity of TbIII-Carboxylate Frameworks: Gas Adsorption, Magnetism, and Organocatalysis Investigations.

In this work, three unique TbIII-carboxylate frameworks with the formula {[Tb2(OH)2(H2O)2(abtc)]·2H2O}n (1), {[Tb2(abtc)1.5(H2O)3(DMA)]·H2O}n (2) and {[Tb3(abtc)2.5(H2O)4]·H3O}n (3), each displaying structural variations, have been successfully synthesized by the solvothermal reactions of Tb(NO3)3·6H2O with the azo-containing ligand 3,3',5,5'-azobenzene tetracarboxylic acid (H4abtc) under varying conditions. Detailed single-crystal X-ray diffraction (SC-XRD) analysis manifested a remarkable diversity in these structures, demonstrating various coordination patterns of TbIII-metal nodes with the carboxylate groups of the organic linker, which contributed to the generation of intricate three-dimensional (3D) coordination networks with remarkable chemical resistance. Furthermore, frameworks 2 and 3, characterized by porous networks containing two and three independent TbIII-metal nodes, respectively, were both demonstrated to be efficient heterogeneous catalysts toward the cyanosilylation of imines under mild conditions with excellent reusability. In addition, direct current (Dc) magnetic susceptibility measurements conducted on frameworks 1, 2, and 3 indicated that there were obvious antiferromagnetic interactions among the TbIII-metal nodes, which suggests the involvement of intricate intra- and intertrimer exchange channels, adding another fascinating dimension to their physical properties.

2D Coordination Polymers of Zn(II) with Diethylmalonic Acid Dianions and 4,4´-bipyridine: Synthesis and Structures

2D Coordination Polymers of Zn(II) with Diethylmalonic Acid Dianions and 4,4´-bipyridine: Synthesis and Structures

(Invited) Electrochemical Random Access Memory for Neuromorphic Computing

Electrochemical random access memory (ECRAM) is a three terminal device that functions by tuning electronic conductance in functional materials through solid-state electrochemical redox reactions, and is one of several emerging device concepts that are currently being investigated in academic and industrial laboratories for enabling energy efficient brain inspired computing. Early demonstrations of nearly ideal analog switching and the realization that electrochemical ion insertion can be used to tune the electronic properties of many types of materials including transition metal oxides, layered 2D material, organic and coordination polymers, has sparked tremendous interest in ECRAM. Depending on the specific material, the resulting changes in conduction can range from gradual increments needed for analog elements, to large, abrupt changes for dynamically reconfigurable adaptive architectures. At its core, ECRAM shares many fundamental aspects with rechargeable batteries, where ion insertion materials are used extensively for their ability to reversibly store charge and energy. Computing applications, however, present drastically different requirements: systems will require many millions of devices, scaled down to less than 100 nanometers, all while achieving reliable electronic-state tuning at scaled-up rates (~109 Hz) and endurances (>1012 cycles), and with minimal energy dissipation and noise. In my presentation, I will briefly cover the history of ECRAM, the recent progress in devices spanning various types of materials, circuits, architectures, and discuss the rich portfolio of challenging, fundamental questions and how we can harness ECRAM to realize a new paradigm for low power neuromorphic computing.

In situ TEM Pyrolysis of Conductive 2D Coordination Polymers for Improved Application as Solid Acid Fuel Cell Electrode Materials

In situ TEM Pyrolysis of Conductive 2D Coordination Polymers for Improved Application as Solid Acid Fuel Cell Electrode Materials

2D Coordination Polymers of Zn(II) with Diethylmalonic Acid Dianions and 4,4'-bipyridine: Synthesis and Structure

2D Coordination Polymers of Zn(II) with Diethylmalonic Acid Dianions and 4,4'-bipyridine: Synthesis and Structure

Bimetallic Ba(II)-Cr(III) and trimetallic Ba(II)-Ln(III)-Cr(III) (Ln(III) = Gd, Tb, Dy, Ho, Er, Yb, Y) coordination polymers formed by Cr(III)-containing building blocks with cyclopropane-1,1-dicarboxylate anions

The reaction of chromium(III) nitrate with Ba(cpdc) (H2cpdc = cyclopropane-1,1-dicarboxylic acid) in a ratio of 1:3 yielded a 1D coordination polymer {[Ba2Cr2(OH)2(cpdc)4(H2O)8]·5H2O}n (1) formed by binuclear units [Cr2(OH)2(cpdc)4]4− and a 3D polymer [Ba2Cr(cpdc)3(NO3)(H2O)6]n (2) constructed from tris-chelate blocks [Cr(cpdc)3]3−. The addition of rare-earth metal nitrates (Cr:Ln = 1:2) in this reaction led to the formation of a series of trimetallic 3D coordination polymers {[Ba3Ln2Cr4(cpdc)12(H2O)24]·8H2O}n (3Ln, Ln = Gd, Tb, Dy, Ho, Er, Yb, Y), in whose structures tris-chelate fragments [Cr(cpdc)3]3− are bound in layers by Ln3+ ions and, further, in a framework due to the coordination of Ba2+ ions. The crystal structures of 1, 2, and 3Gd were determined by single-crystal X-ray diffraction (XRD), and isostructurality of all the compounds in the series 3Ln was proved by powder X-ray diffraction (PXRD). DC-magnetic susceptibility measurements revealed weak ferromagnetic exchange interactions between Cr3+ ions in compound 1 (J = +0.74 cm−1). According to ac-magnetic susceptibility measurements, complexes 3Er and 3Y exhibit field-induced slow relaxation of magnetization. According to the data of simultaneous thermal analysis (STA) and differential scanning calorimetry (DSC) performed under Ar atmosphere, dehydration of the compounds obtained takes place in one (for 1 and 3Gd) or three stages (for 2). The initial temperature of the organic part degradation process decreases when moving from compound 1 containing dimerized bis-chelate fragments [Cr2(OH)2(cpdc)4]4− (330 °C) to compounds 2 (276 °C) and 3Gd (261 °C) based on tris-chelate units [Cr(cpdc)3]3−.

Exploring the CO2 Electrocatalysis Potential of 2D Metal-Organic Transition Metal-Hexahydroxytriquinoline Frameworks: A DFT Investigation.

Metal-organic frameworks have demonstrated great capacity in catalytic CO2 reduction due to their versatile pore structures, diverse active sites, and functionalization capabilities. In this study, a novel electrocatalytic framework for CO2 reduction was designed and implemented using 2D coordination network-type transition metal-hexahydroxytricyclic quinazoline (TM-HHTQ) materials. Density functional theory calculations were carried out to examine the binding energies between the HHTQ substrate and 10 single TM atoms, ranging from Sc to Zn, which revealed a stable distribution of metal atoms on the HHTQ substrate. The majority of the catalysts exhibited high selectivity for CO2 reduction, except for the Mn-HHTQ catalysts, which only exhibited selectivity at pH values above 4.183. Specifically, Ti and Cr primarily produced HCOOH, with corresponding 0.606 V and 0.236 V overpotentials. Vanadium produced CH4 as the main product with an overpotential of 0.675 V, while Fe formed HCHO with an overpotential of 0.342 V. Therefore, V, Cr, Fe, and Ti exhibit promising potential as electrocatalysts for carbon dioxide reduction due to their favorable product selectivity and low overpotential. Cu mainly produces CH3OH as the primary product, with an overpotential of 0.96 V. Zn primarily produces CO with a relatively high overpotential of 1.046 V. In contrast, catalysts such as Sc, Mn, Ni, and Co, among others, produce multiple products simultaneously at the same rate-limiting step and potential threshold.

Two Three-Dimensional LnIII Coordination Polymers Exhibiting Luminescent Sensing and a Magnetocaloric Effect.

Two lanthanide 3D coordination polymers [Ln2(L)4Cl2(H2O)4]n (Ln = Eu (1), Gd (2)) with quinoline-2-carboxylic acid (HL) as the ligand were successfully synthesized and characterized. Complex 1 exhibits a highly sensitive and selective luminescent response to 2,6-dipicolinic acid (DPA) in tap water and is virtually unaffected by interferences such as amino acids, aromatic carboxylic acids, and ions. With the addition of DPA, the luminescence intensity of complex 1 decreases rapidly to the naked eye. The detection limit of 1 toward DPA is 3.36 μM, which is much less than the infectious dose (60 μM) of the anthrax spores, indicating the high sensitivity of 1 to DPA. This study offers a basis for employing lanthanide complexes in real sample analysis, enabling direct and efficient detection of DPA with high sensitivity and specificity. Additionally, it is noteworthy that at a magnetic field strength of 7 T and a temperature of 3 K, the maximum entropy change for complex 2 attains a value of 23.56 J kg-1 K-1.

Structural Regulation of Four New d10 Coordination Polymers and Their Fluorescent Detection Properties for Nitro Compounds in Water

Structural Regulation of Four New d10 Coordination Polymers and Their Fluorescent Detection Properties for Nitro Compounds in Water

Solid-state structural transformation triggered by water in zinc(Ⅱ) coordination polymers based on 3,5-ditertbutyl-2-hydroxybenzoic acid:Structural characterization and dielectric properties

Single-crystal-to-single-crystal (SCSC) transformation provides a good platform for obtaining new functional coordination polymers. In this study, we demonstrate a violent and rapid structural transformation between two d10 coordination polymers (CPs). The complex 1 [Zn(3,5-thbzc)2(C2H6O)2] transformed into the complex 2 {[Zn(3,5-thbzc)2(H2O)2]·C3H7NO·2H2O} (where t = tbutyl, hbzc− = 2-Hydroxybenzoato) triggered by deionized water under standard temperature and pressure conditions in solid state. The transformation reaction was confirmed using single-crystal XRD, PXRD and SEM. The results showed that complex 1 adopts a bidentate chelate six-coordination mode, and complex 2 adopts a monodentate four-coordination mode. SEM clearly showed that complex 2 was in the form of random nanowire clusters, suggesting that their transformation required degradation of the entire crystal structure. UV–Vis–NIR spectra were used to calculate the band gaps of complexes 1 and 2, which demonstrated wide-bandgap semiconductor-like materials with ∼3.2 eV band gap widths. The results of dielectric studies of complex 1 revealed that it possessed a medium dielectric constant (κ = 6.08 at 1 kHz), while complex 2 displayed an even higher dielectric constant (κ = 7.97 at 1 kHz) at room temperature. Interestingly, parent complex 1 exhibited a small ladder-like dielectric anomaly at 188 °C, while progeny complex 2 did not. This paper describes a new strategy for preparing adjustable functional dielectric materials.