A novel dinuclear copper–iodine supramolecular compound exhibiting further enhanced capacitance after polyaniline modification and subsequent application in solid-state supercapacitors was successfully developed.

ABSTRACT This study employs a template‐directed assembly strategy to synthesize the first In 3+ /Cu 2+ heterometallic oxo cluster, {InCu 6 } . {InCu 6 } costabilized by l ‐(+)‐tartaric and acetic acids, features a central InO 6 octahedron surrounded by six Cu 2+ ions. Benchmarked against structurally analogous heterometallic oxo clusters, {InCu 6 } demonstrates superior proton conductivity of 7.95 × 10 −2 S cm −1 at 30°C and 90% relative humidity (RH). DFT calculations indicate that the introduction of In 3+ significantly reduces the energy barrier for proton detachment from the oxygen atoms in {InCu 6 } , thus elucidating the kinetic mechanism by which In 3+ /Cu 2+ synergy enhances the conduction efficiency. To translate this molecular performance into a functional device for humidity gradient‐based power generators (HGPGs), a novel cationic polymer ( PVA‐CTPP + Br − ) was designed and synthesized as the matrix to form a uniform PVA‐CTPP + ‐{InCu 6 } composite film. The resulting planar generator demonstrated stable performance, delivering an output of 0.63 V and 14.3 µA cm −2 at 92% RH and room temperature.

Precise control over the dimensional organization of molecular metal oxides remains an ongoing challenge in materials design. Herein, we report a "molecular editing" strategy for Dawson-type phosphotungstate (PW) clusters through systematic ligand engineering. By progressively increasing the complexity of polydentate arylphosphonic (Apa) ligands, we guide the structural evolution from zero dimensional (0D) molecular entities to three dimensional (3D) covalent cluster networks (CCNs). The resulting 3D CCN, PW-Apa(3), achieves ultrahigh proton conductivity (1.87 × 10-2 S cm-1, 303 K, 90% RH), surpassing its 0D counterparts by a factor of 20. Mechanistic investigations indicate that this enhanced performance can be attributed to optimized proton coupled electron transfer (PCET), enabled by a synergistic interplay between structural dimensionality and electronic modulation. PW-Apa(3) exhibits exceptional proton-conducting properties, enabling its integration into an ionic skin sensor capable of multimodal detection of mechanical deformation and humidity fluctuations. This advancement paves the way for a multifunctional ionic skin platform that mimics biological sensing.

Achieving higher proton conductivity of proton-conducting materials in solid-state is one of the utmost challenge in materials science. Due to their oxygen-rich structure and negative sur-face charge, poly xometalates (POMs) anions have high requirements for proton carrier density and proton mobility, and thus have great potential as proton conducting materials. Furthermore, the versatility in modifying the ligand environment or incorporating acidic functional groups in POMs allows for precise tuning of their proton conductivity and stability under operational con-ditions. Therefore, it is an effective strategy to select a suitable organic ligand to stabilize the [TeMogO21 anion assembled in-situ by covalent modification. In this paper, three [TeMogO21 anionic clusters have been designed and synthesized by using polydentate phosphonate lig-ands and guided by transition metals, H26[Co(N(CH2O3)(2)CH2COO))6(TeMogO21)4(H2O)]-64H2O (complex 1), Has Cus(N(CH3PO3)(2)CH2COO))(TeMogO214(H2O)6]-78H,0 (complex 2) and HNa2[Co(N-2(CH3)(2) (CH3PO4)(CH3PO4H1)) (TeMoO21)(PO) (H2O)161-84H2O (complex 3). Among them, complexes 1 and 2 are isomorphic, and complexes 1-3 have good proton conduction properties. resulting in values of 1.3 * 10 <^> - 2 1.22 * 10 <^> - 2 and 1.11 * 10 <^> - 2 * S / c * m respectively (75% relative humidity. 80 degrees C). This work offers a promising strategy for the development and design of novel telluromolybdate clusters suitable for proton conductive materials. (c) 2026 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

In this study, we employed sodium hydroxide and 2,6-pyridinedimethanol as modulators to tailor the structure of metal-organic crystals via "coordination modulation strategy". Based on this strategy, two copper-based crystalline materials were synthesized via hydrothermal synthesis and structurally characterized. Single-crystal X-ray diffraction analysis elucidates that [Cu2 ( & micro;2 -OH)( & micro;3 -OH)(H2 dcppa)(H2 O)] center dot H2 O (dcppa = 3-(3' ,5' -dicarboxyphenoxy)phthalic acid, CP-1 ) exist a kind of [Cu4 ( & micro;2 -OH)2 ( & micro;3 -OH)2 (H2 O)2 ]4 + cluster. Each [Cu4 ( & micro;2 -OH)2 ( & micro;3 -OH)2 (H2 O)2 ]4 + is interconnected in-plane with H2 dcppa ligands, forming a four-directional extended coordination network that ultimately generates a periodically arranged layered architecture. In [Cu4 (Hdcppa)2 (H2 dcppa)(H2 O)3 ] ( MOF-1 ), there are two types of binuclear copper building blocks, [Cu2 (H2 O)]4 + and [Cu2 (H2 O)2 ]4 + , respectively. The adjacent [Cu2 (H2 O)]4 + units are interconnected via Hdcppa ligands, forming a 1D metal-organic chain. These 1D chains are connected by [Cu2 (H2 O)2 ]4 + to establish a 2D layer, which is further extended by H2 dcppa ligands to a 3D framework. The successful implementation of this synthetic route further validates the feasibility and effectiveness of combining hydrothermal methods with coordination modulation strategies for the targeted construction of functionalized metal-organic crystals. The proton conductivities ( sigma) of CP-1 and MOF-1 were measured under conditions of 85 degrees C and 98 % relative humidity (RH), resulting in values of 2.14 & times; 10-3 and 2.55 & times; 10-2 S/cm, respectively. This study presents a novel approach to fabricating MOFs as proton conductors through coordination modulation strategy. (c) 2026 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Two new organophosphonate-functionalized polyoxomolybdates, H19Na6[(MoV2O4)2(MoO3)2(mu 2-O)5(hedp)3(hedpH)]center dot 6H2O (1) and [C(NH2)3]10[(MoV2O4)4(mu 2-O)2(hpaa)4]center dot 6H2O (2) (where hedpH5 = Etidronic acid, hpaaH4 = Hydroxyphosphonoacetic acid), were successfully synthesized via the modification of the [MoV2O4]2+core with organic phosphonic acid ligands. Systematic research indicates that both complexes exhibit significantly enhanced water adsorption capabilities and markedly improved proton conductivity. Under operating conditions of 50 degrees C and 90 % relative humidity (RH), complex 1 achieves a high proton conductivity of 8.03 x 10-2 S cm-1, while complex 2 reaches 1.64 x 10-3 S cm-1. These findings underscore the substantial potential of these crystalline materials as highly efficient solid-state proton conductors, highlighting their promise for advanced applications such as fuel cells and electrochemical sensors.

To advance the development of next-generation energy storage technology, the pursuit of high energy and power density in energy storage systems has emerged as a critical research goal. High interface resistance impedes the performance of electrochemical energy storage devices, necessitating its optimization to enhance efficiency and stability. In this work, we propose to reduce the interface resistance and accelerate the proton-coupled electron transfer process by constructing a continuous hydrogen bond network between electrodes and electrolytes, thereby enhancing rechargeable supercapacitor performance and establishing a basis for systems that adapt to environmental changes and utilize ambient energy to modulate its performance. Specifically, using PMo10V2-gel and polypyrrole-lignosulfonate (PPy-LS) interpenetrating networks, hydrogen bonding interactions strengthen interfacial contact, ensuring low resistance in the PPL-SC (PMo10V2-PPy-LS rechargeable supercapacitor) and enhancing proton-coupled electron transfer. The rechargeable supercapacitor maintains stable operation and achieves an energy density of up to 111.4 ± 3.4 μWh cm-2 across a wide temperature range (-20 to 60 °C) and varying humidity, demonstrating adaptability to environmental fluctuations. Furthermore, the performance characteristics of the rechargeable supercapacitor are sensitive to ambient conditions, which can modulate its storage efficiency. This study proposes an innovative strategy for creating electrochemical energy storage devices that can adapt to the environment, thereby optimizing efficiency under varying conditions.

Two novel semirigid bis(pyridine)-bis(amide) ligands featuring a pyrazole group as a linker, N,N'-bis(3-picolylamine)-1-hydropyrazole (3-Hdpap), and N,N'-bis(3-pyridinamide)-1-hydropyrazole (3-Hdpyp) were used to combine with polymolybdates (POMos) and a cobalt ion under solvothermal conditions. Four different POMo-based metal-organic complexes (POMoOCs) [Co(3-Hdpap)(β-Mo8O26)0.5(H2O)] (1), [Co(3-H2dpap)(TeMo6O24)0.5(H2O)2] (2), H{Co(3-H2dpap)[AlMo6(OH)5O19](H2O)2} (3), and H2{Co(3-Hdpyp)[CrMo6(OH)5O19](H2O)2}·2H2O (4) were obtained and structurally characterized by single-crystal X-ray diffraction, infrared spectroscopy, and powder X-ray diffraction. Various metal-organic windmill configurations can be observed in the title complexes due to different POMos and ligands, finally resulting in diverse POMo-based architectures, including a two-dimensional (2D) network (1), one-dimensional (1D) supramolecular chains (2-3), and a 2D supramolecular network (4). The electrochemical performances of four complexes were studied in the three-electrode system with their corresponding modified electrodes. At the current density of 1 A·g-1, the specific capacitance values for the glassy carbon electrode modified by 1-4 were recorded as 1658.3, 1026.5, 647.8, and 832.2 F·g-1, respectively. 1-GCE exhibits the best pseudocapacitive activity and is superior to most reported polyoxometalate-based complexes. After 1000 cycles, its capacitance retention rate reaches 89%. Furthermore, the carbon paste electrode bulk-modified by complex 1 serves as an electrochemical sensor for the detection of Cr(VI) and exhibits a low detection limit.

Three new polyoxomolybdate-based complexes functionalized with organic carboxylic acid ligands were synthesized and structurally characterized: Na2[CN3H6]4[(MoV2O4)2(MoVIO4)2(HC3O5)2(H2O)3]·2H2O (complex 1); [CN3H6]6[(MoV2O4)2(MoVIO4)2(HC3O5)2] (complex 2); and [CN3H6]4[(MoV2O4)2(H2C4O6)2]·2H2O (complex 3). Complexes 1-3 were obtained via condensation reactions between the organic carboxylic acid ligands and the [Mo2O4(H2O)6]2+ precursor. Each complex features [Mo2O4(H2O)6]2+ cores, organic carboxylate moieties, and protonated guanidiniums ([CN3H6]+) as structural components. Notably, complexes 1-3 exhibit extensive hydrogen-bonding networks, contributing to their remarkable proton conductivity. Under the conditions of 50 °C and 90% relative humidity, complexes 1-3 demonstrated proton conductivities of 3.52 × 10-2, 9.78 × 10-4, and 1.87 × 10-2 S cm-1, respectively. Furthermore, molecular electrostatic potential (MEP) analysis revealed the surface charge distribution of the polyoxometalate (POM) anion clusters. Combined with single-crystal X-ray diffraction studies, these analyses elucidated potential proton transfer sites and the conduction pathway.

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.

To achieve high electrochemical performance of polyoxometalates (POMs)-based materials, introducing POMs to crystalline supramolecular structures via hydrogen bonding interactions represents a potential strategy. Herein, a new semi-rigid pyrazole-amide-derived bis(pyridyl) ligand N,N'-bis(3-pyridinamide)-1-hydropyrazole (3-Hdpyp) was designed due to the abundant hydrogen bond sites of amide group, as well as the multiple N-donor sites, which was used to assemble with the Keggin-type [PMo12O40]3-(PMo12) anion and cobalt under solvothermal condition. A new 2D sandwich-like supramolecular network [Co2(3-dpyp)2(H2O)2][HPMo12O40] (1) was syn-thesized and structurally characterized. The PMo12 anions are fixed between the 1D metal-organic chains [Co2(3-dpyp)2(H2O)2]nn+ via hydrogen bonding interaction. Complex 1 shows excellent specific capacitances 1062.5F g-1 at the current density of 1 A g-1. After 1000 cycles, it can maintain 90.0% of the capacitance retention. Meanwhile, complex 1 represents an excellent amperometric sensor for measurement of Cr(VI) with low detection limit of 0.22 mu M. The excellent electrochemical performance can be attributed the discrete 2D sandwich-like structures, which can improve the active area of POMs and conductivity of the network.

6-Nitrobenzimidazole ligand was first introduced into polyoxometalate-based metal–organic architecture, and two unique butterfly-like complexes were obtained. Their applications in electrochemical energy storage and electrocatalysis were studied.

By employing a new semi-rigid pyrazole-amide-derived bis(pyridyl) ligand [N,N'-bis(4-picolylamine)-1-hydropyrazole (4-dpap)], a new homopolymolybdate-based two-dimensional (2D) plate-like complex [Co(4-dpap)(H2O)(β-Mo8O26)1/2] (1) has been prepared under solvothermal condition and structurally characterized. The β-Mo8 anions are fixed between the 2D metal–organic networks [Co(4-dpap)(H2O)]n2n+ via hydrogen-bonding interaction. Complex 1 possesses satisfactory specific capacitance of 1512.4 F·g−1 (current density: 1 A·g−1) and good cycling stability (90.8

The research progress on polyoxometalate-based metal–organic complexes and their derivatives as electrocatalysts in sustainable and clean energy conversion applications in aqueous systems is summarized.

Two polymolybdate-based Zn(ii) complexes were constructed from a new bis-pyridine-bis-amide ligand, which can be used as electrocatalysts and electrochemical sensors for Cr(vi), KBrO3, H2O2 and AA, and exhibit selective adsorption of CV and MB.

A new Anderson-type polyoxometalate(POM)-based one-dimensional metal-organic complex, namely, H-2[Cu-2[AlMo6(OH)(6)O-18](2)(3-bpah)(4)(H2O)(4)] . 6H(2)O (1) (3-bpah=N-N '-bis(3-pyridinecarboxamide)-1,2-cyclohexane) was synthesized by hydrothermal method. Implement basic characterization operations of single crystal X-ray diffraction, IR spectroscopy, X-ray powder diffraction and thermogravimetric analysis were performed. Complex 1 possesses not only the typical electrochemical behavior of the Anderson-type polyoxoanion, but also excellent electrochemical stability. The carbon paste electrode bulk modified by complex 1(1-CPE) can be used as an ampere sensor to detect potassium nitrite. The carbon cloth-based electrode fabricated by complex 1(1-CC)was capable of being used as electrocatalyst for hydrogen evolution reaction, the overpotential is 480 mV at the current density of 10 mA cm(-2). 1-CC can also be used as capacitor electrode, which shows an area capacitance of 293 mF cm(-2) in 0.1 M H2SO4 solution and up to 10 hours of life stability. It can maintain 89.7 % of the capacitance after 1000 cycles of constant current charge/discharge.

In this work, aiming for constructing multinuclear metal cluster-modified polymolybdate-based architectures with novel conformation, the "tree"-like multidentate ligand 5-(3-pyridyl)-1H-tetrazole) (3-ptzH) is introduced into the polymolybdate reaction system. Three new polymolybdate-based architectures with various multinuclear metal clusters, H4[Cu6(μ3-OH)2(3-ptz)6(γ-Mo8O28) (H2O)2]·2H2O (BOHU-1), H2[Ag4(3-ptz)2(Mo8O26)] (BOHU-2), and H4[Cu5(3-ptzH)2(3-ptz)2(MnMo9O32)2(H2O)4] (BOHU-3) (BOHU = Bohai University), have been prepared via the hydrothermal method and structurally characterized. In BOHU-1, a kind of pentanuclear copper cluster unit: [Cu5(μ3-OH)2(3-ptz)6]2+ is formed, which connects to construct a one-dimensional (1D) cluster-based chain. The 1D chains are extended to a two-dimensional (2D) layer via the Cu ions, which are further linked by the 4-connected [γ-Mo8O28]8- anions to build a three-dimensional (3D) framework. In BOHU-2, when a AgI ion was used as the central metal, the 3-ptz adopts different coordination modes to link the Ag ions, forming hexanuclear [Ag6(3-ptz)4]2+ cluster and finally 1D chains. These 1D cluster-based chains are connected by the 6-connected [γ-Mo8O26]4- anions to establish a 2D layer, which is further extended by [Mo8O26]n4n- 1D chains to a 3D framework. For BOHU-3, the chiral [MnMo9O32]6- anions are introduced and coordinated with the Cu ions to build left- and right-handed 1D chains, which are connected via the [Cu3(3-ptz)4]2+ cluster to form a 1D ladder-like chain. The effects of 3-ptz on the formation of multinuclear clusters, as well as the metals and polymolybdates on the multinuclear clusters and final structures of BOHU-1∼3, are discussed. The electrochemical performances of BOHU-1∼3 as electrode materials for supercapacitors and electrochemical sensors are investigated.

Two new Anderson-type polyoxometalate (POM)-based metal-organic complexes, namely: H[Cd(L) (CrMo6(OH)(6)O-18)].2H(2)O (1) and H[Co(L)(CrMo6(OH)(6)O-18)(H2O)(2)].3H(2)O (2) (L = N, N'-bis(3-pyridinecarbox-amide)-1,4 cyclohexane) have been successfully synthesized under hydrothermal condition and characterized in detail. For 1, the [CrMo6(OH)(6)O-18](3)-anion adopts hexadentate coordination pattern connecting with binuclear Cd-2(II) unit to form a two-dimensional (2D) layer, which is further expanded into a three-dimensional framework by the L ligands. In 2, The CrMo6 anions exhibit tetradentate coordination mode to connect the metal ions constructing a 2D layer. The L ligand does not play a linkage role and only suspend on the 2D network, which is different from complex 1. The influence of central metal ions on the architectures was discussed. The electro-catalytic reduction of potassium bromate and the electrocatalytic oxidation of ascorbic acid by complexes 1 and 2 were investigated. These title complexes could be regarded as amperometric sensors for the detection of potassium bromate and ascorbic acid. In particular, complex 1 shows the lowest detection limit for these two substances, suggesting its better electrochemical performance.

In this paper, a kind of electrochemical sensing material with tunable activity and high stability is fabricated from polymolybdate-based metal-organic complex. The polymolybdate-based metal-organic complex: H2Ni (nppa)2(H2O)2[gamma-Mo8O26] (1) is synthesized by introducing a flexible pyrazine-pyridine ligand containing amine groups: N-(pyridin-3-yl)pyrazin-2-amine (nppa) under hydrothermal condition. Complex 1 exhibit 1D chain structure based on polyoxoanions and metal ions. The nppa ligands are decorated on the 1D chain in mono -dentate fashion. Bulk-modified carbon paste electrode (CPE) fabricated by the title complex is used as the working electrode for electrochemically sensing inorganic and organic molecules in aqueous systems. 1-CPE displays electrochemical sensing activity towards BrO3- and ascorbic acid (AA) with low detection limits of 1.22 and 0.76 mu M, respectively. Meanwhile, 1-CPE can achieve tunable electrochemical sensing performance, relying on different catalytic activity of reduction products corresponding to multi-step redox reactions. Additionally, its electrochemical activity can be retained under different acid environment.

In this paper, three new polyoxometalates (POM)-based metal-organic complexes constructed from a new semi-rigid organic ligand N,N'-bis(4-pyrimidinecarboxamido)-1,2-cyclohexane (4-bpmah) H-2[Cu(4-bPrnah)(2)(SiMo12O40)(H2O)(2)]center dot 2H(2)O (1), H[cu(4-bpmah)(2)(PMo12O40(H2O)(2)]center dot 2H(2)O (2) and [Cu(4-bpmah)(H2O)(2)[Cu-2(TeMo6O24 )(H2O)(10)center dot 4H(2)O (3) were synthesized by hydrothermal method. Single crystal X-ray analyses showed that complexes 1 and 2 were isostructural, in which the isolated Keggin-type [SiMo12O40](4-)/[PMo12O40](3-) anions and [Cu(4-bpmah)(2)(H2O)(2)](2n+) units were expanded into 3D supramolecular structures through hydrogen bond interactions. In complex 3, the 1D [Cu(4-bpmah)(H2O)(2)](2n+) metal-organic chains and isolated [Cu-2(TeMo6O24)(H2O)(10)](2n-) units were expanded into a 3D supramolecular framework by the hydrogen bond interactions. In this paper, carbon cloth working electrodes composited by the title complexes (1/CC, 2/CC and 3/CC) were prepared and used as electrodes for supercapacitors. The performance of supercapacitors as well as the influence of electrolyte solution and title complexes quality load on the performance of supercapacitors were studied. Furthermore, the electrochemistry and electrocatalytic behaviors of complexes 1-3 bulk-modified carbon paste electrodes (1-CPE, 2-CPE and 3-CPE) toward the reduction of KBrO3, KNO2, Cr(VI), as well as their sensing behaviors on Cr(VI) were investigated. (C) 2022 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.