Proteoglycan inhibition of canonical BMP-dependent cartilage maturation delays endochondral ossification.

During endochondral ossification, chondrocytes secrete a proteoglycan (PG)-rich extracellular matrix that can inhibit the process of cartilage maturation, including expression of Ihh and Col10a1. Because bone morphogenetic proteins (BMPs) can promote cartilage maturation, we hypothesized that cartilage PGs normally inhibit BMP signalling. Accordingly, BMP signalling was evaluated in chondrocytes of wild-type and PG mutant (fam20b-/-) zebrafish and inhibited with temporal control using the drug DMH1 or an inducible dominant-negative BMP receptor transgene (dnBMPR). Compared with wild type, phospho-Smad1/5/9, but not phospho-p38, was increased in fam20b-/- chondrocytes, but only after they secreted PGs. Phospho-Smad1/5/9 was decreased in DMH1-treated or dnBMPR-activated wild-type chondrocytes, and DMH1 also decreased phospho-p38 levels. ihha and col10a1a were decreased in DMH1-treated or dnBMPR-activated chondrocytes, and less perichondral bone formed. Finally, early ihha and col10a1a expression and early perichondral bone formation of fam20b mutants were rescued with DMH1 treatment or dnBMPR activation. Therefore, PG inhibition of canonical BMP-dependent cartilage maturation delays endochondral ossification, and these results offer hope for the development of growth factor therapies for skeletal defects of PG diseases.

Dynamics of Linkers in Metal-Organic Framework Glasses.

Metal-organic framework (MOF) glasses have emerged as a new class of organic-inorganic hybrid glass materials. Considerable efforts have been devoted to unraveling the macroscopic dynamics of MOF glasses by studying their rheological behavior; however, their microscopic dynamics remain unclear. In this work, we studied the effect of vitrification on linker dynamics in ZIF-62 by solid-state 2H nuclear magnetic resonance (NMR) spectroscopy. 2H NMR relaxation analysis provided a detailed picture of the mobility of the ZIF-62 linkers, including local restricted librations and a large-amplitude twist; these details were verified by molecular dynamics. A comparison of ZIF-62 crystals and glasses revealed that vitrification does not drastically affect the fast individual flipping motions with large-amplitude twists, whereas it facilitates slow cooperative large-amplitude twist motions with a decrease in the activation barrier. These observations support the findings of previous studies, indicating that glassy ZIF-62 retains permanent porosity and that short-range disorder exists in the alignment of ligands because of distortion of the coordination angle.

Denary High-Entropy Oxide Nanoparticles Synthesized by a Continuous Supercritical Hydrothermal Flow Process.

High-entropy oxide nanoparticles (HEO NPs) have been intensively studied because of their attractive properties, such as high stability and enhanced catalytic activity. In this work, for the first time, denary HEO NPs were successfully synthesized using a continuous supercritical hydrothermal flow process without calcination. Interestingly, this process allows the formation of HEO NPs on the order of seconds at a relatively lower temperature. The synthesized HEO NPs contained 10 metal elements, La, Ca, Sr, Ba, Fe, Mn, Co, Ru, Pd, and Ir, and had a perovskite-type structure. Atomic-resolution high-angle annular dark-field scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy measurements revealed homogeneous dispersion of the 10 metal elements. The obtained HEO NPs also exhibited a higher catalytic activity for the CO oxidation reaction than that of the LaFeO3 NPs.

Electron Localization Induced by Disordered Anions in an Organic Conductor.

We report on a new organic conductor κ″-(ET)2Cu[N(CN)2]Br (κ″-Br), which is the first polymorph of an organic superconductor κ-(ET)2Cu[N(CN)2]Br (κ-Br), where ET denotes bis(ethylenedithio)tetrathiafulvalene. κ″-Br has a similar κ-type arrangement of ET molecules to κ-Br, but, in contrast to the orthorhombic κ-Br, which has ordered polyanion chains, presents a monoclinic crystal structure with disordered polymeric anion chains. To elucidate the electronic state of κ″-Br, we performed band calculations as well as transport, magnetic, and optical measurements. The calculated band dispersion, magnitude of electron correlation, and room-temperature optical conductivity spectra of κ″-Br were comparable to those of κ-Br. Despite these similarities, the κ″-Br salt exhibited a semiconducting behavior. The electron spin resonance and Raman spectroscopies indicated that there is neither magnetic nor charge order in κ″-Br, suggesting the occurrence of Anderson localization due to disordered anion layers.

Systematic study of ionic conduction in silver iodide/mesoporous alumina composites 2: effects of silver bromide doping.

In our preceding paper (Y. Fukui et al., Phys. Chem. Chem. Phys., 2023, 25, 25594-25602), we reported a systematic study of the Ag+-ion conducting behaviour of silver iodide (AgI)-loaded mesoporous aluminas (MPAs) with different pore diameters and AgI-loading ratios. By optimising the control parameters, the Ag+-ion conductivity has reached 7.2 × 10-4 S cm-1 at room temperature, which is more than three orders of magnitude higher than that of bulk AgI. In the present study, the effect of silver bromide (AgBr)-doping in the AgI/MPA composites on Ag+-ion conductivity is systematically investigated for the first time, using variable-temperature powder X-ray diffraction, differential scanning calorimetry, and electrochemical impedance spectroscopy measurements. The AgBr-doped AgI/MPA composites, AgI-AgBr/MPA, formed a homogeneous ß/γ-AgI-structured solid solution (ß/γ-AgIss) for the composites with AgBr ≤ 10 mol%, above which the composites underwent a phase separation into ß/γ-AgIss and face-centred cubic AgBr solid solutions (AgBrss). The onset temperature of the exothermic peaks attributed to the transition from α-AgI-structured solid-solution phase to ß/γ-AgIss or AgBrss decreased with increasing the AgBr-doping ratio. The room-temperature ionic conductivity of the AgI-AgBr/MPA composites exhibited a volcano-type dependence on the AgBr-doping ratio with the highest value (1.6 × 10-3 S cm-1) when the AgBr content was 10 mol%. This value is more than twice as high as that of the highest conducting AgI/MPA found in our previous study.

A Three-Dimensionally Extended Metal-Organic Ladder Compound Exhibiting Proton Conduction.

Ladder systems situated in the dimensional crossover region have attracted much attention because their electronic states and physical properties depend strongly on the electronic correlations among the constituent legs. Generally, two-/three-legged transition metal-oxide ladder compounds are studied as representative ladder systems, but two-/three-dimensional (2D/3D) extensions based on such ladder systems with a few numbers of legs are difficult because of the extreme synthesis conditions. Here, for the first time, we report the successful creation of a 3D extended two-legged ladder compound, [Pt(en)(dpye)I]2(NO3)4 ⋅ 2H2O (en=ethylenediamine; dpye=1,2-Di(4-pyridyl)ethane), which is obtained by simple oxidative polymerization of a small Pt macrocyclic complex using elemental I2. The unique 3D extended lattice consists of 1D mixed-valence halogen-bridged metal chains (⋅⋅⋅Pt-I-Pt-I⋅⋅⋅) and helically arranged macrocyclic units as the constituent legs and rungs, as confirmed by single-crystal X-ray diffraction. Diffuse X-ray scattering analyses and optical measurements revealed that the out-of-phase mixed-valence Pt2+/Pt4+ arrangement arises from the weak interchain correlation among adjacent legs. In addition, this compound shows an increase in proton conductivity by a factor of up to 1000, depending on humidity.

Self-Assembled Crystalline Bundles in Soluble Metal-Organic Nanotubes.

The use of nanotubes in the solution state is crucial not only for the exploration of physical and chemical behaviors at the molecular level but also for application such as thin-film fabrication. Surface modification is generally used to solubilize carbon nanotubes (CNTs) and various synthetic nanotubes; however, this method may affect the surface properties of the original nanotubes, and the detailed crystal structure obtained after modification is unclear. Here, we report the synthesis of a crystalline and soluble metal-organic nanotube consisting of a cationic tubular framework and an anion with a long alkyl chain. The nanotubular structures are formed not only in the solid state but also in the solution state, as confirmed by an X-ray structural analysis, optical measurements, and electron microscopy studies. This nanotube system is realized in different states without any surface modification, which is quite different from typical CNTs and synthetic nanotubes. In addition, self-assembled crystalline bundles are directly observed using transmission electron microscopy (TEM) for the first time in a metal-organic nanotube system. The bundle structures are also confirmed by atomic force microscopy (AFM) observations of thin nanotube films. We envisage a systematic design of such soluble metal-organic nanotubes that will enable direct observation of mass transport behavior in channels of bundles or a single nanotube, as well as a wide range of thin-film applications.

Continuous-Flow Chemical Synthesis for Sub-2 nm Ultra-Multielement Alloy Nanoparticles Consisting of Group IV to XV Elements.

Multielement alloy nanoparticles have attracted much attention due to their attractive catalytic properties derived from the multiple interactions of adjacent multielement atoms. However, mixing multiple elements in ultrasmall nanoparticles from a wide range of elements on the periodic table is still challenging because the elements have different properties and miscibility. Herein, we developed a benchtop 4-way flow reactor for chemical synthesis of ultra-multielement alloy (UMEA) nanoparticles composed of d-block and p-block elements. BiCoCuFeGaInIrNiPdPtRhRuSbSnTi 15-element alloy nanoparticles composed of group IV to XV elements were synthesized by sequential injection of metal precursors using the reactor. This methodology realized the formation of UMEA nanoparticles at low temperature (66 °C), resulting in a 1.9 nm ultrasmall average particle size. The UMEA nanoparticles have high durability and activity for electrochemical alcohol oxidation reactions and high tolerance to CO poisoning. These results suggest that the multiple interactions of UMEA efficiently promote the multistep alcohol oxidation reaction.

Molybdenum-Ruthenium-Carbon Solid-Solution Alloy Nanoparticles: Can They Be Pseudo-Technetium Carbide?

Technetium (Tc), atomic number 43, is an element that humans cannot freely use even in the 21st century because Tc is radioactive and has no stable isotope. In this report, we present molybdenum-ruthenium-carbon solid-solution alloy (MoxRu1-xCy) nanoparticles (NPs) that are expected to have an electronic structure similar to that of technetium carbide (TcCy). MoxRu1-xCy NPs were synthesized by annealing under a helium/hydrogen atmosphere following thermal decomposition of metal precursors. The obtained NPs had a solid-solution structure in the whole composition range. MoxRu1-xCy with a cubic structure (down to 30 atom % Mo in the metal ratio) showed a superconducting state, and the transition temperature (Tc) increased with increasing Mo composition. The continuous change in Tc across that of TcCy indicates the continuous control of the electronic structure by solid-solution alloying, leading to pseudo-TcCy. Density functional theory calculations indicated that the synthesized Mo0.53Ru0.47C0.41 has a similar electronic structure to TcC0.41.

Influences of amino-terminal modifications on amyloid fibril formation of human serum amyloid A.

Human serum amyloid A (SAA) is a precursor protein involved in AA amyloidosis. The N-terminal region of the SAA molecule is crucial for amyloid fibril formation, and therefore modifications in this region are considered to influence the pathogenesis of AA amyloidosis. In the present study, using the N-terminal peptide corresponding to the putative first helix region of the SAA molecule, we investigated the influences of N-terminal modifications on amyloid fibril formation. Spectroscopic analyses revealed that carbamoylation of the N-terminal amino group delayed the onset of amyloid fibril formation. From transmission electron microscopic observations, the N-terminal carbamoylated aggregate showed remarkably different morphologies from the unmodified control. In contrast, acetylation of the N-terminal amino group or truncation of N-terminal amino acid(s) considerably diminished amyloidogenic properties. Furthermore, we also tested the cell toxicity of each peptide aggregate on cultured cells by two cytotoxic assays. Irrespective of carbamoylation or acetylation, MTT assay revealed that SAA peptides reduced the reductive activity of MTT on cells, whereas no apparent increase in LDH release was observed during an LDH assay. In contrast, N-terminal truncation did not affect either MTT reduction or LDH release. These results suggest that N-terminal modification of SAA molecules can act as a switch to regulate susceptibility to AA amyloidosis.

Isomerization-Controlled Proton-Electron Coupling in a π-Planar Metal Complex.

Proton-coupled electron transfer (PCET) is a ubiquitous and fundamental process in biochemistry and electrochemistry performed by transition-metal complexes. Most synthetic efforts have been devoted to selecting the components, that is, metal ions and ligands, to control the proton-electron coupling. Here, we show the first example of controlling the proton-electron coupling using the cis-trans metal-ligand isomerization in a π-planar platinum complex, Pt(itsq)2 (itsq1-: o-iminothiosemiquinonate). Both the isomers, which were obtained separately, were characterized by single-crystal X-ray diffraction, and the cis-to-trans isomerization was achieved by immersing in organic solvents. Theoretical calculations predicted that the proton-electron coupling evaluated from the energetic stabilization of the lowest unoccupied molecular orbital by protonation varies greatly depending on the geometrical configuration compared to the metal substitution.

Synthesis, X-ray Structures, and Optical and Magnetic Properties of Cu(II) Octafluoro-octakisperfluoro(isopropyl)phthalocyanine: The Effects of Electron Addition and Fluorine Accretion.

The stepwise reduction of copper(II) 1,4,8,11,15,18,22,25-octafluoro-2,3,9,10,16,17,23,24-octakisperfluoro(isopropyl) phthalocyanine (CuIIF64Pc) in o-dichlorobenzene (C6H4Cl2) by potassium graphite in the presence of cryptand(K+), abbreviated L+, results in the formation of (L+)[CuII(F64Pc•3-)]-·2C6H4Cl2 (1), (L+)2[CuII(F64Pc4-)]2-·C6H4Cl2 (2), and (L+)2[CuII(F64Pc4-)]2- (3) complexes. Single-crystal X-ray structures revealed their composition and a monotonic increase with increased phthalocyanine (Pc) negative charges of the magnitude of alternative shortening and elongation of the prior equivalent Nmeso-C bonds. The complexes are separated by bulky i-C3F7 substituents, large cryptand counterions, and solvent molecules. Weak, new bands are generated in the visible and near-infrared (NIR) domains upon reductions. The one-electron reduced complex, [CuII(F64Pc•3-)]-, is a diradical, exhibiting broad electron paramagnetic resonance (EPR) signals, with intermediate parameters between those typical to CuII and F64Pc•3-. The two-electron reduced complexes, [CuII(F64Pc4-)]2-, contain a diamagnetic F64Pc4- macrocycle and a single spin, S = 1/2, on CuII. The bulky perfluoroisopropyl groups are suppressing intermolecular π-π interactions between Pcs in the [CuII(F64Pcn-)](n-2)- (n = 3, 4) anions, 1-3, similar to the case of the nonreduced complex. However, π-π interactions between 1 and o-dichlorobenzene are observed. The d9 and Pc electrons in 1 are antiferromagnetically coupled, J = -0.56 cm-1, as revealed by superconducting quantum interference device (SQUID) magnetometry, but the coupling is at least 1 order of magnitude smaller compared with the coupling observed for CuII(F8Pc•3-) and CuII(F16Pc•3-), a testimony to the F accretion effect of rendering the Pc macrocycle progressively more electron-deficient. The data for CuII(F64Pc) provide structural, spectroscopic, and magnetochemical insights, which establish a trend of the effects of fluorine and charge variations of fluorinated Pcs within the macrocycle series CuII(FxPc), x = 8, 16, 64. Diamagnetic Pcs might be useful for photodynamic therapy (PDT) and related biomedical applications, while the solvent-processable biradicalic nature of the monoanion salts may constitute the basis for designing robust, air-stable electronic, and magnetically condensed materials.

Paramagnetic {[Fe(CO)2]2-µ2-η2:η2-η2:η2-(C60)2}2- Dimer Bridged by Iron Atoms and C-C Bonds: Effect of Starting Iron Carbonyls on Structures and Properties of Negatively Charged Iron-Bridged Fullerene Dimers.

The reaction between an excess of Fe(CO)5 with {Cryptand(K+)}(C60•-) produced the salt {Cryptand(K+)}2{[Fe(CO)2]2-µ2-η2:η2-η2:η2-(C60)2}2-·4C6H4Cl2 (1) containing negatively charged iron-bridged fullerene dimers. In these dimers, the C60 cages are linked via two Fe(CO)2 fragments, forming short Fe-C(C60) bonds with a length of 2.070(3) Å and via two intercage C-C bonds with a length of 1.566(3) Å. Interfullerene center-to-center distance is short, being 9.02 Å. Thus, the coordination-induced dimerization of fullerenes is observed in 1. The dimer is negatively charged, with additional negative electron density mainly localized on iron atoms and, to a lesser extent, on the C60 cages, as revealed by optical and electron paramagnetic resonance spectra. These dimers have a diamagnetic singlet ground state with a small singlet-triplet gap of 25 K; consequently, they transfer to a paramagnetic state with two S = 1/2 spins per dimer above 50 K. Previously, different dimers with isomeric structures were obtained starting from {Cryptand(K+)}(C60•-) and Fe3(CO)12. However, these dimers exhibit diamagnetic properties, owing to the formation of a Fe-Fe bond. In contrast, in dimer 1, the Fe atoms are positioned too far apart to form such a bond, preserving the spin on Fe. We assume that both dimers are formed through the same [Fe(CO)3](C60•-) intermediate, but the subsequent interaction of this intermediate with Fe3(CO)12 or its dimerization yields different dimers. Therefore, the starting carbonyls can control the structures and properties of the resulting dimers.

Synthesis of biotinylated chondroitin sulfate DA and AD tetrasaccharides composed of hetero-type disaccharide units, and their interactions with the mAb MO-225.

Chondroitin sulfate (CS), a linear acidic polysaccharide, exhibits numerous biological activities that are dependent on sulfation patterns. CS oligosaccharides comprise repeating disaccharide units with different (hetero)-type sulfation patterns and are common in nature. We herein report the synthesis of the following biotinylated CS tetrasaccharides: CS-AD [ßGalNAc4S(1-4)ßGlcA(1-3)ßGalNAc6S(1-4)ßGlcA2S] and CS-DA [ßGalNAc6S(1-4)ßGlcA2S(1-3)ßGalNAc4S(1-4)ßGlcA], in a stereo-controlled manner. We also demonstrated that the CS-d-specific monoclonal antibody MO-225 bound more strongly to CS-DA than to CS-DD or -AD.

A prospective randomized study of multimodal analgesia combined with single injection transversus abdominis plane block versus epidural analgesia against postoperative pain after laparoscopic colon cancer surgery.

PURPOSE: Transversus abdominis plane (TAP) block is a safe, effective, and promising analgesic procedure, but TAP block only cannot overcome postoperative pain. We conducted a prospective randomized study to evaluate postoperative pain control using multimodal analgesia (MA) combined with a single injection TAP block compared with epidural analgesia (EA) after laparoscopic colon cancer surgery. METHODS: Sixty-seven patients scheduled for elective laparoscopic colon cancer surgery were enrolled in this study and randomized into EA and MA groups. The primary endpoint was the frequency of additional analgesic use until postoperative day (POD) 2. The VAS score, blood pressure, time to bowel movement, time to mobilization, postoperative complications, and length of hospital stay were also compared between the two groups. RESULTS: Sixty-four patients (EA group, n = 33; MA group, n = 31) were analyzed. The patient characteristics did not differ markedly between the two groups. The frequency of additional analgesic use was significantly lower in the MA group than in the EA group (P < 0.001), whereas the VAS score did not differ markedly between the two groups. The postoperative blood pressure on the day of surgery was significantly lower in the MA group than in the EA group (P = 0.016), whereas urinary retention was significantly higher in the EA group than in the MA group (P < 0.001). CONCLUSION: MA combined with a single injection TAP block after laparoscopic colon cancer surgery may be comparable to EA in terms of analgesia and superior to EA in terms of urinary retention.

Systematic study of ionic conduction in silver iodide/mesoporous alumina composites 1: effects of pore size and filling level.

A systematic study of Ag+-ion conducting behavior in Ag+-loaded porous materials was conducted over the entire sub-10 nm region for the first time. The effects of the pore diameter of mesoporous aluminas (MPAs) and the amount of silver iodide (AgI) loaded into MPAs were investigated using N2 gas adsorption/desorption, powder X-ray diffraction, differential scanning calorimetry, and electrochemical impedance spectroscopy measurements. Confinement of AgI in the mesoporous space lowers the phase transition temperature between the ß/γ- and α-phases relative to that of bulk AgI. The AgI-loading into the MPAs with smaller pores led to a more significant decrease in the transition temperature, possibly because the smaller AgI nanoparticles in the pores must have a higher surface energy to stabilize the high-temperature phase. The room-temperature ionic conductivity exhibits a volcano-type dependence on the pore diameter with the highest value when AgI was loaded into MPA with a pore diameter of 7.1 nm (7.2 × 10-4 S cm-1 at room temperature). Concerning the 7.1 nm-MPA, the room-temperature ionic conductivity was the highest for the nearly fully occupied composite, which is more than three orders of magnitude higher than that of the bulk AgI. The present study reveals that the Ag+-ion conductivity in AgI/MPA composites can be controlled by optimizing the pore diameter of MPA and the AgI-loading ratio.

Intra-soft tissue and intramedullary antibiotic perfusion in combination with negative pressure wound therapy.

OBJECTIVE: Intra-soft tissue and intramedullary antibiotic perfusion (iSAP and iMAP), which combine continuous administration of antibiotic solution to the wound and negative pressure wound therapy (NPWT), have been reported to be a useful management approach for hard-to-heal ulcers in the field of orthopaedic surgery. We report the efficacy of this treatment and discuss the key points. METHOD: The recipients of this treatment had contaminated fresh severe trauma with a high risk of infection, or hard-to-heal ulcers which were expected to be difficult to manage with conventional NPWT alone. Continuous administration of 1200µg/ml of gentamicin (GM) solution to the wound was performed along with NPWT. The GM solution was administered subcutaneously using a small catheter for iSAP, while intramedullary administration used a bone marrow needle for iMAP. RESULTS: iSAP was employed in all 10 patients who took part, and iMAP in three of these patients. The average treatment time was 13.6 days with iSAP and 9.3 days with iMAP. The mean serum GM level during the therapy was 1.02µg/ml. Moderate GM-induced acute kidney injury was suspected in one case, but resolved spontaneously after GM administration was stopped. Favourable wound bed preparation was achieved in all cases without recurrence of infection. CONCLUSION: Combination with continuous suction by NPWT is able to keep the local concentration of antibiotic above the minimum inhibitory concentration of biofilm-coated bacteria within the wound. We have referred to this treatment as continuous local antibiotic perfusion. Further investigation of local pharmacodynamics in the wound and side-effects of this treatment are warranted.

A Significant Two-Dimensional Structural Transformation in a Coordination Polymer that Changes Its Electronic and Protonic Behavior.

A 2D-to-2D (2D: two-dimensional) structural transformation accompanying significant bond rearrangement and coordination environment change is demonstrated in a coordination polymer (CP) comprised of copper(II) ions and terephthalate (BDC2- ) ligands for the first time. When immersed in water, a free-standing membrane of 2D Cu(BDC)(DMF) (Cu-1; DMF: N,N-dimethylformamide) transforms into 2D Cu(BDC)(H2 O)2 (Cu-2) while maintaining its highly oriented layered structure. In the 2D sheet, paddlewheel-type CuII dimers coordinated with four bidentate BDC ligands in a square-planar array in Cu-1 were released to form uniform aqua-bridged CuII chains, which are cross-linked with each other by unidentate BDC ligands, in Cu-2. The present facile approach to implement the 2D-to-2D transformation accompanied by bond rearrangement, which is characteristic of CPs, leads to a marked increase in in-plane magnetic susceptibility and proton conductivity. In situ experiments in support of theoretical calculations unveiled the energy diagram that governs the unique structural transformation.

Robust Proton Conduction against Mechanical Stress in Flexible Free-Standing Membrane Composed of Two-Dimensional Coordination Polymer.

Introduction of mechanical flexibility into proton-conducting coordination polymers (CPs) is in high demand for future protonic applications such as fuel cells and hydrogen sensors. Although such mechanical properties have been primarily investigated in one-dimensional (1D) CPs, in this study, we successfully fabricated highly flexible free-standing CP membranes with a high surface-to-volume ratio, which is beneficial for enhanced performance in the aforementioned applications. We fabricated a layered CP, Cu2 (NiTCPP) (H4 (H2 TCPP); 5,10,15,20-tetrakis(4-carboxyphenyl) porphyrin), in which a two-dimensional (2D) square grid sheet composed of tetradentate nickel porphyrins and paddlewheel-type copper dimers was connected to each other by weak van der Waals forces. The mechanical flexibility was evaluated by bending and tensile tests. The flexural and Young's moduli of the membrane were significantly higher than those of conventional Nafion membranes. Electrochemical impedance spectroscopy analysis revealed that the in-plane proton conductivity of the membrane was maintained even under applied bending stress. Because the X-ray diffraction analysis indicates that the proton-conducting pathway through the hydrogen bonding network remains intact during the bending operation, our present study provides a promising strategy for the fabrication of new and advanced 2D CPs without using substrates or additional polymers for protonic devices.

Cooperative Proton and Li-ion Conduction in a 2D-Layered MOF via Mechanical Insertion of Lithium Halides.

Ionic conduction in highly designable and porous metal-organic frameworks has been explored through the introduction of various ionic species (H+ , OH- , Li+ , etc.) using post-synthetic modification such as acid, salt, or ionic liquid incorporation. Here, we report on high ionic conductivity (σ>10-2  S cm-1 ) in a two-dimensionally (2D)-layered Ti-dobdc (Ti2 (Hdobdc)2 (H2 dobdc), H4 dobdc: 2,5-dihydroxyterephthalic acid) via LiX (X=Cl, Br, I) intercalation using mechanical mixing. The anionic species in lithium halide strongly affect the ionic conductivity and durability of conductivity. Solid-state pulsed-field gradient nuclear magnetic resonance (PFG NMR ) verified the high mobility of H+ and Li+ ions in the temperature range of 300-400 K. In particular, the insertion of Li salts improved the H+ mobility above 373 K owing to strong binding with H2 O. Furthermore, the continuous increase in Li+ mobility with temperature contributed to the retention of the overall high ionic conductivity at high temperatures.