The efficiency of Electrochemical Water Splitting can be improved using chiral catalysts and the Chiral Induced Spin Selectivity (CISS) effect. The spin polarized currents generated by CISS favour the formation of O 2 in its triplet ground state and lower the overpotential required to drive the Oxygen Evolution Reaction (OER). However, systematic studies in classes of closely related materials are lacking. Here, we investigate three pairs of nickel(II) coordination polymers based on 1,4-benzenedicarboxylate ligands with either chiral or achiral alkoxy side chains and three different degrees of crystallinity. The most crystalline materials are authenticated as 2D Metal-Organic Frameworks (MOFs) with a layered structure and hexanickel(II) metallacrown subunits. These noble metal-free compounds serve as efficient catalysts of OER, with current densities that compete with or even largely surpass that of state-of-the-art IrO 2 . All chiral materials show asymmetric spin polarization and improved catalytic activity compared to their achiral counterparts. Crystallinity is found to largely enhance the effect of chirality, although the most crystalline MOF samples retain only ~25% of intact alkoxy groups. Our results establish a correlation between structure, spin polarization, and chiral catalytic enhancement and prove that structural long-range order is more important than the number of chiral centers.

Nontargeted metabolite profiling prioritizes robust comparisons of the analytical outcomes rather than absolute concentration measurement. In this work, it is shown that a harmonized 1D 1H NMR workflow, originally adopted for nontargeted NMR analysis, can also support reliable quantitative determination of betaine when spectra acquired under profiling-oriented conditions, nonideal for quantification, are anchored to gravimetrically traceable standards and corrected by a suitable factor accounting for bias in absolute concentration estimates. This study presents the results of an interlaboratory comparison designed to investigate the main factors affecting the accuracy and reproducibility of nontargeted 1H NMR data when different spectrometers and operators are involved. The case study focused on the determination of betaine in aqueous extracts of durum wheat (cvs. Marco Aurelio and Iride) and the corresponding pasta products. A common set of samples was analyzed using a harmonized acquisition protocol across 50 spectrometers operating at magnetic field strengths ranging from 80 to 700 MHz. Two data-processing strategies were compared: operator-dependent processing (multiple operators using different software packages) and centralized processing (single operator) performed with five different software platforms. Quantification was carried out by both an internal standard method, using 3-(trimethylsilyl)-2,2,3,3-tetradeutero-propionic acid, sodium salt (TSP-d 4) as a reference, and an external standard method, employing TSP-d 4, dimethyl sulfone (DMSO2), and betaine as references. The results demonstrated that the largest source of variability lies in operator-dependent data-processing choices rather than instrumental characteristics. TSP-d 4 systematically overestimated the betaine concentration and introduced additional variability. By contrast, DMSO2 and betaine provided accurate and highly precise quantification with Horwitz ratios consistently below unity, indicating reproducibility superior to generic interlaboratory expectations. Internal standard method also achieved reproducibility within the accepted 0.5-2.0 HorRat range. Overall, this work shows that spectra acquired for nontargeted metabolite profiling can support quantitative determination of betaine, and potentially of other selected metabolites, provided that the same acquisition and processing protocol is maintained and that appropriate gravimetrically traceable calibration is applied.

The efficiency of Electrochemical Water Splitting (EWS) can be improved exploiting spin-polarized currents produced by chiral materials through the Chiral-Induced Spin Selectivity (CISS) effect. During EWS, electron spin polarization (SP) favours the formation of O 2 in its triplet ground state lowering the overpotential required to drive the Oxygen Evolution Reaction (OER). However, most systems studied so far lack of well-defined structural properties. In this work, a family of nickel(II)-based coordination polymers exhibiting low (Ni-L1), intermediate (Ni-L2), and high (Ni-L3) crystallinity were prepared by solvothermal synthesis using 1,4-benzenedicarboxylic acid ligands (H 2 L) functionalized with both achiral (L=A) and chiral (L=C) alkoxy side chains. Ni-L3 are 2D Metal-Organic Frameworks (MOFs) composed by sheets of hexanickel(II) metallacrown subunits. The Ni-C materials show asymmetric SP accompanied by enhanced catalytic activity during OER as compared with their Ni-A counterparts. Moreover, the largest values of SP (~50%) and OER enhancement are observed in the most crystalline samples Ni-C2 and Ni-C3, although these materials and their achiral analogues retain ~40% and ~25% of intact alkoxy groups, respectively. Our work demonstrates that long-range order has a determining role in SP, indicating that chiral MOFs are ideal system to investigate CISS effect through structureproperties correlation studies.

Multichelating ligands with nuclear spin-free donor atoms are of particular interest for creating stable electronic spin qubits based on paramagnetic transition metal ions. We recently focused on the coordinating ability of the bis(β-diketonato) ligand bdhb2-, featuring two "acac" moieties connected through a 1,3-phenylene bridge (H2bdhb = 1,3-bis(3,5-dioxo-1-hexyl)benzene). The two crystalline complexes of bdhb2- so far isolated and structurally characterized, namely [(VO)2(bdhb)2] (1) and [Co2(bdhb)2(py)4] (2), are dimeric and contain bridging bdhb2- ligands; however, they become mononuclear and quasi-macrocyclic in organic solution. To investigate this unique structural isomerism by high-resolution 1H NMR spectroscopy, we have now synthesized a diamagnetic Zn2+ analogue of 1 and 2, namely [Zn2(bdhb)2(py)2] (3). Although both 2 and 3 are dimeric and contain the same ligands, 3 features only one pyridine molecule per metal ion, whose coordination geometry is square pyramidal rather than tetragonally elongated octahedral. The ESI-MS spectra of 3 in THF and CH2Cl2 contain peaks from both monomeric and dimeric species. However, molecular weight determinations by DOSY and conformational studies based on J-coupling analysis and DFT calculations conclusively prove the rearrangement of 3 into quasi-macrocyclic monomers in THF-d8 and CD2Cl2 solution at room temperature.

Oral lichen planus (OLP) is a chronic T-cell-mediated autoimmune disease, with low potential for malignant transformation. Its etiology remains unclear, necessitating immunohistochemical and molecular-level studies to enhance diagnosis and management. Thirteen patients diagnosed with OLP and 13 healthy controls (HCs) were enrolled from three centers. Mucosal tissue samples collected during diagnostic biopsies and unstimulated whole saliva samples were analysed. A comprehensive approach was taken, with high-resolution magic angle spinning (HR-MAS) 1H-NMR spectroscopy performed on biopsies and liquid 1H-NMR spectroscopy on saliva samples to identify potential biomarkers correlated with OLP. Multivariate analyses effectively distinguish OLP patients from HC based on metabolic profiles, with key metabolites contributing to the separation. In tissue, triglycerides were significantly elevated in OLP biopsies, whereas amino acids such as glutamate, glutamine, taurine, glycine and alanine were significantly decreased in OLP tissues compared with controls (p < 0.05). Salivary analysis revealed significant alterations in compounds of bacterial origin-such as isobutyrate, isocaproate, isovalerate and agmatine-suggesting dysbiosis in OLP patients. The metabolic alterations identified highlight the roles of oxidative stress and lipid metabolism in OLP pathogenesis and suggest potential biomarkers for OLP diagnosis. These findings provide new insights into the molecular mechanisms of OLP, which may have important clinical implications for future diagnostic and therapeutic strategies.

Ni and Ni/Fe metal hydroxide organic frameworks (MHOFs) based on aromatic dicarboxylates are attracting great interest as emerging noble metal‐free catalysts for the oxygen evolution reaction (OER), during H 2 production by water splitting. They show good chemical and electrochemical stability during OER, some of them exhibiting similar catalytic activity compared to state‐of‐the‐art catalysts (e.g., IrO 2 ) when isolated as nanosheets. These MHOFs are actually precatalysts and reconstruct into the active NiOOH‐like phases after leaching of the organic linker under electrocatalytic alkaline conditions. Employing β‐Ni(OH) 2 (herein indicated as NiOH‐ x ) with different crystallinity ( x = 1‐low, 2‐intermediate, and 3‐high), we synthesized “bulk” forms of Ni 2 (OH) 2 (L) MHOFs (NiL‐ x ) based on benzene‐1,4‐dicarboxylate (L = BDC 2− ) and azobenzene‐4,4′‐dicarboxylate (L = AZO 2− ) ligands. We systematically obtained highly crystalline NiBDC‐ x and NiAZO‐ x samples, regardless of NiOH‐ x crystallinity. Therefore, the intercalation of L 2− effectively removes stacking faults disorder even from low crystalline NiOH‐1, especially for BDC 2− , while it is less efficient for AZO 2− . The OER‐activities were evaluated after establishing an activation procedure combining cyclic voltammetry with diffuse‐reflectance UV–vis–NIR. NiAZO‐x samples resulted the most stable and efficient catalysts, NiAZO‐1 being the best among them although containing ∼50% in weight of residual NiOH‐1, which converts superficially into highly efficient NiAZO‐phase during synthesis, while retaining its high‐conductivity in the inorganic bulk.

Alkaptonuria (AKU) is a rare metabolic disorder caused by homogentisate 1,2-dioxygenase (HGD) deficiency, leading to homogentisic acid (HGA) accumulation and ochronotic pigment deposition, which drug therapy cannot reverse. The process of pigment formation and deposition is still unclear. This study offers molecular insights into the polymeric structure, with the goal of developing future adjuvant strategies that can inhibit or reverse pigment formation, thereby complementing drug therapy in AKU. HGA polymerisation was examined under physiological, acidic, and alkaline conditions using liquid and solid phase nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), and polyacrylamide gel electrophoresis. At physiological pH, HGA polymerised slowly, while alkaline catalysis accelerated pigment formation while retaining the HGA aromatic scaffold. During the process, EPR detected a semiquinone radical intermediate, consistent with an oxidative coupling mechanism. Reactivity profiling showed the diphenol ring was essential for polymerisation, while -CH2COOH modifications did not impair reactivity. Pigments displayed a polydisperse molecular weight range (11-50 kDa) and a strong negative charge. Solid-state NMR has revealed the presence of phenolic ether and biphenyl linkages. Collectively, these identified structural motifs can serve as a foundation for future molecular targeting related to pigment formation.

Although water is considered detrimental for Li-ion battery technology, a 1% w/w amount of water in a melt of LiCl in ionic liquid 1-butyl-3-methylimidazolium chloride promotes the reduction of lithium into a LiAl intermetallic along with water oxidation to O2 gas. The electrodeposition of an intermetallic layer of several micrometers thickness is demonstrated by combining complementary techniques, such as galvanostatics, X-ray diffraction, electron energy-loss spectroscopy, mass spectrometry, and 1H nuclear magnetic resonance. The concentration of water in the ionic liquid is found to be a critical feature, as no Li is deposited when ionic liquid is dried. Our findings highlight an innovative and simple method to produce a LiAl intermetallic by using water and lithium chloride as chemical reagents.

Skeletal muscles are heterogenous tissues composed of different myofiber types that can be classified as slow oxidative, fast oxidative, and fast glycolytic which are distinguished on the basis of their contractile and metabolic properties. Improving oxidative metabolism in skeletal muscles can prevent metabolic diseases and plays a protective role against muscle wasting in a number of neuromuscular diseases. Therefore, achieving a detailed understanding of the factors that regulate myofiber metabolic properties might provide new therapeutic opportunities for these diseases. Here, we investigated whether peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1) is involved in the control of myofiber metabolic behaviors. Indeed, PIN1 controls glucose and lipid metabolism in a number of tissues, and it is also abundant in adult skeletal muscles; however, its role in the control of energy homeostasis in this tissue is still to be defined. To start clarifying this topic, we compared the metabolome of the tibialis anterior muscle (mainly glycolytic) and soleus muscle (oxidative) in wild-type and Pin1 knockout mice with High-Resolution Magic Angle Spinning (HR-MAS) NMR on intact tissues. Our analysis reveals a clear demarcation between the metabolomes in the two types of muscles and allows us to decode a signature able to discriminate the glycolytic versus oxidative muscle phenotype. We also detected some changes in Pin1-depleted muscles that suggest a role for PIN1 in regulating the metabolic phenotype of skeletal muscles.

Zinc(II)-phenanthroline complexes are widely used as building blocks to prepare solid-phase chiral catalysts. Adsorbing these complexes on montmorillonite – a green solid support with large external and interlayer surfaces – with the possibility of modulating the structure and the immobilization geometry would allow controlling the reactivity towards the substrate. Here, a series of [ZnPhenx]2+ complexes prepared by varying the phenanthroline/Zn2+ molar ratio in solution were adsorbed onto montmorillonite with the aim to grasp relationships between solution composition and the speciation and structure of the adsorbed complexes. The solid samples were characterized by elemental and chemical analysis, X-rays diffraction, thermogravimetric analysis, and NMR measurements. Atomic scale calculations based on Density Functional Theory (DFT) were also performed to define the structuring of the montmorillonite interlayer in the presence of different intercalated [ZnPhenx]2+ complexes. It was found that [ZnPhenx]2+ complexes were intercalated in a fashion which depends on the composition of the starting zinc(II)-phenanthroline solutions, without being its mirror. Properly tuning the phenanthroline/Zn2+ molar ratio in solution, however, the [ZnPhen]2+, [ZnPhen2]2+ and [ZnPhen3]2+ species and their mixtures were immobilized on montmorillonite in a predictable and reproducible way. This has been achieved through a careful control of the immobilization conditions of the complexes and characterization of the resulting materials. The interlayer structure was also characterized with a modelling approach.This work outlines the procedure to obtain the desired catalytic ZnII-montmorillonite hybrid materials useful as nanosized reaction environments from a starting solution containing several different species in equilibrium. This is a valuable tool for obtaining tailored “green” catalysts, as ZnII complexes have been proven to be effective for a wide variety of organic and polymerization reactions.

The kinetics of gelation in the Activators Regenerated by Electron Transfer Atom Transfer Radical Polymerization (ARGET ATRP) of styrene, using a bifunctional initiator and no crosslinking agents are investigated. By applying the method of moments, we develop a system of differential equations that accounts for the formation of polymer rings. The kinetic rate constants of this model are optimized on the experimentally determined kinetics, varying the reaction temperature and ethanol fraction. Subsequently, we explore how variations in the amounts of catalyst, initiator, and reducing agents affect the simulated equilibria of ARGET ATRP, the emergence of gelation, and the swelling properties of the resulting networks. These findings suggest that favoring ring formation enhances the gelation phenomenon, supporting the hypothesis that the networks formed under the reported reaction conditions are olympic gels.

Primary Sjögren's Syndrome (pSS) is a multi-system autoimmune disease that involves the exocrine glands. Lymphocytes infiltrate the gland tissue, leading to anatomical modification and hypofunction. Even if the prognosis of pSS is favorable, quality of life is typically reduced due to the diverse manifestations of the disease. The aim of this study is to compare the salivary metabolomes of pSS with healthy controls (HCs). Seven cases were selected from a cohort of pSS patients, and six age- and sex-matched HCs were recruited from a cohort of volunteers. Whole unstimulated saliva was collected for NMR analysis. Our metabolomic analysis focused on 360 ms total echo 1D 1H NMR CPMG spectra. Metabolites detected with CPMG NMR spectra were assigned through 2D NMR spectra (COSY, TOCSY, and HSQC). About 50 metabolites were detected and assigned. Unsupervised exploratory PCA returned partial clustering, and PLS-DA improved the separation between pSS and HCs, highlighting a pool of metabolites distinctly describing each group. Despite the limited number of samples, the presented preliminary data are promising. PLS-DA indicated well-defined group separation, suggesting that the application of 1H-NMR metabolomics is suitable for the study of pSS.

To sustain Hydrogen Economy, proton exchange membrane (PEM) devices are expected to play a central role in both the generation of clean hydrogen and its efficient employment. Bipolar plates are an essential part of PEM devices, therefore investigations directed to technical improvement and cost reduction of these components deserve considerable attention. This work represents an extension of our previous study on graphite-epoxy composites suitable for manufacturing bipolar plates and based on the use of cheap and commercially available materials. Through appropriate changes in the formulation of the composites and in the processing conditions, we succeeded in obtaining materials with full technical compliance, in terms of electrical conductivity and gas permeability. The processability and productivity of the method were improved as well, through the reduction of molding times. The variation of the properties of the samples with the molding pressure was analyzed.

In this paper, the synthesis and characterization of a new alkoxy benzodithiophene-based small molecule bearing two stereocenters and two end-capping acetyl groups (BDTCOR) are reported. The molecule has been obtained in both enantiopure form (S, S) and stereoisomeric mixture. The spectroscopic properties of BDTCOR in solution were compared to computational data revealing that the molecule is a candidate for optoelectronic applications thanks to a broad UV–Vis absorption spectrum and suitable fluorescence properties. The molecule was deposited as a thin film by physical vapor deposition on SiO2 and PMMA substrates revealing a quite different behavior of the enantiopure form vs. the stereoisomeric mixture. In particular, significant differences were found in film morphology suggesting that, contrary to what observed for the stereoisomeric mixture, enantiopure BDTCOR tends to generate supramolecular well-ordered structures. Moreover, while electronic circular dichroism spectra of enantiopure BDTCOR casted films do not show significant signals, vapor-deposited films show intense Cotton effect, suggesting a synergic role of chirality and of the deposition technique on the molecular order.

The capture of a number of aliphatic (APAs) and heterocyclic (HCAs) amines, known as widespread pollutants, by Cu2+-exchanged montmorillonite (Mt-Cu) was studied through elemental analysis diffuse-reflectance ultraviolet-visible and infra-red spectroscopies, X-rays diffraction, thermal analysis coupled with mass spectrometry of the evolved gases, XANES and EXAFS spectroscopy, and solid-state NMR. The investigated APAs and HCAs were: ethylamine (EtNH2), triethylamine (Et3N), ethylenediamine (En) and morpholine (Morph), piperidine (Piper), and pyridine (Py), respectively. Mt-Cu saturation occurred within 25 h at worst, the immobilized amount was relevant and involved the binding of the amino nitrogen to the interlayer Cu2+ ions. While for APAs the entrapped amount changed with the structure of the molecule, for HCAs it did not. The EXAFS and XANES studies showed that the interlayer Cu2+ ions are strongly coordinated to the amino groups. This resulted in the coordination number changing from four to five coordination, with the exception of En for which the CuII ions remained tetra-coordinated as in pristine Mt-Cu. Residual water molecules were found to be bound to the copper also after exposure to the amines. For EtNH2, En, Morph, and Piper the coordination to CuII occurred without the deprotonation of the amino group. NMR measurements showed the presence of physisorbed amines whose amount depended on the structure: while En was mostly bound to CuII (physisorption was negligible), for EtNH2, Et3N, Morph, and Piper the physisorbed amount ranged from 55 to 30% and for Py it was even the 70%. In addition, En was found to be the amine entrapped with the highest strength and covalent character. The obtained results supported the effectiveness of Cu2+-modified layered silicates as an air/gas purification system. The exploitation of devices based on Cu2+-exchanged montmorillonite could therefore become a very appealing future challenge as the interlayer modification was very simple and fast and the entire process turned out to be green and economic.

Increasing evidence in the field of bioprospection fosters the necessity of studying poorly investigated poisonous marine invertebrates to expand knowledge on animal venom biology. Among marine annelids, amphinomid fireworms are notorious for their bearded trunk equipped with a powerful stinging capacity. Here, a methodological workflow based on analytical chemistry techniques (compound isolation followed by mass spectrometry and spectroscopy analyses) was applied to gain new insights, leading to the identification and structural elucidation of an array of natural products from Mediterranean specimens of Hermodice carunculata. Eight betaine-derived unprecedented compounds, named “carunculines”, were detected, bearing two terminal ammonium groups tri-and disubstituted at the Cα (A, B) and a series of different alkyl chains (I–VIII). The mixture of chemicals was found in all the body parts of H. carunculata, supporting a mechanism of action triggered by their vehiculation inside the dorsal chaetae, and subsequent injection when chaetae break off on contact. Preliminary investigations to understand adaptive features were also performed, showing a trend in carunculine abundance that fits into the evolutionary history of these worms. These findings shed light on the chemical ecology of amphinomids, giving reasons for the success of H. carunculata in benthic environments and providing promising novel metabolites for biotechnological implications.

Bipolar plates (BPs) are important components of Proton Exchange Membrane Fuel Cells (PEMFC). Graphite-epoxy composites, having a better corrosion resistance than metal-based BPs and better mechanical properties than graphite BPs, are a promising alternative. In this study, we tried to develop graphite-epoxy composites meeting the technical US DOE targets for 2020, with a proper choice of manufacturing conditions that ensure a good compromise between conductivity, flexural strength, and gas permeability. In particular, we studied the influence of the filler to binder ratio, changed the molding temperature and time, and investigated the effects of increasing pressure both on in-plane conductivity and on helium permeability. We found that both formulation and molding pressure are crucial in determining the permeability of the graphite-epoxy composites, whereas molding temperature and time seem to play a minor role.

Lithium oligo-α-pyridylamides are useful intermediates in coordination chemistry. Upon trans-metalation they have afforded a variety of extended metal atom chains (EMACs), which are currently investigated as molecular wires and single-molecule magnets. However, structural information on this class of compounds is scarce. Two trilithium salts of a new, sterically encumbered oligo-α-pyridylamido ligand were isolated in crystalline form and structurally characterized in the solid state and in solution. Lithiation of N2-(trimethylsilyl)-N6-{6-[(trimethylsilyl)amino]pyridin-2-yl}pyridine-2,6-diamine (H3L) with n-BuLi in thf yielded dimeric adduct [Li6L2(thf)6] (1), which was crystallized from n-hexane/thf as 1·C6H14. Crystals of a tetra-thf solvate with formula [Li6L2(thf)4] (2) were also obtained. The compounds feature two twisted L3− ligands exhibiting a cis-cis conformation and whose five nitrogen donors are all engaged in metal coordination. The six Li+ ions per molecule display coordination numbers ranging from 3 to 5. Compound 1·C6H14 was investigated by multinuclear 1D and 2D NMR spectroscopy, including 1H DOSY experiments, which indicated retention of the dimeric structure in benzene-d6 solution. To the best of our knowledge, 1 and 2 are the longest-chain lithium oligo-α-pyridylamides structurally authenticated so far, thereby qualifying as appealing intermediates to access high-nuclearity EMACs by trans-metalation.

Chemical garden (CG) from copper(II) sulfate, nitrate and chloride (CG CuSO4, CG Cu(NO3)(2), CG CuCl2) were grown, and characterized from the structural and compositional point of view by using scanning electron microscopy, X-ray powder diffraction, elemental analysis, thermogravimetric analysis coupled with mass spectrometry, and DR (diffuse reflectance) UV-Vis-NIR spectroscopy. The main crystalline phases, controlled by the anion of the starting salt, were brochantite and kobyashevite for CG CuSO4, gerhardtite, rouaite and anthonyite for CG Cu(NO3)(2), and atacamite for CG CuCl2. The materials were then exposed to ammonia vapors to test the effectiveness of their entrapping property. All materials proved to be very efficient and rapid in the uptake of ammonia, which invariably results in the formation of a Cu(II)/NH3 complex. However, after a few tens of minutes, CG Cu(NO3)(2) and CG CuCl2 release water and get wet, thereby resulting unsuitable for applications. Only CG CuSO4 remains dry for at least 25 hours. This makes it a valid candidate for building devices for trapping ammonia, and possibly other gases capable of interacting with Cu(II). The entrapment of ammonia by this material was also characterized by H-1 and Si-29 MAS-NMR XAS spectroscopies.

Tetragallium(III) complex in [Ga-4(L4-Py)(2)(dpm)(6)] . EtOH, with H3L4-Py=2-(hydroxymethyl)-2-(pyridin-4-yl)propane-1,3-diol and Hdpm=dipivaloylmethane, was investigated as a diamagnetic analogue of tetrametallic, propeller-like single-molecule magnets (SMMs). The chiral molecular structure partitions the six CH2 protons of each tripodal (L4-Py)(3-) ligand into two diastereotopic sets. The two signals were clearly detected by H-1 NMR spectroscopy in C6D6, proving that ? and Delta enantiomers interconvert slowly over NMR timescale. Density functional theory calculations provided quantitative agreement with the observed values of chemical shifts and scalar coupling constants across both geminal and long-range interaction pathways. The solid-state structure suggests the occurrence of a lower symmetry stereoisomer (27 mol%), which was clearly identified in the NMR spectra. Since high spin Fe3+ forms distinctly more inert complexes than Ga3+, comparable or greater configurational stability is expected for the isostructural Fe-4(III), (Fe3CrIII)-Cr-III, and (Fe3VIII)-V-III SMMs, which are difficult to investigate by solution NMR because of the strong paramagnetism.