Operando X-ray absorption spectroscopy (XAS) is a powerful method to probe structural and electronic changes in electrocatalysts under reaction conditions, providing essential insight for the rational design of sustainable catalytic systems. However, the lack of suitable electrochemical cells for strongly absorbing biomass-derived electrolytes, such as lignin-containing media, remains a significant challenge. To date, there have been no reports of a transmission-capable setup for this type of electrolyte systems. We hereby present a newly developed modular operando XAS cell that is chemically resistant, mechanically robust, and reproducibly assembled, specifically designed to support studies in biomass electrocatalysis. The design incorporates 3D-printed polypropylene components, Kapton (R) windows, FKM seals, and steel reinforcements, thereby ensuring stable operation under alkaline conditions. It is noteworthy that the configuration facilitates both fluorescence and transmission measurements. In the present study, transmission mode was deliberately employed to circumvent self-absorption artifacts and to optimize data quality. The cell was benchmarked with copper nanoparticles on carbonized cellulose during the electrocatalytic depolymerization of Kraft lignin, a key step in biomass valorization. Operando XAS revealed the structural stability of the metallic Cu0 state up to -0.74 V versus RHE, while increased noise at more negative potentials correlated with gas bubble formation from water splitting. In accordance with the FAIR principles (Findable, Accessible, Interoperable, and Reusable), all technical drawings and design details are made openly available to promote transparency, reproducibility, and reuse by the broader scientific community. By disclosing both the strengths and limitations of the present study, this work provides a practical blueprint for future studies. We present an operando electrochemical XAS cell enabling transmission measurements for lignin depolymerization, thereby establishing a methodological benchmark for greener and more efficient electrochemical processes for biomass conversion.
The platinides Nd5Sn9Pt7 and Gd5Sn9Pt7 were synthesized by arc-melting of the elements and subsequent annealing. Nd5Sn9Pt7 (a = 437.43(6) pm, b = 2872.2(4) pm, c = 727.8(1) pm) and Gd5Sn9Pt7 (a = 428.37(8) pm, b = 2869.7(5) pm, c = 720.4(1) pm) crystallize with the non-centrosymmetric Zr5Pd9P7-type structure, orthorhombic space group Amm2. The structure of the gadolinium compound was refined from single-crystal X-ray diffractometer data. Refinements of the occupancy parameters revealed the formation of tiny defects on four Wyckoff sites, leading to composition Gd4.95(1)Sn8.94(1)Pt6.89(2) for the studied crystal. The tin and platinum atoms build up a three-dimensional [Sn9Pt7]delta- polyanionic network with pronounced Sn-Pt bonding (264-289 pm). The Sn3 atoms show formation of a Sn3-Sn3 dumb-bell with a distance of 320 pm. The three crystallographically independent gadolinium atoms are located within distorted pentagonal prismatic channels. They are coordinated by the platinum and tin atoms: Gd1@Pt6Sn8, Gd2@Pt5Sn8 and Gd3@Pt5Sn8. Temperature-dependent magnetic susceptibility studies show Curie-Weiss paramagnetism for Gd5Sn9Pt7 and an experimental magnetic moment of 8.12(1) & micro;B per Gd atom, compatible with stable trivalent gadolinium. Gd5Sn9Pt7 is ordered antiferromagnetically below a N & eacute;el temperature of TN = 15.6(1) K.
Rare earth elements (REE) and their compounds are widely used for the production of components of consumer technology. Current geopolitical considerations have brought them to the forefront of international discussion and highlight the need for development of strategies for more efficient mining, processing, use, and recycling. However, advanced technology relies on robust thermodynamic data to understand the formation of REE-bearing compounds and limitations of their use, and such data are not well constrained and sometimes contradictory. In this study we use solution calorimetry to accurately determine the energetics of two of the most important groups of rare earth materials: the rare earth metals and their common oxides. Rare earth metals were dissolved in aqueous 5 N HCl at 298 K and yielded solution enthalpies ranging from -645 kJ mol-1 to -725 kJ mol-1. The common oxides, including most sesquioxides (REE2O3) and other stable oxide phases where appropriate, were dissolved in the melt of 3 Na2O & centerdot;4 MoO3 at 1,073 K and yielded drop solution enthalpies ranging from -220 kJ mol-1 to -50 kJ mol-1, with the exception of CeO2, which had a positive drop solution enthalpy of about 90 kJ mol-1. The formation enthalpies of REE oxides from the literature were combined with our data to calculate the respective drop solution enthalpies of the metals in sodium molybdate melt and the dissolution enthalpies of the oxides in aqueous 5 N HCl. These data are currently the most reliable reference state data for the majority of rare earth metals and oxides, including results for previously unstudied materials, and can be considered state of the art for studies and software requiring thermodynamic data going forward.
The complexes [Co(ima)(2)(nba)(2)(H2O)(2)] (1) and [Co(Hima)(2)(bta)(H2O)(2)] (2) have been synthesized and characterized by single-crystal X-ray diffraction and IR spectroscopy (ima = 4-(1H-imidazol-1-yl)aniline, Hnba = 4-nitrobenzoic acid, H(4)bta = benzene-1,2,4,5-tetracarboxylic acid). Complex 1 has a mononuclear structure while complex 2 exhibits a multinuclear chain structure. These components are further extended to afford kgd sheets for 1 and a three-dimensional fsc network for 2, with the aid of abundant hydrogen-bonding interactions. The structural diversity indicates that the carboxylate ligands induce a change in the protonation state of the ima ligand in the two complexes, thereby playing a critical role in the increase of the dimensionality of the supramolecular substructures from 2D in 1 to 3D in 2.
This study aims to evaluate the physicochemical properties of local coal fly ash (CFA) as a secondary cementitious material (SCM) with a focus on improving the strength activity index (SAI) on final mortar strength. Ordinary Portland cement (OPC) was partially replaced with CFA, i.e. 5-30 % by weight and mixed with sand and water to form mortar and tested for setting time, consistency, workability, heat of hydration and compressive strength, focusing on the strength activity index for 3, 7 and 28 days under standard conditions. The investigations revealed that both initial and final setting times and workability of CFA-blended OPC increase, which is beneficial for desirable construction applications. However, the consistency decreases slightly, which could be due to the decrease in demand of water for hydrated mortar. The initial and final hydration temperature of CFA-blended OPC decreases, whereas the time to reach maximum hydration temperature increases. The results showed that after 28 days of curing, OPC blends with CFA improve the compressive strength of the mortar. This highlights the effective reutilization of local CFA as a low-cost and viable SCM with enhanced compressive strength. The formulation allows to develop construction materials with improved properties and also to mitigate environmental problems due to coal burning.
The intermetallic phases RE3Co9In2 (RE = Pr, Nd, Sm) were obtained by arc-melting of the elements in an argon atmosphere followed by annealing at T = 600 degrees C for 1,500 h in evacuated and sealed quartz ampoules. All samples were characterized through their powder X-ray diffraction patterns and metallographic and quantitative phase analyses. The crystal structure of Pr3Co9In2 was refined from powder X-ray diffraction data using the Fullprof program package. The compound crystallizes in a Sm2Co9In3-related structure type (orthorhombic space group Cmmm, Z = 2; a = 23.123(4); b = 5.1003(7); c = 4.0423(5) & Aring;) and is a two-layer structure with layers perpendicular to the z direction. The crystal structure of Pr3Co9In2 is based on the intergrowth of CaCu5- and CsCl-type related slabs and is a member of the homologous series RE2m+2n+2pT2m+2nX2n+2p, where m and n are the numbers of RET5 and RET4X (CaCu5 type) slabs and p is the number of REX (CsCl type) slabs (T = Co, X = In), respectively. For Pr3Co9In2 the values are m = n = p = 2. Isostructural compounds were obtained with Nd and Sm.
A series of differently substituted chalcones, Ar-C(O)CH=CH-Ar ' (1-17), were synthesized and characterized using FT-IR, 1H NMR, 13C NMR, and mass spectrometry. All the compounds were screened for antifungal activity against the pathogenic yeast Candida albicans by agar diffusion assay at concentrations of 0.5, 1, and 2 mg mL-1. Eight compounds (2, 3, 7, 8, 11, 12, 16, and 17) demonstrated significant inhibitory activities, producing inhibition zones of 12-18 mm at 1-2 mg mL-1. No inhibition was observed at 0.5 mg mL-1 for any compound except 8, which showed the highest overall activity, yielding inhibition zones of 11, 15, and 18 mm at 0.5, 1, and 2 mg mL-1, respectively. To investigate their mechanism of action, molecular docking studies were performed, which verified the ability of these compounds to bind to the C. albicans N-myristoyltransferase active site (PDB ID: 1IYL) through hydrogen-bond interactions involving key residues such as Gln-226, Cys-393, and Asn-392. Docking simulations analysis identified compound 3 as the most promising inhibitor, showing stable binding interactions (-11.71 kcal mol-1) with 1IYL, which suggests its potential as an antifungal therapeutic target. In addition, in-silico absorption, distribution, metabolism, and excretion (ADME) profiling predicted generally acceptable drug-like properties for these derivatives, including favorable topological polar surface area (TPSA) values and oral bioavailability, with low predicted toxicity for most derivatives. Overall, the combined in-vitro and in-silico results identify compounds 3, 7, 8, and 16 as the most promising candidates for further antifungal optimization and mechanistic evaluation.
Under hydrothermal conditions, Co(II) nitrate reacts with 4,4 '-bis(2-methyl-1H-imidazol-1-yl)biphenyl (L1) and benzene-1,2,4,5-tetracarboxylic acid (H4L2) to yield the new complex [Co(HL1)(L2)0.5(H2L2)0.5]& centerdot;H2O (1); when Cu(II) nitrate is reacted with the L1 and 3-nitrophthalic acid (H2L3), the product with the formula [Cu2(L1)2(L3)2(H2O)4]& centerdot;6H2O (2) is obtained. Complexes 1 and 2 have been characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental and thermogravimetric analyses. In the solid state, complex 1 shows a net structure with binodal (3,4)-connected (4.62)2(42.62.82) topology; while complex 2 displays a 1D zigzag structure. Tetra-nuclear and hexa-nuclear water clusters exist in the structure of this compound 2. The fluorescence properties of compound 1 were also investigated.
In this communication the existence of a diamond-like novel triclinic allotrope tri-C-8 with space group P1 , No. 2, is proposed from crystal engineering of corner-sharing stacking of C-4 tetrahedra. DFT-based calculations of the ground-state structure show that tri-C-8 belongs to "sie; deh3" topology characterizing the base-centered orthorhombic C-16 allotrope and considered thereupon as a distorted higher-symmetry structure. Energy-derived properties such as the cohesive energy, the mechanical, dynamic, thermodynamic characteristics, and the electron band structure show close relationship with diamond. Specifically, the high density rho = 3.43 g cm(-3), versus rho(diamond) = 3.53 g cm(-3), the ultra-hard behavior with Vickers hardness H-V = 83 GPa versus, H-V(diamond) = 95 GPa, the specific heat C-V curve fitting well with diamond's experimental values and the largely insulating electronic system.
The rare earth-rich intermetallic cadmium compounds RE14Ni3Cd3 (RE = Dy-Tm, Lu) were synthesized by induction melting of the elements in sealed tantalum ampoules, followed by annealing in sealed quartz tubes in muffle furnaces. The polycrystalline samples were characterized by powder X-ray diffraction, confirming isotypism with Gd14Co3In2.7, space group P42/nmc. The structures of the holmium and lutetium compound were refined from single-crystal X-ray diffractometer data: a = 945.03(3), c = 2,275.64(7) pm, wR2 = 0.0316, 2800 F2 values, 64 variables for Ho14Ni3.70(1)Cd2.27(1) and a = 929.79(3), c = 2,237.53(6) pm, wR2 = 0.0537, 1315 F2 values, 63 variables for Lu14Ni3.69(3)Cd2.31. The striking structural feature of these cadmium phases is the formation of small defects on one 8g nickel site and Cd/Ni mixing on the Wyckoff position 4c. The complete RE14Ni3Cd3 structures can be described by a condensation of tricapped trigonal prisms around the nickel and icosahedra around the cadmium atoms. Temperature dependent magnetic susceptibility studies have revealed Curie-Weiss paramagnetism for Ho14Ni3Cd3, Er14Ni3Cd3 and Tm14Ni3Cd3 with antiferromagnetic transitions in the low-temperature regime (TN = 13.1(1), 8.6(1) and 3.6(1) K for RE = Ho, Er and Tm, respectively).
Mixtures of aqueous solutions of 2-methylimidazole and oxalic acid, in molar ratios of 1:2 and 2:1, were investigated, leading to the isolation of two 2-methyl-1H-imidazol-3-ium (2-methylimidazolium) oxalate salts. Compound [C4H7N2][0.5C2O4][H2C2O4][H2O] (1) was isolated as a co-product in the presence of trimethyltin chloride, whereas [(C4H7N2)2][C2O4] (2) was obtained directly from the aqueous reaction. Both compounds were characterized by FT-IR spectroscopy, Hirshfeld surface analysis, elemental analysis and single-crystal X-ray diffraction. Salt 1 crystallizes in the monoclinic system, space group C2/c, with unit cell parameters a = 24.682(4), b = 3.7589(7), c = 22.829(4) & Aring;, beta = 113.486(4)degrees, V = 1,942.5(6) & Aring;3 and Z = 8. The four components of 1, 2-methylimidazolium cations, oxalate anions, oxalic acid and water are connected through intermolecular hydrogen bonds. Salt 2 crystallizes in the orthorhombic system, space group Pbca, with a = 13.9808(9), b = 13.3039(10), c = 19.6563(13) & Aring;, V = 3,656.1(4) & Aring;3 and Z = 12. Two 2-methylimidazolium cations compensate for the two negative charges of an oxalate anion. The packing of the building units in the two salts features the propagation of a three-dimensional network in 1, whereas in 2 it is restricted to a layered arrangement.
The presence of carbon dioxide in natural gas leads to reductions in the CH4 calorific value and to corrosion of transportation pipelines, making it necessary for the CO2 concentration to be reduced below 2 %. In this study, a porous organic polymer (POP) named BDA-TG((Cl)(-)) was synthesized via an aqueous method using the dialdehyde 4,4 '-biphenyldicarboxaldehyde and triaminoguanidine hydrochloride as reagents. The BDA-TG((Cl)(-)) COF-C material was synthesized by carbonization of BDA-TG((Cl)(-)) at T = 900 degrees C for 4 h under an atmosphere of CO2. Experimental results demonstrated that the as-prepared carbon material exhibits outstanding CO2 adsorption and separation performance, with a specific surface area of 783 m(2) g(-1) and a CO2 adsorption capacity of 3.57 mmol g(-1) at T = 273 K. The CO2/CH4 adsorption selectivity was calculated based on the IAST model, ranging from 7.03 to 8.88. In the gas breakthrough experiment, the breakthrough time of CO2 was prolonged by 25 min relative to CH4, demonstrating excellent CO2 adsorption and separation performance.
The rare earth metal(III) oxotellurates(IV) RE 2Te3O9 (RE = Y, Sm-Tb, Ho and Er) could be synthesized through solid-state reactions at temperatures near 850 degrees C from mixtures of the oxides RE 2O3 and TeO2 in a 1 : 3 M ratio with cesium bromide (CsBr) as fluxing agent. They crystallize in the monoclinic space group P21/c, thus being isostructural to the already known B-type Dy2Te3O9 with unit cells and molar volumes decreasing monotonously from Sm2Te3O9 (a = 1389.81(9) pm, b = 545.14(3) pm, c = 2304.97(14) pm, beta = 98.942(3)degrees) to Er2Te3O9 (a = 1365.71(9) pm, b = 535.48(3) pm, c = 2261.04(14) pm, beta = 99.053(3)degrees) according to the lanthanoid contraction. The crystal structure contains four crystallographically independent RE 3+ cations, which are hepta- or octacoordinated by oxygen atoms. Three types of rare earth metal-oxygen polyhedra [(RE1-RE3)O8]13- form two types of zigzag chains by edge-sharing running along [010], which are further connected with each other via common edges to layers spreading out parallel to (100). The remaining [(RE4)O7]11- polyhedron is attached to a layer above and below via common edges generating corrugated R E 4 O 17 22 - infinity 2 sheets parallel to the (100) plane. For the oxotellurate(IV) partial structure, the six crystallographically different Te4+ cations in psi 1-tetrahedral [TeO3]2- units are linked through strong secondary Te4+O2- contacts to form screw-like Te 5 O 15 10 - infinity 1 strands propagating along the [010] direction with 21 screw axes running through their centres. The Raman spectra of all B-type RE 2Te3O9 members are reported and discussed, and the orientation of the lone pairs at the Te4+ cations is defined.
The compound Cr51Ni23B168O337(OH)29 has been obtained through an explorative high-pressure/high-temperature experiment at 9 GPa and 1,200 degrees C. This borate crystallizes in the trigonal space group R 3 & oline; m $R\overline{3}m$ with the unit cell parameters a = 10.4387(1), c = 51.5121(1) & Aring;, V = 4,861.1(2) & Aring;3, and one formula unit per cell. The crystal structure is a complex framework, composed of corner-sharing tetrahedral [BO4] groups and edge-sharing [(Cr,Ni)O6] octahedra. In this contribution, the structural data and the infrared spectrum of Cr51Ni23B168O337(OH)29 are presented.
Ba2[LiGaO4] was prepared via a solid-state reaction in a weld-shut tantalum ampoule at T = 1,073-1,123 K. The quaternary barium oxolithogallate crystallizes in the trigonal crystal system and the crystal structure was solved and refined in the non-centrosymmetric space group P3221 (no. 154) with the lattice parameters a = 5.8361(4) & Aring; and c = 13.320(2) & Aring;. The structure can be constructed from vertex-sharing LiO4 and GaO4 tetrahedra forming a three-dimensional tetrahedron [LiGaO4]4- substructure. The charge of this anionic network is compensated by the Ba2+ ions in eightfold coordination, forming irregularly shaped BaO8 polyhedra. Ba2[LiGaO4] was found to crystallize isotypically to the known barium oxolithoaluminate Ba2[LiAlO4], both of which are ordered variants of the BaZnO2-type structure. The structure elucidated from single-crystal X-ray diffraction is representative for the powder sample and the element ratio of Ba:Ga is supported by the results of an EDX analysis.
The intermetallic compounds AEAuPb (AE = Ca, Sr, Ba) were synthesized from the elements and structurally characterized as isopointal to the orthorhombic KHg2-type structure (Imma, CaAuPb: a = 4.8068(9), b = 7.3795(5), c = 8.327(1) A; SrAuPb: a = 4.9038(2), b = 7.7977(3), c = 8.4651(4) A; BaAuPb: a = 5.0266(4), b = 8.1804(4), c = 8.6834(8) A). Single-crystal X-ray diffraction of SrAuPb revealed mixed Au/Pb site occupancy, while isotypic CaAuPb and BaAuPb structures were obtained from powder X-ray diffraction. All three compounds exhibit metallic conductivity and weak, temperature-independent Pauli paramagnetism, consistent with nonmagnetic, delocalized electronic states. These results identify the AEAuPb series as nonmagnetic Au-Pb plumbides with mixed site occupancy and provide a basis for further exploration of spin-orbit coupling effects arising from the presence of gold and lead.
Explorative high-pressure/high-temperature syntheses (9 GPa, 1,200 degrees C) starting from NiO and H3BO3 yielded a product mixture containing single crystals of NiB6O8(OH)4, a new orthorhombic borate (space group Fdd2) with the lattice parameters a = 39.097(4) & Aring;, b = 4.3880(4) & Aring;, c = 7.5899(8) & Aring;, V = 1,302.1(2) & Aring;3, and eight formula units per cell. This compound is the third one in the structural class of borates with the general formula M(B6O9-x )(OH)3+x (M = In3+, Sc3+ (x = 0), Ni2+ (x = 1)). The reaction product has been studied by means of powder X-ray diffraction, and an infrared spectrum of a single crystal has been recorded. Results of BLBS and CHARDI calculations are presented.
The MgCuAl2-type intermetallic phases CaPtIn2 and EuPtIn2 form a complete set of solid solutions Eu1-xCa x PtIn2 with a Vegard-type, almost linear decrease of the cell volume with increasing calcium content. The structure of Eu0.579(16)Ca0.421PtIn2 was refined from single-crystal X-ray diffractometer data: Amm2, a = 783.09(2), b = 442.91(6), c = 1,055.54(4) pm, wR = 0.0356, 1054 F2 values and 33 variables. This subgroup refinement yielded a europium accumulation on site 2a and a calcium accumulation on site 2b, pointing to an ordered arrangement. Temperature dependent magnetic susceptibility studies showed Curie-Weiss paramagnetism for all Eu1-xCa x PtIn2 samples. Ferromagnetic ordering is detected at low temperature with a decrease of the Curie temperature from 32.8(1) K for EuPtIn2 to 2.0(1) K for Eu0.1Ca0.9PtIn2. The decrease in TC proceeds in a sigmoidal manner with the inflection point close to the ordered composition Eu0.5Ca0.5PtIn2. The stable divalent europium ground states are corroborated by 151Eu M & ouml;ssbauer spectroscopy.
The new fluoride oxoselenate(IV) CeF[SeO3] was synthesized from cerium dioxide (CeO2), cerium metal (Ce), cerium trifluoride (CeF3) and selenium dioxide (SeO2) at 700 degrees C in appropriate stoichiometric ratios with a surplus of fluxing cesium bromide (CsBr) by utilizing corundum-embedded silica tubes. It crystallizes in the monoclinic space group P21/c with the lattice parameters a = 1805.14(9) pm, b = 707.83(4) pm, c = 838.26(5) pm and beta = 97.049(3)degrees for Z = 12. Its crystal structure comprises three crystallographically independent Ce3+ cations, which are surrounded by both oxide and fluoride anions in different ratios within polyhedra described as [(Ce1)O6F4]13-, [(Ce2)O4F7]12- and [(Ce3)O10]17-. The fluoride-bearing ones share common edges and faces to erect corrugated { infinity 2 ${}_{\infty }{}<^>{2}\left\{\right.$ [Ce2O5F3]7-} sheets and so do the fluoride-free ones according to { infinity 2 ${}_{\infty }{}<^>{2}\left\{\right.$ [(Ce3)O5]7-}. The alternating interconnection via common oxygen vertices leads to a three-dimensional { infinity 3 ${}_{\infty }{}<^>{3}\left\{\right.$ [Ce3O9F3]15-} framework, whose structural stability is further enhanced by charge-compensating Se4+ cations through connectivity via three distinct types of oxoselenate(IV) groups [SeO3]2-, easily identified by Raman spectroscopy depicting the four expected modes of these discrete psi 1-tetrahedral [SeO3]2- anions. Another structure description for CeF[SeO3] highlights cationic { infinity 2 ${}_{\infty }{}<^>{2}\left\{\right.$ [Ce2F3]3+} compartments with (Ce1)3+ and (Ce2)3+ as well as anionic { infinity 2 ${}_{\infty }{}<^>{2}\left\{\right.$ (Ce[SeO3]3)3-} compartments with (Ce3)3+ in alternating stacking along [100], which resemble very much the pure CeF3- and Ce2[SeO3]3-structure sections to explain the large number of formula units (Z = 12) for this rather simple composition (CeF[SeO3]).
A helical polymer (poly-2 200) is synthesized which contains a pyrrolidine structure using (S)-(aminomethyl)-1-boc-pyrrolidine as the starting material. The catalyst demonstrates significant solvent-dependent stereoselectivity in asymmetric aldol reactions, with chloroform emerging as the optimal medium achieving enantiomeric excess (ee) of 68.4 % and a diastereomeric ratio (dr) of 73:27 for the cyclohexanone-4-nitrobenzaldehyde coupling. The catalyst exhibits broad substrate compatibility, processing electron-deficient aromatic aldehydes (4-CN, 4-NO2, 2-CF3) with distinct stereochemical outcomes. Particularly noteworthy is the catalyst's ability to maintain moderate enantiocontrol (46.8 % ee) even with sterically demanding 2-(trifluoromethyl)benzaldehyde. This indicates that the catalyst has relatively good catalytic activity and shows excellent application prospects in asymmetric catalysis.
