Modification of composition via solid solution can significantly improve the physical properties of materials. The crystallographic properties of the novel Mg3V2(1-x)Nb2xO8 solid solution were investigated by X-ray powder diffraction (XRPD) and spectroscopy. XRPD analysis confirms crystallization in the Cmca space group, corresponding to the kagome-staircase Ni3(VO4)2-type structure. Rietveld refinements reveal that Nb substitution induces a systematic increase in lattice parameters and unit cell volume. However, the lattice parameters remain constant for x > 0.04, indicating a solid solution limit of approximately x ∼ 0.04. Spectroscopic analysis further indicates tetrahedral coordination of Nb dopants, as evidenced by the characteristic energy positions and splitting of the Nb L3 edge spectra. High-temperature XRD studies (298-1273 K) revealed pronounced anisotropic thermal expansion. The volumetric thermal expansion coefficient increases from 19(2) MK-1 at 298 K to 40.6(5) MK-1 at 1273 K. Electronic structure calculations based on density functional theory yield a band gap of 3.57 eV, which is in good agreement with previously reported experimental data. The calculated Debye temperature (734 K) indicates high lattice rigidity. The observed trend in directional compressibility (a > c > b) correlates well with the experimentally measured anisotropic thermal expansion, confirming the a-axis as the most responsive under both thermal and mechanical conditions.

This study focuses on the binary δ-Co2.5Zn17.5 and pseudobinary δ-Co2.5-xMnxZn17.5 (x = 0-1.2) intermetallic phases, prepared via a high-temperature synthetic route. The crystal structure and atomic distribution of δ-Co2Mn0.5Zn17.5 were established using X-ray and neutron diffraction experiments. The pseudobinary δ-Co2Mn0.5Zn17.5 adopts a chiral crystal structure (P64), consistent with the binary δ-Co2.5Zn17.5. Theoretical calculations were employed to understand the site preferences of Co and Zn, as well as the overall phase stability of the binary compound. Interestingly, the substitution of Mn for Co occurs through Zn mediation (an indirect substitution). In the crystal structure, Mn occupies Zn sites at the 6c position; the displaced Zn then occupies the 3a site, ultimately maintaining the stoichiometry of Co2Mn0.5Zn17.5. The binary δ-Co2.5Zn17.5 exhibits diamagnetism, whereas Mn incorporation into the binary δ-Co2.5Zn17.5 induces cluster-glass magnetism in the pseudobinary δ-Co2Mn0.5Zn17.5, with a spin-freezing temperature of 10 K. While both compounds are structurally chiral, this chirality does not appear to influence their magnetic behavior. Instead, the cluster-glass state in the Mn-substituted phase is driven by the atomic randomness of the Mn atoms in the structural lattice. This out-of-equilibrium behavior below 10 K is further supported by the alternating-current (ac) magnetic susceptibility, thermoremanent magnetization, and the thermal memory effect.

The development of advanced physisorption-based adsorbents is essential for carbon dioxide (CO2) capture technologies. While metal-organic frameworks (MOFs) offer a promising alternative to traditional carbon capture methods, they often face a trade-off between high adsorption affinity and energy-intensive regeneration. In this work, we report an anionic copper-triazolate framework, NCKU-56 (NCKU = National Cheng Kung University), incorporating quinone-based organic linkers. The 1D channels exhibit moderate structural flexibility and reversible lattice adjustments that are specifically correlated with CO2 adsorption. This material demonstrates high CO2/N2 IAST selectivity of 65 and 315 (50/50, 15/85, v/v) at 298 K and a moderate isosteric heat of adsorption of 30.1 kJ mol-1, which facilitates rapid regeneration without high thermal energy penalties. Crystallographic analysis reveals that the selective uptake is driven by cooperative host-guest interactions, including quadrupole-π interactions (with quinone cores and triazolate rings) and hydrogen bonding between CO2 and [NH2(CH3)2]+ cations. Breakthrough experiments confirm the practical efficacy of NCKU-56 for CO2/N2 separation, highlighting the potential of integrating polar functional groups and π systems with moderate framework flexibility for energy-efficient carbon capture.

Polyoxovanadate clusters offer atomically defined platforms for studying how electronic structure influences reactivity at molecular metal-oxide surfaces. In this computational study, we investigated the coupling between reduction state and alkylation reactivity in the hexavanadate cluster [V6O13(TRIOLX)2]2- (TRIOL = tris(hydroxymethyl)methane; X = -CH3, -NO2) through a systematic analysis of successive methylation and reduction pathways using density functional theory and microkinetic modeling. The calculations show that changes in electron count redistribute the nucleophilicity of bridging μ2-oxo ligands, leading to redox-dependent regioselectivity during sequential methylation. Microkinetic simulations further indicate that several thermodynamically accessible intermediates do not accumulate because they are rapidly consumed in subsequent transformations, consistent with the need for stepwise synthetic strategies to isolate certain dimethylated species. In addition, substituent effects on the TRIOL ligands follow Hammett-type correlations, allowing rapid estimation of electronic trends without additional quantum chemical calculations. Overall, the results provide a detailed picture of how reduction state influences accessibility and selectivity during polyoxovanadate methylation.

We report the synthesis, structure, and magnetic properties of two 1:3 ordered quadruple perovskites Sr4MRu3O12 (M = Li and Na). Sr4NaRu3O12 crystallizes in the centrosymmetric space group R3̅, and Sr4LiRu3O12 appears to be isostructural to the Na compound based on the PXRD data. In Sr4NaRu3O12, both Na and Ru are predominantly ordered at the B sites (here Na/Li and Ru), and the structure contains only corner-connected RuO6 and NaO6 octahedra. This atomic ordering also leads to a rather large unit cell with a = 11.25 Å and c = 27.6 Å compared to the basic 12R structure (a ∼ 5.5 Å and c ∼ 27 Å). Magnetic measurements reveal that Sr4NaRu3O12 undergoes a magnetic transition to an antiferromagnetic state below TN ∼ 265 K, confirmed by DSC and neutron diffraction. The Ru moments show a collinear antiferromagnetic spin alignment along the hexagonal c-axis with a propagation vector k = (0, 0, 1.5). Interestingly, those Ru moments lying on the 3-fold roto-inversion do not significantly contribute to the magnetic order, since they are located between antiferromagnetically coupled Ru atoms and are therefore highly frustrated. Sr4LiRu3O12 shows a magnetic anomaly around 110 K, possibly associated with competing ferromagnetic and antiferromagnetic interactions.

Accessing the tetrafluoroargentate anion [AgF4]-, a powerful oxidizing agent, with the silver atom in the formal oxidation state +III, so far required the handling of elemental fluorine and anhydrous HF. Herein, we report a simple and safe method for generating tetrafluoroargentate salts on a preparative scale. Adding tetraalkylammonium halide salts, [NR4]X, or fluortetraphenylphosphorane, FPPh4 to silver difluoride in acetonitrile leads to the formation of the corresponding tetrafluoroargentate salt, [NR4][AgF4], or [PPh4][AgF4] and silver halide AgX via disproportionation. The reaction was monitored employing 19F and 109Ag NMR spectroscopy. In the single-crystal X-ray structure analysis, the expected square planar arrangement of the silver atom is observed, confirming the d8 configuration of the silver ion in the formal oxidation state +III. The fluorinating properties were demonstrated through the oxidation of bis(4-nitrophenyl)disulfide (aryl-S-S-aryl, with aryl = 4-NO2C6H4). The tetrafluoroargentate salt enables the oxidation of sulfur(I) to sulfur(VI), resulting in the formation of aryl-SF5. In strong contrast, treating the disulfide with AgF2 only results in the oxidation to the sulfur(IV) derivative, aryl-SF3, under the same conditions.

As the class of the smallest metallacycles, transition-metal metallacyclopropanes have been widely studied, whereas scandium, yttrium, and lanthanide analogues have remained elusive. Herein, we report the first synthesis and characterization of scandium and lutetium metallacyclopropanes, 2-Sc and 2-Lu. Reactivity studies reveal a striking divergence: while 2-Sc is limited to redox processes, 2-Lu displays versatile insertion reactivity with various unsaturated substrates. DFT analysis indicates that the superior reactivity of 2-Lu is not driven by electronic nucleophilicity but rather by kinetic accessibility. The larger ionic radius and rare coordination mode of the Lu center provide a more open coordination sphere that outweighs electronic stabilization. This work highlights the important role of steric accessibility in controlling the divergent reactivity of highly strained Sc- and Lu-metallacyclopropane complexes.

Artificial photocatalytic CO2 conversion to energy fuels is highly sought due to the carbon-neutral plan. However, resolving the sluggish photogenerated charge separation and migration in photocatalysts remains a challenge. Herein, we present an adsorption electro-neutralization confinement strategy in ionic liquid (IL)-tailored thorium-based metal-organic frameworks (Th-MOFs) for boosting interfacial charge migration while integrating the merits of enhanced CO2 adsorption and activation by dual sites (Th-MOF and ILs). The introduction of ILs via adsorption electro-neutralization has prolonged the excited charge lifetime from 26.45 ps to an exceptionally high value of 293.70 ps and reduced the exciton binding energy from 88.11 to 72.06 meV. The surface potential distribution of the photocatalysts, obtained using in situ Kelvin probe force microscopy (KPFM), corroborates the enhanced surface charge migration. Consequently, 1-(4-bromobutyl)-3-methyl-imidazolium bromide ([BMIMBr]Br)-derived Th-MOF-[BMIMBr]Br delivers CO with a yield of 408.43 μmol g-1 h-1, being 1.5 times higher than the pristine Th-MOF (274.11 μmol g-1 h-1). Computational investigations revealed that the IL-Th-MOF can significantly lower the Gibbs free energy of the *COOH intermediate, which may account for the superior photocatalytic performance. This work expands the Th-based MOF chemistry and its applications in photocatalysis, providing a new strategy for enhancing surface charge transfer.

A combined 3DED, plane-wave DFT, and Rietveld refinement workflow uncovers the first example of interlayer-twisting polymorphism in a pillared MOF. While the parent material, PUM198, a Zn-based mixed-ligand MOF, was previously synthesized under solvothermal conditions, mechanochemistry selectively affords a new polymorph, PUM198-m. Although the two phases share identical composition and connectivity, they differ in symmetry, layer arrangement, pore architecture, and topology. Accessible only as a microcrystalline powder, PUM198-m is unsuitable for conventional single-crystal X-ray diffraction, and its flexibility and solvent-filled pores preclude structure solution from the XRPD data. The crystal structure was therefore derived from a multitechnique blueprint in which the starting model was derived from 3DED data and subsequently refined through iterative DFT-assisted Rietveld analysis to describe the as-synthesized, guest-loaded material. This integrated workflow provides a broadly applicable structural elucidation strategy for flexible MOFs that are mechanochemically synthesized, for which conventional crystallographic analysis fails.

Six orange-red phosphorescent chiral Ag(I) complexes of general structure [Ag(N1^N2)(P^P)]PF6, where N1^N2 is a pyridyl- or quinolyl-functionalized benzo[d]thiazole and P^P is an enantiopure diphosphine of the BINAP family with axial chirality, are herein presented. The novel complexes have been extensively characterized from a chemical, structural, and photophysical point of view, resulting in a family of chiral Ag(I) coordination compounds with red photoluminescence. Their emissive properties can be attributed to ligand-centered triplet manifold excited states localized on the benzothiazole ligand (3LCbtz). Low photoluminescence quantum yield (PLQY) values are recorded in solution, as is typical of Ag(I) derivatives, whereas a remarkable switch-on of the emission is observed in the solid state, with samples of quinolyl-benzothiazole xylBINAP complexes R-3 and S-3 displaying PLQY as high as 50% and excited-state lifetimes in the millisecond range. Electron circular dichroism (ECD) spectra show strong activity in both solution and solid state as thin films for all the complexes. Time-dependent density functional theory (TD-DFT) calculations confirm the strong LCbtz nature of the major absorbing singlet and emissive triplet states and provide an argument behind the absence of circularly polarized luminescence (CPL) in these samples.

The oxidative esterification of biomass-derived furfural is a sustainable pathway to value-added chemicals, yet current catalytic systems typically require harsh oxidants and alkali additives, which limit scalability and complicate downstream processing. Herein, a single-atom manganese catalyst (MnSA@CN) with atomically dispersed Mn-N4 sites is fabricated by coordinating Mn2+ with 1,4-diazabicyclo[2.2.2]octane (N(CH2CH2)3N, DABCO), followed by controlled thermal treatment and acid leaching. Under mild, additive-free conditions (90 °C, ambient-pressure air), MnSA@CN affords quantitative conversion of furfural to methyl furoate with >99% selectivity in a single step. Radical scavenging experiments combined with density functional theory calculations reveal a cooperative activation mechanism: the Mn-N4 sites synergistically activate O2 and furfural, generating methanol-derived hydroxyl radicals that mediate direct C-H oxidation and esterification, thereby bypassing the conventional furoic acid intermediate. This work highlights the pivotal role of isolated Mn-N4 centers in substrate-oxidant coactivation and delivers a scalable, noble-metal-free catalytic platform for sustainable biomass valorization, bridging fundamental single-atom catalysis with practical biorefinery transformations.

While the enantiomeric separation of β-nitroalcohols from racemic mixtures is paramount to the manufacture of enantiopure pharmaceuticals, developing chiral separation materials that resolve these compounds with both high enantioselectivity and broad substrate scope remains a massive challenge. Herein, we report a homochiral porous coordination polymer, S-1, constructed from a C2-symmetric phenylalanine-derived ligand with a well-balanced combination of flexibility and rigidity. Assembled with tetrameric Cu4 clusters, S-1 features open channels of 8 Å × 14 Å, in which a confined amphiphilic chiral cavity decorated with peptide functional groups is periodically distributed. When utilized as a chiral adsorbent, this porous material is capable of resolving a series of pharmacologically important aromatic β-nitroalcohols with enantioselectivity up to 99.8%. Furthermore, the chiral adsorbent can be easily recovered and reused for five cycles without any apparent loss of enantioselectivity, demonstrating excellent recyclability. This work not only provides a reliable strategy for constructing amino acid-based porous coordination polymers but also offers a promising platform for targeted β-nitroalcohol resolution.

The control of spin-spin interactions is a central challenge in designing materials for quantum technologies. A promising avenue for increasing magnetic coupling between spin centers is to connect them via a delocalized π-conjugated system. Here, we synthesized a family of porphyrins (monomers, dimers, and trimers) with high-spin FeIII centers and studied their magnetic interactions. The linearly fused Fe(III)Cl porphyrin trimers exhibit nearest-neighbor and second-neighbor couplings of the same sign and order of magnitude (J12 = -24.3 GHz; J13 = -10.8 GHz) between spin centers at 0.84 and 1.7 nm separation, respectively. These antiferromagnetic interactions lead to frustration, realizing a nontrivial Heisenberg spin system. The persistence of the long-range exchange coupling (J13) demonstrates that π-mediation is effective despite the spin polarization of the π-system induced by the central iron center. This work establishes a design principle for constructing nontrivial antiferromagnetic Heisenberg spin chains in which metal spin centers interact over several nanometers.

Control of borane speciation through Me2PhN·BH3 formation enables HBcat-mediated, metal-free C-H borylation of (hetero)arenes via an electrophilic aromatic substitution pathway. The process operates without external catalysts or additives and provides a sustainable platform for accessing organoboron motifs, highlighting the untapped potential of simple hydroboranes in selective C-H functionalization.