A novel terphenyl bis-urea macrocycle, designed to combine structural confinement with photoactivity, was synthesized via dynamic covalent chemistry and tested in photodimerization and photodegradation experiments. Single-crystal X-ray diffraction of this...

In recent years, hybrid organic-inorganic metal halides have been at the forefront of materials research. Typically, the functional (e.g., optoelectronic) properties of hybrid halides are derived from the inorganic structural part, whereas the organic structural units can add extra advantages in terms of stability, rigidity, and processability. Here, we report the design, synthesis, and characterization of two new hybrid materials in which the outstanding photophysical properties originate from the organic structural part. The new compounds, (C15H16N)2CdCl4 and ((Br)C15H15N)2CdCl4, have 2D layered Ruddlesden-Popper-type perovskite structures. These hybrids are blue-white light emitters just like their corresponding pure organic salts, but with much improved emission efficiencies. Optical spectroscopy and density functional theory (DFT) studies confirm that photoemission comes from the trans-stilbene organic cations. The photoluminescence quantum yield (PLQY) values of these new materials are among the highest known, 50.83% and 26.60% for (C15H16N)2CdCl4 and ((Br)C15H15N)2CdCl4, respectively. This is up to a 5-fold increase as compared to the light emission efficiency of the precursor salt C15H16NCl (PLQY of 10.33%). Alongside their outstanding optical properties, their environmental and thermal stability allow their consideration for potential practical applications such as radiation detection. This work shows that hybrid metal halides can be compositionally and structurally engineered to have highly efficient photoemission originating from the organic components for fast scintillation applications.

High-quality single crystals of the formula K2[M(H2O)6][Zr2F12] (M = Fe, Co), Rb2[M(H2O)6][Zr2F12] (M = Fe, Co, Ni, Cu, Zn), Cs2[M(H2O)6][Zr2F12] (M = Fe, Co, Ni), and Cs2Zr3Mn3F20 were obtained through a mild hydrothermal synthesis. The new materials crystallize in the monoclinic space group P21/n. The crystal structures and chemical compositions were determined using single crystal and powder X-ray diffraction. The thermal and optical properties of these materials are reported. UV-vis diffuse reflectance data identifies d-d electronic transitions of the Co-, Ni-, and Cu-containing compounds. Each hydrated compound (except the Fe containing compounds) exhibits similar thermal decomposition, fully dehydrating by 200 °C based on thermogravimetric analysis measurements. Magnetic measurements indicate that the new compositions are paramagnetic down to 2 K.

Abstract Single crystals of lanthanide orthoborates containing Nd, Sm, Eu, Gd, and Tb, which crystallize in the vaterite structure, were synthesized via a subcritical hydrothermal method. NdBO3 has not previously been reported in the vaterite structure, and other compositions have only been reported as polycrystalline powders. These single-crystal structures are the first example of orthoborates crystallizing in the vaterite structure and can help in a more extensive characterization of these phases. The single-crystal structure data provide evidence for lanthanide orthoborates containing Nd, Sm, Eu, Gd, and Tb crystallizing in a disordered hexagonal vaterite polymorph. These data can help resolve existing ambiguities in the structural description of vaterite-type rare-earth orthoborates and offer a future structural framework for understanding their optical and magnetic behavior.

A series of potassium lanthanide germanates, KLnGe2O6 (Ln = Pr, Nd, Sm-Dy), were synthesized by flux crystal growth. Single-crystal structures were determined for all seven compositions. The series crystallize in the monoclinic space group C2/c. The lanthanide cations occupy, in a 2:1 ratio, octahedral and bicapped trigonal-prismatic coordination environments and connect via edge-sharing to form infinite chains. The chains are linked via Ge3O3O6/2 units to create a 3D structure. The magnetic properties of the Nd-containing member and the optical properties of the Eu- and Tb-containing members were investigated. The luminescence behavior of KEuGe2O6 is consistent with that of previous reports. Thermal stability was explored by using high-temperature powder X-ray diffraction.

Trivalent phosphines are classically defined by their nucleophilic character. The reversal of polarity, or umpolung, at phosphorus is a conceptually significant transformation leading to new reactivity. While geometrically constrained phosphines have been demonstrated to exhibit electrophilic character, similar behavior for trigonal phosphines is rare. In this study, we report direct experimental evidence of electrophilic behavior in a non-constrained trigonal phosphine enabled by the attachment of a redox-active boron cluster. The diphosphine 1-PtBu2-2-PiPr2-closo-C2B10H10 undergoes selective addition of anionic nucleophiles, including nBu- and CN-, at its PtBu2 group. These reactions are accompanied by a two-electron reduction of the carborane cage and its conversion from a neutral closo- to a dianionic nido- structure, demonstrating that cluster-centered redox activity drives phosphorus-centered electrophilicity. The resulting nido-carboranyl phosphines exhibit enhanced nucleophilicity at the remaining phosphine arm, enabling subsequent trapping with alkyl halides, carbon disulfide, and electron-deficient fluoroarenes. These findings establish redox-active boron clusters as platforms for inducing umpolung and provide a new strategy for accessing ambiphilic reactivity at phosphorus.

Inorganic-organic hybrid materials have been widely investigated for their applications in catalysis, optics, magnetism, and biomedicine. Copper halide complexes are of particular interest due to their structural diversity and physicochemical properties. Conventional crystal growth approaches, such as slow evaporation and hydro (solvo)thermal synthesis, typically require extended reaction times and often favor thermodynamically stable phases. In this study, we prepared ten copper-phenanthroline halide (X = Cl, Br, and I) complexes using both traditional hydrothermal reactions and microwave-assisted hydrothermal methods and obtained [CuI (C12H8N2)2][I3], [C12H9N2][CuI2]& sdot;(H2O)1.42, [CuI(C12H8N2)2]2[I]3[C12H9N2]& sdot;3(H2O), [Cu2Cl4(C12H8N2)2], [CuBr(C12H8N2)2]4[Cu2Br4][CuBr2][Br]2[C12H9N2]& sdot;(H2O)3.44, [CuBr2(C12H8N2)] and [Cu3Br3(C12H8N2)2]. The comparative results show that microwave-assisted reactions shorten the reaction time and yield additional products that are not accessible through conventional hydrothermal conditions. These findings demonstrate that microwave heating provides a complementary pathway to conventional approaches, broadening the range of accessible copper halide complexes and contributing to the design and exploration of inorganic-organic hybrid systems.

Three new rare earth borates, Na2.62Ln2.12(BO3)3 (Ln = Pr, Nd, Sm), were synthesized via a high-temperature solution reaction using a BaCO3-H3BO3-NaF flux and structurally characterized by single-crystal X-ray diffraction analysis. The compounds crystallize in the orthorhombic space group Amm2 with lattice parameters a = 5.0985(10) & Aring;, b = 11.180(2) & Aring;, c = 7.1483(14) & Aring;, and a unit cell volume of 407.48(14) & Aring;3 (Z = 2) for Na2.62Pr2.12(BO3)3, a = 5.0983(10) & Aring;, b = 11.181(2) & Aring;, c = 7.1491(14) & Aring;, and a unit cell volume of 407.51(14) & Aring;3 (Z = 2) for Na2.62Nd2.12(BO3)3, and a = 5.08630(10) & Aring;, b = 11.0993(2) & Aring;, c = 7.04200(10) & Aring;, and a unit cell volume of 397.552(12) & Aring;3 (Z = 2) for Na2.62Sm2.12(BO3)3. The new sodium rare earth borates crystallize in a three-dimensional framework consisting of zig-zag chains of lanthanide LnO9 polyhedra and mixed Na/LnO8 polyhedra linked to sodium NaO7 and NaO6 distorted polyhedra and trigonal planar BO3 groups. The new rare earth borates Na2.62Ln2.12(BO3)3 (Ln = Nd, Pr, Sm) are isostructural with the reported structures of Na3Ln2(BO3)3 (Ln = La, Nd, Sm), Na2.67Tb2.11B3O9 and Na3-3 delta Eu2+delta(BO3)3 (delta = 0.16), however, there are some structural differences that are discussed. The Fundamental Building Block (FBB) consists of two isolated BO3 trigonal planar units that can be written as 2: [(2 Delta)].

Pinckneya bracteata (Georgia bark) was historically used in the southeastern United States to treat intermittent fevers and has long been believed to contain quinine. In 1885, a bitter crystalline substance termed pinckneyin was isolated, but its structure remained unknown. Reproduction of the original extraction procedure combined with modern spectroscopic and single-crystal X-ray diffraction analysis definitively identifies pinckneyin as 7-hydroxycoumarin (umbelliferone). This work resolves a long-standing ambiguity in the phytochemical literature and clarifies the chemical basis for reassessing the historical medicinal use of P. bracteata.

Two-dimensional (2D) layered hybrid double metal halide perovskites have recently gained significant attention as lead-free and environmentally benign alternatives to lead halide perovskites. In this study, we report the photophysical properties of a 2D Dion-Jacobson (DJ) type hybrid double perovskite, (C3H12N2)2AgBiBr8, which exhibits both reversible thermochromism and promising X-ray radiation detection capabilities. This material shows transition from a low-temperature monoclinic P21/n phase to a high-temperature monoclinic C2/m phase at 121.83 °C along with a color change from yellow to bright orange. The phase transition is reversible and both single crystals and bulk powder samples of (C3H12N2)2AgBiBr8 remain stable for more than 30 heating-cooling cycles. Optical property characterization shows that (C3H12N2)2AgBiBr8 is a semiconductor with an indirect band gap of 2.42 eV. The material demonstrates a semiconductor resistivity of 2.8 × 1010 Ω cm, lower than those of other reported DJ-type hybrid double perovskites, and also shows response towards soft X-rays (8 keV) with a detector sensitivity of 188.52 μCGy-1 cm-2. These properties along with a very high signal-to-noise ratio (SNR) value (111.45) indicate the potential of (C3H12N2)2AgBiBr8 for direct radiation detection.

The mild hydrothermal method using sodium carbonate in the presence of HF(aq) resulted in a series of high-quality single crystals of Na3x Ln (2-x)F6 (Ln = Er-Lu). Sodium carbonate was found to strongly promote the formation and crystallization of the Na3x Ln (2-x)F6 phase under hydrothermal conditions. Structure determination was carried out by single-crystal X-ray diffraction. All four phases are isostructural and crystallize in the hexagonal space group P-6. Pure polycrystalline powders of Na3x Ln (2-x)F6 (Ln = Er-Lu) were obtained via flux synthesis using NaNO3/NaF as the flux.

A new layered uranyl sulfate fluoride compound, K(UO2)SO4F, was successfully synthesized as both single-crystals and polycrystalline powder under mild hydrothermal conditions. The compound K(UO2)SO4F crystallizes in the orthorhombic crystal system with the space group Pbca, exhibiting lattice parameters of a = 8.72140(10) & Aring;, b = 10.9204(2) & Aring;, and c = 13.2249(2) & Aring;, with unit cell volume V = 1259.56(3) & Aring;3 and Z = 8. The K(UO2)SO4F compound contains bicapped trigonal prismatic UO5F2 polyhedra that are connected to sulfate tetrahedra via vertex sharing to form two-dimensional 2 infinity[(UO)2SO4F]- sheets that are separated by K+ ions. The photoluminescence emission spectrum of K(UO2)SO4F is collected by using a confocal 375 nm diode laser and is presented. The TGA and IR data for this compound are discussed.

Stimuli-responsive heterogeneous catalysis is a powerful concept that unites the possibility for in situ regulation of the reaction parameter space with the enhanced recyclability of solid-state platforms. The presented work reports the first example of a light-responsive heterogeneous catalyst for a three-component coupling reaction that relies on photochromic-molecule-directed modulation of the copper oxidation states in metal-organic frameworks (MOFs) via a stimuli-responsive spiropyran derivative covalently integrated within a host scaffold. Comprehensive spectroscopic analysis, supported by theoretical modeling, establishes the first correlations among isomerization of a photochromic moiety, modulation of metal oxidation states in MOF metal nodes, and the material's overall chemical reactivity in a three-component coupling reaction. Moreover, this work provides the first confirmation that the photophysical performance of integrated spiropyran derivatives is maintained after exposure to selected reaction conditions, leading to material recyclability while preserving its catalytic activity. The developed photochromic MOF-based catalyst promoted the synthesis of 12 different compounds, including commodity chemicals and pharmaceuticals, with near-quantitative yields under mild reaction conditions while maintaining crystallinity and catalytic performance over multiple reaction cycles. Overall, these findings unlock a novel avenue toward noninvasive control of chemical reactivity via on-demand metal oxidation state modulation, establishing a new design principle for adaptive catalytic systems and offering a transformative pathway toward controllable chemical synthesis.

Conjugated thiophene-based diboronate esters, 1-4, were synthesized to investigate how substituents on catechol alter the Lewis acidity and accessibility to boron, and influence binding interactions with low molecular weight Lewis basic amines. Crystallographic analysis indicated that both boron centres bind analyte and that Lewis base coordination induces deplanarization of the conjugated system. Spectroscopic studies demonstrate that amine binding disrupts conjugation, producing distinct and reproducible optical responses that depend on analyte basicity and structure, with association constants in organic solvent ranging from 103 to 106 M-1. Quantitative binding analyses indicate strong negative cooperativity between the two boron sites. These results establish design principles for cross-reactive optical sensor arrays capable of differentiating volatile amines relevant to environmental monitoring, food quality assessment, and biomedical diagnostics.

Wadsley-Roth (WR) materials are candidate anode materials for lithium-ion batteries due to their unique and open structure that often enables fast lithium diffusion. We report the synthesis and electrochemistry of a quaternary T[3 × 3] WR compound, Mo0.92TiTa8.08O25. This tetragonal (I4/m) compound was synthesized in single-crystal form and has lattice parameters of a = 15.7326(4), b = 15.7326(4), and c = 3.8206(10) Å and a unit cell volume of 945.65(5) Å3. For property measurements, bulk polycrystalline samples were prepared via the conventional solid-state synthesis route. The powder was used in lithium half-cells as an active material to evaluate its electrochemical properties. A reversible lithiation capacity of 846 mA h cm-3 was obtained at a current density of 0.1C. Lithium diffusion coefficients were measured using intermittent current interruption where the parabolic trends with lithiation extent were consistent with lithium ordering. The corresponding capacity-weighted average diffusivity of 4.78 × 10-19 m2 s-1 was 31× lower than the closely related T[3 × 3] VTa9O25, indicating hindered diffusion. Mo K edge EXAFS confirmed the T-type phase with a 4-fold Mo coordination (CN = 3.85), and Ta L3 XANES revealed less distortion of the (Ta/Ti)O6 octahedral sites when compared to the single-occupancy sites in VTa9O25. To explain this substantially slower diffusion observed in Mo0.92TiTa8.08O25, calculations revealed trapping of Li in sites near the tetrahedra due to large activation barriers and also identified a restrictive multistep Li hopping path for transition from horizontal to vertical window sites when near octahedral Ti. Overall, this work demonstrates that the chemical composition strongly influences Li diffusion in a variety of ways in WR compounds.

Sodium barium lutetium borate NaBaLu(BO3)2 crystals were synthesized using a high-temperature solution method. The crystal structure of this layered orthoborate is described and corresponds to that of an extensive orthoborates family, NaBaR(BO3)2 (R = Sc, Y, Yb, Tb-Lu). NaBaLu(BO3)2 was doped by Eu3+ and Tb3+ to explore its performance as a host material and to investigate the luminescent properties of the Eu3+ and Tb3+ doped materials. The emission spectra of the NaBaLu(BO3)2:Ln (Ln = Eu, Tb) crystals are presented. The most intensive peak of NaBaLu(BO3)2:Eu, located at 592 nm, corresponds to the red emission, while the most intensive peak of NaBaLu(BO3)2:Tb, located at 550 nm, is associated with green emission.

The discovery of new compounds is essential for the ongoing development of materials science. Herein, we report a novel quaternary, three-dimensional thioborate (Nd3SiS7)2(Nd3SiS4BS3) structure, synthesized via the flux assisted facile boron chalcogen mixture method. Single crystal X-ray diffraction was used to determine the crystal structure. The compound crystallizes in the hexagonal crystal system in the noncentrosymmetric space group P63. The structure is charge-balanced with a 1/3 occupancy of the boron site. The effective magnetic moment of (Nd3SiS7)2(Nd3SiS4BS3) determined from the temperature dependence of the magnetic susceptibility over the 2 – 300 K temperature range is 6.21 μB/F. U. The susceptibility plot reveals paramagnetic behavior. (Nd3SiS7)2(Nd3SiS4BS3) exhibits a semiconducting band gap of 2.3(1) eV from UV-vis diffuse reflectance measurement, and density functional theory (DFT) calculations confirm its semiconducting character with a calculated band gap of approximately 2.02 eV.