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In this article, the direct electrochemical behavior of nitrite at a Au nanoparticles (AuNPs)/carbon paper (CP) electrode made using a rapid electrochemical deposition method was investigated. The morphology of the AuNPs on the CP surface was characterized by scanning electron microscopy (SEM). The existence of the Au element was verified by energy dispersive spectroscopy (EDS). The crystal structure of the AuNPs was verified by X-ray diffraction (XRD). Cyclic voltammetry (CV) was applied to evaluate the electrochemical behavior of nitrite oxidation. Under the optimum conditions, the AuNPs/CP electrode exhibited a very strong response to nitrite; the oxidation peak current linearly increased with increasing nitrite in the ranges of 1 μM to 30 μM and 40 μM to 100 μM with correlation coefficients of 0.99883 and 0.99789, and a low detection limit of 0.093 μM. The suggested sensor demonstrated high sensitivity, good reproducibility and good recovery. [ABSTRACT FROM AUTHOR]

This paper explores the findings on the structures and physicochemical properties of titanium-oxo complexes (TOCs) stabilized by 9-hydroxy-9-fluorenecarboxylate ligands. Two complexes, with the overall formulas [Ti4O(OiPr)10(O3C14H8)2] (1) and [Ti6O4(OiPr)2(O3C14H8)4(O2CEt)6] (2), have been synthesized. The structures of the isolated crystals (1 and 2) were determined using single-crystal X-ray diffraction. Molecular structure analysis of the crystals also employed vibrational spectroscopic techniques (IR and Raman), UV--Vis diffuse reflectance spectroscopy (UV-Vis-DRS), and powder X-ray diffraction (XRD). Density functional theory (DFT) was utilized to elucidate the electronic structures of these complexes. Furthermore, the theoretical charge distribution in 1 and 2 and their reactivity were calculated. The results of these investigations suggest that the reactivity of 2 is significantly greater than that of 1. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (gCN) has shown great potential in photocatalysis. Developing suitable cocatalysts is a critical way to enhance gCN's photocatalytic performance. In this paper cobalt–nickel bimetallic phosphide (CoNiP) was used as a cocatalyst to modify gCN. A gCN/CoNiP composite was successfully prepared by a simple hydrothermal method. XRD, XPS, SEM, UV-vis DRS, and PL characterization studies showed that a Schottky junction-like structure was constructed between gCN and CoNiP, which intensified the visible light response, enhanced the charge transfer rate and prohibited the recombination of photogenerated carriers, thus significantly improving gCN photocatalytic activity. Under simulated sunlight, the removal efficiency of methylene blue (10 mg L−1) was 97.8% by 120 min of irradiation, 44.6% higher than that of gCN. The quenching experiment showed that ˙O2−, ˙OH and h+ were the main active species. Based on the above points, the possible mechanism of photocatalysis was deduced. [ABSTRACT FROM AUTHOR]

This study presents an electrochemical procedure for synthesizing graphene oxide (GO) nanosheets in a diluted acidic medium (0.05 M), featuring 100% synthesis yield. Characterization results revealed that the synthesized GO in this approach exhibits a low XRD peak position (around 10°) and a C/O ratio of 2.9, offering higher surface functionality than conventional electrochemical methods reported in the literature. We also demonstrated the tunability of the GO's surface functionality by manipulating the synthesis parameters, such as electrolyte concentration and synthesis time, offering flexibility that surpasses the constraints often seen in chemical methods. Additionally, it was observed that assembling the current GO nanosheets into diverse microscopic (e.g., layered and porous) and macroscopic (e.g., paper and aerogel) structures results in distinctive characteristics and properties. Electromagnetic interference (EMI) shields with tunable specific EMI shielding effectiveness (SSE/t) and shielding mechanisms have been devised by fine-tuning the synthesis and processing methodologies. Excellent SSE/t ranging from 5000 dB cm2 g−1 for compact to 2000 dB cm2 g−1 for porous shields has been achieved, unraveling the importance of multi-scale materials design for the performance of the final products. [ABSTRACT FROM AUTHOR]

Materials based on cellulose are predicted to be of great importance in a sustainable society. However, for materials such as paper to replace materials with a higher ecological footprint, they need to be strong, ductile, provide a gas barrier, and, sometimes, also be transparent. Improved properties, or even novel properties, are also important for use outside the conventional markets. This paper describes how cellulose fibres partly derivatised to dialcohol cellulose can be used to fabricate high-density materials by conventional papermaking techniques that simultaneously display all the above-mentioned features. The materials produced were characterised with respect to X-ray diffraction, dynamic mechanical thermal behaviour, visual appearance, oxygen permeability and tensile properties. The highest degree of modification studied, resulted in a material with thermoplastic features, a tensile strength of 57 MPa, a strain-at-break of 44% and an oxygen permeability at 80% RH of 23 ml μm (m2 kPa 24 h)−1. At a thickness of 125 μm, these films have a total light transmittance of 78% (87% haze). However, by hot pressing the film for 2 min at 150 °C under a pressure of 16 MPa, and thereby increasing the density, the total transmittance increases to 89% (23% haze). The hot pressing can also be used to fuse individual pieces together, which is useful in many modern packaging applications. Altogether, this work shows how chemical modification of cellulose fibres can be used to induce novel properties and improve the range of application, and consequently provide an interesting bio-based material with a good potential to replace less sustainable materials. [ABSTRACT FROM AUTHOR]

Chiral surfaces are an object of interest due to their application in catalysis, separation and sensors. Such surfaces can exhibit chirality on the molecular or supramolecular level. Previously, we have studied the thermodynamic features of adsorption on non-porous surfaces with supramolecular chirality. However, for their application in enantiomer separation, enantioselectivity and capacity should be greater. Porous adsorbents are promising for this purpose. In this work, the enantioselectivity of copper borophosphate LiCu2[BP2O8(OH)2] was studied. This zeotype material was obtained by hydrothermal synthesis without any source of chirality. Supramolecular chirality was achieved by spontaneous symmetry breaking via Viedma ripening. XRD and SEM were used to prove the synthesis accuracy. Enantioselectivity during adsorption was studied using the adsorption isotherms of α-pinene and limonene enantiomer analysis. The experimental isotherms were approximated by Langmuir, Dubinin–Radushkevich, Freundlich and Fowler–Guggenheim equations. The t-test was used to prove the reliability of the differences in enantiomer adsorption. The isosteric heats of adsorption were calculated from the adsorption isotherms. The data obtained have shown the ability of the LiCu2[BP2O8(OH)2] surface to recognize both α-pinene and limonene enantiomers. The molecules of α-pinenes adsorbed without pores, with the maximum enantioselectivity coefficient of 1.23 at 80 °C. Limonene molecules adsorbed in pore volume as single molecules or 1D chains. This phenomenon was proved by analysis of isosteric heats. The enantioselectivity of copper borophosphate to limonenes and α-pinenes was similar. The ability of pores with supramolecular chirality (and without molecular chirality) to recognize enantiomers was discovered in this paper for the first time. [ABSTRACT FROM AUTHOR]

In general, β-Ga2O3 films with (2¯01) out-of-orientation have been widely obtained and reported on (0001) sapphire substrates by various growth methods. In this paper, the unusual (3¯10)-oriented β-Ga2O3 films have been epitaxially grown on (0001) sapphire substrates with high crystal-quality under Ga-rich conditions by halide vapor phase epitaxy (HVPE). The out-of-plane epitaxial relationship as (3¯10) β-Ga2O3//(0001) α-Al2O3 has been confirmed by XRD and HRTEM analysis. Under most growth conditions, β-Ga2O3 films exhibit the coexistence of (3¯10) and (2¯01) out-of-plane orientation domains, and increasing the growth temperatures and HCl flow-rates can enhance the growth of (3¯10)-oriented β-Ga2O3. Off-angled (0001) sapphire substrates with off-angles (Δa) toward 〈112¯0〉 have been introduced to control the in-plane domains. It was indicated that the (2¯01)-oriented domains have been gradually eliminated with increasing the off-angles, and pure (3¯10)-oriented β-Ga2O3 films with the best crystal quality reported so far have been obtained while the off-angle was ∼7°. The decrease of the domain boundaries and defects caused by the in-plane rotational domains have led to the improvement of the crystal quality of the as-grown films. [ABSTRACT FROM AUTHOR]

In this paper, in order to solve the problem of more impurities and less functional groups on the surface of sludge-based biochar, phosphoric acid and chitosan were used to co-modify sludge-based biochar (CS/SBC-H3PO4) to enhance the removal of Cr(VI). CS/SBC-H3PO4 was characterized using SEM, XRD, FT-IR spectroscopy and XPS. When the initial concentration of Cr(VI) solution was 100 mg L−1, the pH was 2.0, and the dosage of adsorbent was 50 mg, the Cr(VI) removal rate of CS/SBC-H3PO4 was 89.70%. The adsorption process of Cr(VI) by CS/SBC-H3PO4 was spontaneous and heat-absorbing, and was dominated by monolayer chemisorption, which followed the quasi-second-order kinetic model and Langmuir adsorption isotherm model, and its maximum adsorption capacity was 201.93 mg g−1 at 298 K. The removal mechanism of Cr(VI) by CS/SBC-H3PO4 is electrostatic adsorption, reduction and complexation. In detail, CS/SBC-H3PO4 electrostatically adsorbs Cr(VI) through surface amino protonation, and then reduces Cr(VI) to Cr(III) through –NH3+ and O–H groups to generate –NO2, C–O and C＝O groups. Finally, Cr(III) is complexed with the C＝O group. [ABSTRACT FROM AUTHOR]

Rare-earth doped phosphors have received growing interest in the luminescence field, and hold great potential for lighting and display backlight applications. Nonetheless, the practical implementation of white light-emitting diodes requires the development of a cost-effective and high-performance red phosphor, which is still a significant challenge. In this paper, Eu3+ doped Ba3Na0.32Nb6O12(Si2O7)2 red phosphors were prepared using a high-temperature solid-state method. The structure and phase purity of the samples were analyzed in detail by powder X-ray diffraction (XRD), structure refinement and energy dispersive spectroscopy analysis. Under 395 nm excitation, the phosphor exhibited an intense red emission due to the 5D0 → 7FJ (J = 1, 2, 3, 4) transitions. Through decay curve measurements, it is found that the decay time corresponding to the double-exponential equation decreased with the increase of activator concentration. Theoretical calculations showed that the quadrupole–quadrupole interaction played a dominant role in concentration quenching. The CIE chromaticity coordinates of the phosphor were (0.6436, 0.3556) and the color purity reached 92.07%, indicating that the sample has high color purity. In addition, the temperature-dependent intensity was investigated in detail. The results demonstrated that Ba3Na0.32Nb6O12(Si2O7)2:Eu3+ is a potential red-emitting phosphor for near-ultraviolet based white light-emitting diodes. [ABSTRACT FROM AUTHOR]

The high temperature stability of zirconia crystals is improved by regulating the content of the stabilizer Y2O3. Cubic zirconia crystals with thermal stability are one of the most active academic research areas for zirconia crystal materials. Nonetheless, the reason for the discoloration of blue cubic zirconia at high temperatures was not determined. In this paper, the spectra of yttria-stabilized zirconia (YSZ) were investigated, and the local structure regulation was carried out to determine the reasons for the colour instability of crystals at high temperatures. Two kinds of blue cubic zirconia samples with different ZrO2–Y2O3 ratios were heated at 800 °C for 1 hour in an air atmosphere. The structure, optical characteristics, and electron binding energy of cubic zirconia crystals with different ratios before and after heating were compared. Sample A changed colour, while sample B remained unchanged. The amount of Y2O3 stabilizers in sample A is three times higher than that in sample B. The significant shift in the absorption cut-off edge of sample A after heating indicates a reduction in the crystal bandgap. The high temperature discoloration of the crystals is attributed to an increase in oxygen vacancies. The study of XPS, XRD, and Raman showed an increase in the concentration of oxygen vacancies in sample A after heating. The thermoluminescence spectra indicate the depth of oxygen vacancy defects and the increase in defect concentration after heating. [ABSTRACT FROM AUTHOR]

A novel pyridine-based difluoroboron compound containing a triphenylamine moiety was designed and synthesized. It exhibited intramolecular charge transfer features and aggregation-induced emission enhancement (AIEE) activity, as well as reversible mechanofluorochromic behavior upon grinding–fuming. The photophysical properties in solutions were explained by molecular simulation, and the results of XRD patterns and X-ray single crystal analyses illustrated that the switching of crystalline–amorphous states and the planarization of the molecular conformation in the solid state upon grinding gave rise to mechanofluorochromic behavior. Additionally, under 365 nm UV light, this compound was successfully used for latent fingerprint visualization testing due to its excellent AIEE activity, and inkless writing testing due to its solid-state color with high brightness and contrast upon grinding–fuming. [ABSTRACT FROM AUTHOR]

[MoV2 O2S2]2+-based thiosemicarbazone complexes appear as very promising molecules for biological applications due to the intrinsic properties of their components. This paper deals with the synthesis and characterization of six coordination complexes obtained by the reaction of [MoV2 O2S2]2+ clusters with bisthiosemicarbazone ligands that contain flexible or rigid spacers between the two thiosemicarbazone units. Interestingly, structural characterization by single-crystal X-ray diffraction, MALDI-TOF MS technique and NMR spectroscopy revealed that the nuclearity of the complex is controlled by the nature of the spacer between the thiosemicarbazone units. Binuclear complexes, namely [MoV2 O2S2(L1-3)], are isolated with flexible spacers while tetranuclear complexes [(MoV² O2S2)2(L4-6)2] are formed when the bisthiosemicarbazone ligands are built on rigid spacers. [ABSTRACT FROM AUTHOR]

The fact that the polymorphic outcome of crystallization is the result of the interplay between the relative thermodynamic stability and nucleation kinetics is well known. This paper presents the synthesis of 2,5-bis(3-bromophenyl)furan (MBPF), for which three polymorphic structures were obtained. The studies included: investigations of three polymorphic structures of this compound using single crystal X-ray diffraction, UV–Vis spectroscopy, circular dichroism spectroscopy, and theoretical approaches. The most important experimental result is the solvent effect on the MBPF conformation stability and in consequence on the crystal growth of the metastable phase. [ABSTRACT FROM AUTHOR]

Hydrothermal preparation was used to create stable luminous sulfur quantum dots (SQDs), and XRD, XPS, TEM, and FTIR analyses were used to assess their structural and morphological characteristics. With an average size of 5.5 2.0 nm, the SQDs had an S8 monoclinic crystal structure. The SQDs' 415 nm excitation-independent emission at an excitation wavelength of 342 nm was discovered by optical characterization. Nitrophenols (4- and 2-nitrophenol) having detection limits of 46 and 171 nM, respectively, were successfully detected using high quantum yield (72%) SQDs. Real sample analysis has been conducted with bottled, tap, and river water. The supporting investigation analyzed the fluorescence quenching mechanism and highlighted the probable static quenching phenomenon. SQDs are also an anti-counterfeiting material because of their high luminescence characteristics and have been successfully used as fluorescent ink. [ABSTRACT FROM AUTHOR]

Transition metal tellurides (TMTes) have received extensive attention for high specific energy sodium-ion batteries (SIBs) due to their high volumetric specific capacity. However, the continuous capacity attenuation arising from the huge volumetric strain during sodiation/desodiation impedes practical applications. Here, we report a "sandwich-type" carbon confinement strategy that entraps cobalt ditelluride (CoTe2) nanocrystals between two carbon layers. Porous cellulose-derived fibres were employed as the inner carbon framework to construct fast conductive circuits and provide an abundant site for anchoring CoTe2 nanocrystals. Polyvinylpyrrolidone (PVP)-derived carbon layers act as carbon armour to encapsulate CoTe2 nanocrystals, inhibiting their volume change and structural pulverization during repeated sodium intercalation/deintercalation. Benefiting from the exquisite structural design, the N-C@CoTe2@C electrode exhibits excellent cycling stability for over 3000 cycles at 2.0 A g−1 and rate performance (113.8 mA h g−1 at 5.0 A g−1). Moreover, ex situ XRD/TEM and kinetic tests revealed a multistep conversion reaction mechanism and a battery-capacitive dual-model Na-storage process. This work provides a new perspective on the development of low-cost and straightforward techniques for fabricating long-life commercial SIB anode materials. [ABSTRACT FROM AUTHOR]

In this paper, we report the synthesis methodology of a series of molybdate-intercalated hydrotalcite-like materials and their catalytic applications for the esterification of biomass-derived levulinic acid. A simple hydrothermal method was used to synthesize molybdate-intercalated MgFe, MgAl, and MgCr hydrotalcites in the presence of an ammonia solution as a hydrolyzing agent. The intercalation of molybdate was confirmed via X-ray diffraction (XRD) studies based on line broadening in the XRD pattern and peaks characteristic of a layered hydrotalcite structure with short-range ordering were observed. The introduction of the molybdate species resulted in strong Lewis-acidic sites, as evident from FT-IR pyridine desorption and temperature-programmed desorption studies. The resulting material exhibited a significant activity for the esterification of the biomass-derived levulinic acid. The reaction conditions were systematically optimized. The molybdate-intercalated magnesium iron hydrotalcite exhibited 93% conversion of levulinic acid to butyl levulinate (120 °C, 4 h) with 95% selectivity. Good recyclability of the catalysts was demonstrated using recyclability studies, in which the catalysts showed excellent stability and high conversion even after five cycles. [ABSTRACT FROM AUTHOR]

Herein, a simple in situ hydrothermal carbonization (HTC) approach has been used to synthesize different ratios of carbon-incorporated nickel cobaltite nanocomposites, denoted as NiCo2O4/C (Dx) (where x = 1, 2, 5, and 10, representing the molar ratio of dextrose to nickel precursor). The prepared nanomaterials were further characterized using XRD, SEM, TEM, Raman, FT-IR, BET, and XPS techniques and subsequently subjected to supercapacitor (SC) studies using 3 M KOH as the electrolyte. In the three-electrode SC studies, NiCo2O4/C (D2) showed a superior specific capacitance of 736 F g−1 at 1 A g−1 in comparison with pure NiCo2O4 (307 F g−1) and carbon nanospheres (CNS, 52 F g−1), with appreciable cycling stability, retaining about 85% of capacity up to 1000 cycles. Furthermore, in the two-electrode SC studies for NiCo2O4/C (D2) at 1 A g−1, the asymmetric configuration exhibited twice the energy density (20.3 W h kg−1) and power density (406 W kg−1) compared to the symmetric configuration, due to the hybrid EDLC–pseudocapacitive mechanism. In contrast, the symmetric configuration showed lower energy density (13.5 W h kg−1) and power density (213 W kg−1) owing to pseudocapacitive behavior alone. This noted synergistic enhancement effect on the supercapacitor performance of the NiCo2O4/C (D2) nanocomposite can be ascribed to the incorporation of optimal carbon content into NiCo2O4 to facilitate more electroactive sites for charge storage compared to pure NiCo2O4 and CNS. This kind of tuning of the carbon ratios in the metal oxide/carbon nanocomposites through the in situ HTC approach and tailoring the symmetric/asymmetric SC device configurations will efficiently deliver a promising SC in the near future. [ABSTRACT FROM AUTHOR]

BiOCl has garnered considerable attention recently. However, its relatively wide bandgap and poor separation efficiency of charge carriers limit its application in the visible light range. Introducing oxygen vacancies (OVs) and constructing heterojunctions are both considered as viable modification approaches. In this study, oxygen vacancy-rich BiOCl/Bi24O31Cl10 heterojunctions were synthesized using glycine as the fuel by a one-pot self-propagation method. Variations in the amount of fuel led to differences in OV concentration and heterojunction composition in the prepared samples. The XRD pattern, FTIR spectra and EDS confirmed the formation of BiOCl/Bi24O31Cl10 heterojunctions. The XPS and ESR spectra proved the existence of oxygen vacancies. The BET results showed that the sample prepared with an appropriate amount of glycine exhibited a larger specific surface area. The most effective OVs-BiOCl/Bi24O31Cl10 composite demonstrated improvements in degrading rhodamine B (RhB), showing 8.09 and 17.96 times greater efficiency compared to BiOCl and Bi24O31Cl10, respectively. It achieved 93% dye degradation within 30 minutes. [ABSTRACT FROM AUTHOR]

This research article introduced a novel one-pot method for synthesizing hydrogels, utilizing iron ions (Fe3+) and guar gum succinate (GGS) as cross-linkers. These hydrogels were characterized as cross-linked networks, with hydrogen bonds forming a sacrificial network and coordination bonds serving as the primary network. The reversible nature of these networks was attributed to the hydrogels' exceptional toughness and remarkable self-healing properties. The hydrogel's chemical structure was confirmed through FTIR spectroscopy. XRD analysis highlighted the disruption of the crystalline nature of GGS upon cross-linking with Fe3+. By controlling the Fe3+ concentration, the hydrogels' mechanical properties were tailored. Rheological measurements demonstrated mechanical and self-healing properties, while swelling studies revealed pH-dependent behavior. In vitro studies showed the hydrogels' significant anti-proliferative effect against U-87MG (human glioblastoma) cancer cells, while remaining biocompatible with normal cell lines (HEK-293). These results indicated the potential application of these hydrogels in advancing cancer treatment strategies. [ABSTRACT FROM AUTHOR]

Er3+/Yb3+ doped YVO4 and GdVO4 phosphors were prepared through the combustion technique and were characterized through various techniques. XRD has revealed a tetragonal structure for YVO4 and GdVO4 phosphors. The 980 nm excited upconversion emission has resulted in intense green upconversion emission from both samples. However, the GdVO4 sample has shown higher emission intensity. Photoacoustic heat generation in samples has been studied using the same 980 nm excitation, and in this case, the YVO4 phosphor has shown higher heat generation. The YVO4 phosphor again has shown lower heat dissipation and, hence, higher photo-thermal conversion efficiency upon irradiation of the sample. [ABSTRACT FROM AUTHOR]

We report a generalized route for synthesizing pure SnO2 and Cu (1 and 3 at%) doped SnO2 at room temperature with crystallite size in a nanometer range of 1.0–3.0 nm using CuCl2, nitric acid and Sn metal. The structural properties of these samples were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The open system was used to monitor heat generation. Thin films of SnO2 and SnO2:xCu nanocrystallites were prepared using a mixture of surfactant (docusate sodium salt), SnO2, water and cyclohexane. H2S sensing at room temperature was performed. The Cu-doped SnO2 sample showed higher sensitivity than pure SnO2, and its sensitivity was more than that of the reported ones. [ABSTRACT FROM AUTHOR]

Treating conic tetra-para-ethylacetato-calix[4]arene (1) with 2.2 equivalents of K2CO3 and 4 equivalents of 6-bromomethyl-6′-methyl-2,2′-bipyridine affords the expected fully substituted podand, mainly in its 1,3-alternate conformation (2). This tube-like bipyridyl derivative 2 was subjected to complexation studies with CoCl2·6H2O to give a blue tetra cobalt(II) complex species (3). This complex displays a unique group of 6 aromatic bipyridyl 1H-NMR resonance signals demonstrating its high symmetry, while X-ray diffraction studies showed the presence of 3 expected tetrahedral bpy(CoCl2) units and 1 original trigonal bipyramidal unit involving the adjunction of a fifth ligand assumed to be H2O that could participate in the crystal scaffold. [ABSTRACT FROM AUTHOR]

Adducts of sterically hindered tellurium catecholate Te(Cat36)2 (Cat36 = 3,6-di-tert-butyl-catecholate) with diimine ligands were isolated and characterized by means of single crystal X-ray diffraction along with IR, UV-vis-NIR and NMR (1H, 125Te) spectroscopy. Adducts with 1,10-phenanthroline (phen) and 5,6-epoxy-5,6-dihydro-[1,10]phenanthroline (phenO) feature a very rare μ-κ2N,N′:κ2N,N′-bridging coordination mode of diimines. The adduct with 2,2′-bipyrimidine (bpm) is dimeric with a μ-κ2N,N′:κ2N,N′-bridging coordination mode of bpm, while with 4,7-dimethyl-1,10-phenanthroline (phenMe2) a dimer is formed due to Te-(η6-C6) contacts. Te⋯N and Te⋯C interactions between Te(Cat36)2 and the diimines were found to be attractive and non-covalent (DFT and QTAIM). In accordance with the weakness of Te⋯N interactions, no ligand-to-ligand charge transfer (LLCT) bands were observed in the electronic spectra of the adducts. [ABSTRACT FROM AUTHOR]

This work investigates the role of stable (sing-phased) and unstable (bi-phased) lattice structures in controlling the magnetic spin order and electronic properties in Co-rich ferrites of compositions Co1.25Fe1.75O4 and Co2.25Fe0.75O4. The material was synthesized via the chemical reaction of metal (Co and Fe) nitrates in an alkaline medium and post-heat treatment. The XRD patterns of Co1.25Fe1.75O4 showed a single-phased structure upon heat treatment in the temperature range of 200–900 °C, whereas Co2.25Fe0.75O4 showed a single-phased structure at 900 °C and bi-phased structure at a low heating temperature range of 200–800 °C. The thermally induced irreversibility (non-equilibrium) effect was observed in the lattice structure, magnetic spin order and electrical conductivity. The lattice structure at the (local) microscopic scale showed a more or less metastable state and coexistence of mixed-charge states of Co and Fe ions, irrespective of the single or bi-phased structure. The magnetic and electronic responses are found to be sensitive enough to detect local level non-equilibrium (metastable) states in non-equilibrium and equilibrium crystalline phases seen from XRD patterns. [ABSTRACT FROM AUTHOR]

Fumed alumina from the combustion of AlCl3 produced nano particles with specific areas from 30 to 220 m² g-1 (BET) which were characterized by powder X-ray diffraction, 27Al solid-state NMR and transmission electron microscopy. During the short-lived synthesis, highly disordered γ-alumina progressively transforms into a mixture of δ and θ-alumina. For the γ-alumina particles, only for particles with the highest specific area a significant amount of five-coordinated Al can be found which is only partially located in the particle surface. Water can be bound reversibly and increases the coordination number of aluminium atoms in the particle surface. For the well-crystallized mixture of δ and θ-alumina, high resolution and high S/N powder XRD pattern features a large number of superstructure reflections along with the commonly observed diffuse reflections. 27Al MQMAS NMR provides a total of 8 crystallographic sites with an unusually high resolution in the tetrahedral region, with 4 distinct AlO4 sites pertaining to the δ phase alone. The results suggest that the δ-alumina phase produced in this process can be described as an ordered structure. [ABSTRACT FROM AUTHOR]

Two phenothiazine derivatives, PTCNB and PTCNTBB, were designed and synthesized to confirm whether triaryl-substituted phenothiazine has mechanofluorochromic (MFC) properties and investigate the impact of tert-butyl (t-butyl) as a steric hindrance group on the molecular response to force stimuli. It was observed that the introduction of the t-butyl moiety did not significantly alter the molecular photophysical properties in the solution state due to its minimal effect on molecular π-conjugation. However, the presence of t-butyl strongly influenced their photoluminescence behavior and force-stimulus response in the solid state. PTCNB without t-butyl exhibited orange fluorescence in its pristine solid, which transformed into red fluorescence upon grinding, accompanied by a spectral shift of 23 nm. Conversely, PTCNTBB with t-butyl displayed green fluorescence in the as-synthesized solid and subsequently emitted orange fluorescence under force stimuli, demonstrating a more pronounced color variation. The corresponding spectral shift value was measured to be 58 nm. Remarkably, both ground solids regained their original fluorescence colors after vapor fuming, indicating a reversible MFC process. XRD patterns suggested that the application of force stimuli disrupted the intermolecular ordered packing while the fuming process restored ordered stacking, leading to the recovery of fluorescence emission. Absorption spectral changes implied that the presence of t-butyl induced loose packing and weak π--π interactions in PTCNTBB's initial solid, resulting in a short-wavelength fluorescence. Under force stimuli, the intermolecular interaction between PTCNTBB molecules was significantly enhanced, leading to an obvious redshift in the fluorescence spectra. In contrast, due to the absence of bulky steric groups, intermolecular packing between PTCNB molecules was relatively dense in its pristine solid and then applying pressure did not cause significant changes in a π-packing arrangement; hence only a small spectral shift occurred. [ABSTRACT FROM AUTHOR]

CsPbBr3 crystals exhibit high photoelectric absorption, large carrier mobility, long carrier lifetimes, and notable stability at room temperature. With an intermediate bandgap of 2.3 eV, they allow the fabrication of stable photonic devices and show good application prospects in the field of nuclear radiation detection. Through the adjustment of the polycrystalline raw material synthesis, crucible shape design, and multiple growths, a high-quality CsPbBr3 crystal of Φ 50 mm x 80 mm with uniform and crack-free appearance was successfully grown by the vertical Bridgman method. The FWHM of the different crystalline planes was characterized by XRD rocking curves, which showed that the (010) plane has a narrower half peak width and higher crystallinity. Detectors with an Au/CsPbBr3/Au structure were fabricated by magnetron sputtering with Au electrodes of 2 mm in diameter, and the resistivity of the (100) crystal plane and (010) crystal plane was 2.5 x 109 Ω cm and 7.8 x 109 Ω cm, respectively. Under a 5 V bias, UV lamp bands and X-ray irradiation tests revealed that devices with the (010) plane had higher switching ratios and sensitivity, resulting in higher signal-to-noise ratios at lower X-ray doses. [ABSTRACT FROM AUTHOR]

Reactions of bromoantimonate(III) containing solutions with Br2 in the presence of different organic cations result in structurally highly diverse crystalline products readily forming halogen bonds (XBs). Herein, we add six new compounds to this palette using 1,n-bis(3-methylpyridinium)- or (4-methylpyridinium)alkane dications; the complexes were characterized using X-ray diffraction and thermogravimetric analysis (TGA). Further, we discuss all previous results in this field, including quantum chemistry investigation of the features of XBs in such compounds. [ABSTRACT FROM AUTHOR]

In this study, NiTiO3 nanoparticles supported on exfoliated montmorillonite K30 (MK30) were synthesised in an eco-friendly manner using ultrasonication and were used as a benign heterogeneous catalyst for the synthesis of 4-amino pyrimidine analogues in a microwave medium. The nature of the catalyst was investigated using various characterization techniques, including XRD, FT-IR, TGA, BET, FE-SEM, TEM, and XPS. The catalytic activity of the synthesised catalyst was examined, and 20% NiTiO3/MK30 at 25 wt% showed efficient catalytic activity with high yields compared to other loadings. Non-conventional microwave irradiation was used to carry out the reaction under mild conditions, resulting in a high conversion rate. The reaction was optimised with respect to the type and amount of the catalyst, temperature, solvent, and microwave power. The scope of the reaction was extended using various aldehyde derivatives, which also produced high yields. After 6 cycles, the recovered catalyst showed good catalytic activity, achieving high yields (88–95%) within 5 min. Mechanistic investigation of the reaction hypothesized the 1st step as the synthesis of arylidene malononitrile via Knoevenagel condensation of aldehyde and di-cyanomethane, followed by the Michael addition of acetamidine to arylidene malononitrile and aromatisation to produce 2-methyl-4-amino-pyrimidine-5-carbonitriles. This synthetic approach offers several advantages, including high yield, benign reaction conditions, short reaction time, straightforward work procedure, and catalyst reusability. [ABSTRACT FROM AUTHOR]

Visible-light active heterogeneous photocatalysts offer various advantages owing to their ability to exploit clean, renewable, and economically viable visible light as a driving force. This study aims to develop such photocatalysts by incorporating various loadings (10, 20, and 30 wt%) of bismuth tungstate (Bi2WO6 or BWO) into graphitic carbon nitride (g-C3N4 or CN) nanosheets. The CN nanosheets and BWO nanomaterials are synthesized using an eco-friendly hydrothermal method. The objective is to evaluate the photocatalytic activity of these catalysts for the Knoevenagel condensation reaction under 12 W blue LED light (low power), aiming to outperform the activity of pure CN. Various characterization methods, including XRD, UV-vis DRS, FTIR, PL, XPS, and TEM, are employed to analyze the catalysts. The study specifically focuses on the performance of the various BWO loading percentages on CN nanosheets. Among those, 20 wt% BWO loaded CN achieves a yield of 80% with minimal activity decline over five recyclability cycles. Furthermore, this study identifies that BWO/CN follows a Z-scheme pathway, enhancing the photocatalytic performance and facilitating organic transformations. Scavenging experiments confirm the formation of radicals during photocatalysis, validating the proposed mechanism and providing crucial mechanistic insights. Ultimately, this research seeks to highlight BWO/CN as a promising, environmentally friendly photoactive substance with significant potential for effective photocatalytic use. To our knowledge, this is the first study to use BWO/CN catalysts for the Knoevenagel condensation reaction under blue LED irradiation. [ABSTRACT FROM AUTHOR]

New insights into 3D-oriented strain-induced crystallization of natural rubber/cellulose nanocrystal (NR/CNC) composites have been obtained by 2D wide-angle X-ray diffraction (2D-WAXD). Upon CNC content exceeding 10 wt%, the mechanical behavior of the material exhibits a yield point that resembles those observed in plastics. Taking into account the influence of filler content of CNCs and thickness, the three-dimensional orientation degree of NR crystallites can be quantitatively assessed. The formation of 3D NR crystallites can be established when the CNC content surpasses 10%, and concurrently, the degree of three-dimensional orientation of crystallites increases as thickness decreases. It was found that not only do CNCs enhance the confinement effect, leading to a decrease in the onset strain, but it is also beneficial for the formation of 3D-oriented strain-induced NR crystallites. The current study not only helps in the comprehensive understanding of the mechanism of 3D-oriented strain-induced NR crystallites by the constrained rigid filler network, but also provides the potential application of uniaxial tensile stretching in creating 3D functional materials. [ABSTRACT FROM AUTHOR]

Charge-neutral hexadecanuclear nanoclusters [Co16(OH)4(ib)20(thme)2(Hthme)2(H2O)6]·MeCN·4H2O (1) and [Co16(OH)4(ib)20(thmp)2(Hthmp)2(H2O)6]·MeCN·4H2O (2) have been prepared from the reaction of Co(II) isobutyrate (Co(ib)2) with 1,1,1-tris(hydroxymethyl)ethane (H3thme) or 1,1,1-tris(hydroxymethyl)propane (H3thmp) and comprehensively characterized. Single-crystal X-ray diffraction reveals that the common mixed-valent centrosymmetric {Co(II)14Co(III)2} core of 1 and 2 represents an unprecedented arrangement of two planar {Co7} disk-like fragments with a central Co(III) ion surrounded by six Co(II) ions connected by two additional Co(II) ions. The two {Co7} fragments are non-coplanar and lie in parallel planes separated by a distance of 2.772 Å, with two additional Co(II) centers between these planes. Hirshfeld surface (HS) analysis was used to gain additional insight into the interactions responsible for the packing of nanoclusters in the title compounds. Magnetic characterization of 1 revealed that the 14 Co(II) centers exhibit predominantly ferromagnetic exchange interactions, but some antiferromagnetic exchange pathways are also present. [ABSTRACT FROM AUTHOR]

Four new POM-based coordination complexes [Cu(TPP)2(CH3CN)2]2{[Cu(TPP)2]2(β-Mo8O26)}·2CH3CN (1) (TPP = triphenylphosphine), {[Ag(TPP)]2·[Ag(TPP)2]2·(β-Mo8O26)}·6DMF (2), {[Cu2(DPPM)2(CH3CN)]2(β-Mo8O26)}·2CH3CN·2DCM (3) (DPPM = bis(diphenylphosphino)methane), and {[Ag2(DPPM)2·(CH3CN)]2(β-Mo8O26)}·2CH3CN·2DCM (4) were prepared through the self-assembly of α-octamolybdates and the corresponding Cu/Ag phosphine building blocks. Single crystal X-ray diffraction reveals that compound 1 consists of two cations of [Cu(TPP)2(CH3CN)2]+ and one anion of {[Cu(TPP)2]2(β-Mo8O26)}2−; the anion of {[Cu(TPP)2]2(β-Mo8O26)}2− can be viewed in such a way that the central cluster of β-Mo8O26 are coordinated with two Cu(TPP)2 units via terminal oxygen atoms to form a linear trimer; compound 2 is a neutral cross-like pentamer which is made up of the central β-Mo8O26 coordinated with two equatorial Ag(TPP)2 units and two Ag(TPP) units above and below the β-Mo8O26 cluster via the terminal oxygen atoms; compounds 3 and 4 can be viewed as a trimer consisting of two binuclear metal clusters of {[Cu2(DPPM)2(CH3CN)]2}2+ or {[Ag2(DPPM)2(CH3CN)]2}2+ bridged by one β-Mo8O26 cluster via terminal oxygen atoms. Their structures are further evidenced by FT-IR and PXRD. TGA study indicates that the skeleton of compounds 1–4 is stable up to 250–290 °C and then a rapid weight loss followed. Their band gaps can be calculated (Eg value: 2.27 eV for 1, 3.14 eV for 2, 2.66 eV for 3, and 3.16 eV for 4) using the Tauc's method according to their solid state UV diffuse reflection spectra. Upon irradiation at 211 nm, compounds 1–4 exhibit a series of successive emissions around 360 nm, 380 nm and 400 nm, which demonstrate a similar solid state emission compared to their corresponding Cu/Ag phosphine building blocks. [ABSTRACT FROM AUTHOR]

In order to study the competition between halogen bond acceptor sites of multifunctional N,O,X-based halogen bond acceptors (X = S, O, N or π aromatic ring) we have synthesized a family of oxazole derivatives and cocrystallized them with selected iodoperfluorinated benzenes as halogen bond donors. Out of 28 combinations, 19 experiments yielded crystals suitable for single-crystal X-ray diffraction. Structural analysis revealed that in all of the obtained cocrystals the most prominent supramolecular interaction is the I⋯Noxazole halogen bond with relative shortening values of up to 18%, comparable to I⋯Npyridine halogen bond shortening values. The acceptors are ditopic in 10 cocrystals and form additional I⋯N, I⋯O or I⋯π halogen bonds. A majority of cocrystals feature one donor molecule per one acceptor molecule. In order to rank the acceptor sites and establish how the electrostatic potential differences impact the supramolecular landscape around these molecules, the values of molecular electrostatic potentials (MEPs) were calculated on their optimized geometries. These calculations were in agreement with experimental observations, since the best (most negative MEP value) acceptor binding site in the series of used oxazoles is the oxazole nitrogen atom. Depending on the difference between MEP values of the oxazole oxygen atom and the peripheral functionalities, additional halogen bonds could potentially be formed with one of these acceptor sites, leading to the formation of two different types of halogen-bonded supramolecular chains. [ABSTRACT FROM AUTHOR]

Continuous manufacturing of platform chemicals from lignocellulose is highly desirable for a fossil fuel independent future. We demonstrate highly selective production of para-xylene (pX) from ethylene and 2,5-dimethylfuran (DMF) in a packed bed microreactor using phosphorous-decorated zeolite beta (P-BEA), with pX selectivity up to 97% at 80% DMF conversion. We map the effect of reactor temperature, space velocity, concentration, gas-to-liquid ratio, and process pressure. Time-on-stream (TOS) and in situ regeneration studies show minimal productivity degradation over ∼5 h TOS and full productivity restoration upon regeneration for multiple cycles. Most non-selective Brønsted acidity occurs at low TOS and is attributed to the remaining trace Al bridge site. External mass transfer limitations are implicated at low space velocities. We combine the TOS data with NMR, XRD, and Raman to develop structure–performance insights into the catalyst behavior. A comparison with mesoporous P-supported materials illustrates that P-BEA is an excellent catalyst for size selectivity and long-term stability. [ABSTRACT FROM AUTHOR]

Graphite demand is increasing rapidly due to the popularity of electric vehicles (EVs) and mobile devices. Lithium-ion batteries (LIBs) are the power source of EVs and mobile devices and the anodes of LIBs are mostly made of graphite, which is currently produced in an unsustainable and costly manner. For the first time, battery-grade biographite is produced from a renewable and sustainable precursor, biomass-derived pyrolysis oil, using iron as the graphitizing catalyst. Considering battery-grade graphite production at scale, pyrolysis oil offers several advantages as feedstock over biomass in terms of higher carbon density, low inorganics, easy handling, and low transportation cost. Catalytic graphitization of pyrolysis oil can be induced at low temperature (∼1100 °C). Herein, catalytic graphitization using iron powder was carried out under relatively moderate conditions (1500 °C) to reduce costs and environmental impact as compared to incumbent technologies. After graphitization, the residual catalyst was removed by refluxing the biographite + iron solid mixture with hydrochloric acid. The efficiency of iron removal was studied using the X-ray fluorescence (XRF) technique. The structural and morphological properties of biographites were assessed via X-ray diffraction (XRD), Raman spectroscopy, and high-resolution transmission electron microscopy (HR-TEM). The in situ XRD experiments provided a mechanistic understanding of the iron-catalyzed graphitization process. In addition, the effect of pyrolysis oil aging on the biographite crystalline structure was elucidated. The optimal biographite sample demonstrated impressive electrochemical performance with a reversible capacity of 350 mA h g−1, an initial coulombic efficiency of 90.2%, and minimal capacity loss over 100 cycles when applied as an LIB anode, thereby making pyrolysis oil-derived biographite potentially competitive with commercially available battery-grade graphite. [ABSTRACT FROM AUTHOR]

We obtained crystals of novel supramolecular compounds with cucurbit[6]uril which contain aquanitrato complexes of mixed lanthanides. The supramolecular approach was used to produce compounds exhibiting multicolor emission. An X-ray diffraction study demonstrated that the compounds have the following compositions: [{Ln 10.5 Ln 20.5 (H2O)5(NO3)}2CB[6]](NO3)4·HNO3·nH2O (Ln1 = Eu, Ln2 = Pr (1), Nd (2), Sm (3), Gd (4), Tb (5) Dy (6), Er (8)), [{Ln 10.7 Ln 20.3 (H2O)5(NO3)}2CB[6]](NO3)4·HNO3·nH2O (Ln1 = Eu, Ln2 = Ho (7)) and 2[Ln 10.5 Ln 20.5 (H2O)8](NO3)3·CB[6]·2HNO3·mH2O (Ln1 = Eu, Ln2 = Yb (9)). The luminescence properties of compounds 1–9 were investigated in the solid state. The color purity of compound 6 is very close to zero, so it is well suited for white-light generation and can be used for WLED applications. A cool white LED device was fabricated by combining the supramolecular compound 6 and a UV LED chip (365 nm) at a voltage of 3.0 V; the CIE, CCT and CP were (0.328; 0.313), 5736 K and 2%, respectively. Compounds 5 and 6 have different glow colors when irradiated with different wavelengths; modulation of light emission in such compounds can be used to protect against counterfeiting. [ABSTRACT FROM AUTHOR]

New fluorinated dibenzo-1,2,5,6-tetrathiocines 1 and 2 were synthesized by a novel condensation of 1,2-disulfenyl chlorides under the influence of elemental Cu, and structurally defined in the solid state, solution, and gas phase by single-crystal XRD, variable-temperature 19F NMR and NOESY, and DFT calculations. Crystalline 1 and 2 exhibited the C2h chair and C2 twist molecular conformations, respectively. Unlike 1 displayed only C⋯S shortened intermolecular contacts, crystal structure of 2 featured F⋯π, F⋯F, F⋯S and S⋯S contacts. In toluene solutions at 296 K, both twist and chair conformers were observed in the ∼1 : 1 and ∼7 : 1 ratios for 1 and 2, respectively. For 1, the twist ↔ chair conformer interconversion was practically temperature-independent, and for 2 revealed ΔH ∼3.5 kJ mol−1 and ΔS ∼4.4 J K−1 mol−1. With DFT, the PESs for twist–chair transformation and twist–twist racemization were analyzed and the TSs exhibiting twist–halfchair and boat conformations, respectively, were found. Several additional stationary points on the PESs, corresponding to hidden intermediates and bifurcation points and featuring twistboat and halfchair conformations were detected. In chloroform solution under sunlight, 1 underwent 1,2,5,6-tetrathiocine → 1,2,3,6-tetrathiocine isomerization whose product was characterized by XRD. [ABSTRACT FROM AUTHOR]

Five cationic ruthenium(II) chelates with the generic formula [Ru(S2C·NHC)3](PF6)2 were readily obtained upon cleavage of the [RuCl2(p-cymene)]2 dimer with representative imidazol(in)ium-2-dithiocarboxylate zwitterions (NHC·CS2) in the presence of KPF6. The homoleptic complexes were fully characterized by various analytical techniques and the molecular structure of one of them was determined by single-crystal X-ray diffraction analysis. As expected, it featured an octahedral RuS6 core surrounded by three imidazol(in)ium rings and their nitrogen substituents. The robustness of the Ru–S bonds combined with the chelate effect of the κ2-S,S′-dithiocarboxylate units and the steric protection imparted by bulky 1,3-diarylimidazol(in)ium groups most likely accounted for the outstanding stability of these species in solution. Cyclic voltammetry showed that the five homoleptic complexes featured characteristic waves for a monoelectronic redox process corresponding to the RuIII/RuII couple with E1/2 values ranging between 0.97 and 1.27 V vs. Ag/AgCl. This half-wave potential was clearly dependent on the nature of their ancillary ligands as the evolution of the Ep,ox values roughly paralleled the basicity sequence of the NHCs used to prepare them, in line with the trends observed when monitoring the chemical shifts of the CS2− unit on 13C NMR spectroscopy and the CS2− asymmetric stretching vibration wavenumbers on IR spectroscopy. [ABSTRACT FROM AUTHOR]

Ferrocene-substituted carbenes have emerged as attractive, redox-active ligands. However, among the compounds studied to date, ferrocenylated 1,2,4-triazol-5-ylidenes, which are closely related to the archetypal imidazol-2-ylidenes, are still unknown. Here, we demonstrate that the triazolium salt [CHN(Me)NCHN(Fc)]I (2; Fc = ferrocenyl), obtained by alkylation of 4-ferrocenyl-4H-1,2,4-triazole (1) with MeI, reacts selectively with metal alkoxide/hydroxide precursors [(cod)Rh(OMe)]2 and [(IPr)Au(OH)] (cod = cycloocta-1,5-diene, IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) to produce the ferrocene-substituted 1,2,4-triazol-5-ylidene complexes [(cod)RhI{CN(Me)NCHN(Fc)}] and [(IPr)Au{CN(Me)NCHN(Fc)}]I in good yields. The complexes were characterised by NMR and IR spectroscopy, mass spectrometry, cyclic voltammetry, and single-crystal X-ray diffraction analysis. Density function theory (DFT) calculations were used to rationalise the electrochemical behaviour of the carbene complexes and to elucidate the bonding situation in these compounds. An analysis using intrinsic bond orbitals (IBOs) revealed that the 1,2,4-triazol-5-ylidene ligand exerted a strong trans influence and showed a synergistic stabilisation by the negative inductive and positive π-donor effects of the nitrogen atoms adjacent to the carbene carbon atom; these effects were enhanced by conjugation with the CH＝N bond at the exterior, similar to that in imidazol-2-ylidenes. [ABSTRACT FROM AUTHOR]

The photocatalytic hydrogen evolution half-reaction (HER) is a promising technology for meeting future energy demands. An excellent photocarrier separation is essential for the HER. Here, a CdS/ZnS composite (CZS) with a dual photocarrier separation channel has been synthesized using the epitaxial growth method to achieve this aim. XRD and TEM show that pre-adsorption of S2− on the CdS surface facilitates the conversion of CdS into ZnS with a larger solubility product, implying a good carrier transport channel between CdS and ZnS. Based on XPS, PL, and photo-deposition experiments, a dual-channel photocarrier separation mechanism has been proposed, which is the source of the great photocarrier separation, and thus the hydrogen evolution rate of the CZS-2 sample (22.05 mmol g−1 h−1) becomes 18.5 and 73.5 times higher than those of CdS and ZnS. The apparent quantum yield (AQY) of CZS-2 at 420 nm is 4.68%. [ABSTRACT FROM AUTHOR]

In this study, we demonstrate the successful synthesis of sulfur–MOF composites and their application in the Willgerodt–Kindler reaction. We showed that MIL-53(Al), CAU-10-H and MIL-101(Cr) encapsulate the sulfur without MOF decomposition by the melt-diffusion technique, whereas MIL-88A and MIL-101(Fe) were unable to form S@MOF composites. Various techniques, including XRD, SEM, EDS, and porometry, were used to characterize the synthesized S@MOF composites. The influence of MOF nature, temperature, reaction time and reagent ratio on the Willgerodt–Kindler reaction product formation was evaluated. The S@CAU-10-H composite led to the thiomorpholides from various arylaldehydes, acetophenones and propiophenones in 56–91% isolated yields. The reaction proceeds at near equimolar reactant concentrations. Product isolation is straightforward and does not require tedious chromatographic purification. The MOF was easily separated and reused in five runs, achieving a good performance without significant framework degradation. We postulate that the MOF has multiple roles, acting as a reaction medium, sulfur carrier, amine absorber and dehydration agent. [ABSTRACT FROM AUTHOR]

Dinuclear Au(I) complexes with bisphosphine ligands, namely [Au2Cl2(L)], where L = 4,6-bis(diphenylphosphino)pyrimidine (Au1) or 1,7-bis(di-o-tolylphosphinyl)-m-carborane (Au2), have been synthesized. The complexes were characterized by analytical and spectroscopic methods and their crystal structures were determined by X-ray diffraction analysis. Both complexes demonstrated photoluminescence in the solid state at 300 K when excited at 300–400 nm: from blue emission (∼400 nm) for Au1 to green emission (∼500 mn) for Au2. The lifetimes of the excited state were determined to be in the microsecond range, indicating the triplet nature of the emission levels. Preliminary bioactivity tests for complexes Au1 and Au2 in comparison with the respective ligands and cisplatin have been performed. [ABSTRACT FROM AUTHOR]

Herein, β-PbF2:Eu3+/K+ glass ceramics (GCs) were synthesized and characterized by X-ray diffraction (XRD), photoluminescence (PL) and decay curves. Based on the XRD analysis, it was inferred that Eu3+ and K+ ions were doped in the β-PbF2 lattice by substituting Pb2+ ions. Compared with the interstitial fluorine (Fi−) (Eu3+ + Fi− = Pb2+), K+ substitutional doping (Eu3+ + K+ = 2Pb2+) was the preferential charge-compensating mechanism with the introduction of K+ ions in the β-PbF2:Eu3+ GCs. Consequently, this is the first report on the anomalous emission of the 5D0/7F4 transition in β-PbF2:Eu3+ GCs. Based on this anomalous 5D0/7F4 transition, a new lattice site with D4d symmetry occupied by Eu3+ ions was proposed for the first time in β-PbF2:Eu3+ GCs. Moreover, according to the intensity ratio of I(5D0/7F0)/I(5D0/7F2) (I00/I02), I(5D0/7F2)/I(5D0/7F1) (I02/I01) and I(5D0/7F4)/I(5D0/7F1) (I04/I01), the breaking of the local lattice symmetry around the Eu3+ ions induced by K+ ions was demonstrated in detail. With the introduction of K+ ions in β-PbF2:Eu3+ GCs, the local lattice symmetry around the Eu3+ ions continued to decrease from Oh to D4d, C4v, C3v, C2v, and C1. Due to the effective charge-compensation of the K+ ions, we successfully realized the adjustment and enhancement of the reddish-orange emission from β-PbF2:Eu3+ GCs. Simultaneously, an example of Er3+-doped β-PbF2 GC was employed to demonstrate the spectral broadening effect of trivalent lanthanide ions (Ln3+) caused by lattice distortion and charge compensation. All these results provide insights to investigate the lattice structures of compounds and also guide researchers to design new emitting devices. [ABSTRACT FROM AUTHOR]

By introducing the d0 metal cation Mo6+ into phosphates, two new molybdophosphates, K2MgMoP2O10 and K3Mg2MoP3O14, were synthesized by spontaneous crystallization, and their structures were determined by single-crystal X-ray diffraction. K2MgMoP2O10 shows a two-dimensional layer composed of the uncommon eight-membered ring [Mo2P2O16] formed by [MoO6] and [PO4], while K3Mg2MoP3O14 shows isolated [MoP3O14] clusters composed of [MoO5] and [PO4]. K2MgMoP2O10 and K3Mg2MoP3O14 have UV cut-off wavelengths of 277 and 271 nm, respectively, which are significantly shorter than those of most recently published molybdophosphates. To the best of our acknowledge, K2MgMoP2O10 exhibits the largest birefringence (a calculated value of 0.187 at 546 nm) among reported alkali metal or alkaline earth metal molybdophosphates, which provides a way to explore new birefringent materials. First-principles analysis of the electronic structure shows that the large birefringence of K2MgMoP2O10 mainly originates from the [MoO6] units. [ABSTRACT FROM AUTHOR]

A rigid pentadentate chelating ligand (H2L) has been utilized to synthesize a series of octacoordinate mononuclear complexes, [Dy(L)(Ph3PO)(OOCR)] (where R = C6H5 (1), C(CH3)3 (2), CF3 (3)) and a dinuclear complex, [Dy2(L)2(Ph3PO)2{(OOC)2C6H4}] (4) based on the highly anisotropic Dy(III) ion. All the complexes were structurally characterized by single-crystal X-ray diffraction studies. The complexes were formed by the coordination action of the dianionic pentadentate ligand [L]2−, one phosphine oxide, and carboxylate ligands. DC and AC magnetic measurements were performed on 1–4. Complexes 1–4 show SMM behaviour, under zero DC field for 1 and 4, and under 500 Oe and 1000 Oe DC fields for 2 and 3 respectively, with thermally activated, Raman, and Raman and quantum tunnelling dominant relaxation mechanisms for 1 and 2, 3 and 4, respectively. [ABSTRACT FROM AUTHOR]

For the first time, the kinetics of decomposition of a metastable Ni0.50Ru0.50 solid solution was studied under isothermal conditions using in situ powder XRD. It has been shown that the main phase transformations occur in the temperature range of 500–600 °C according to a binodal mechanism, which is confirmed by HRTEM data. The resulting kinetic curves were approximated by a second-order reaction model and the activation energy of this process was calculated: 80 kJ mol−1. Additional calorimetric studies confirmed the obtained value. [ABSTRACT FROM AUTHOR]

Fluoroform (CHF3) is a byproduct of CHF2Cl with high global warming potential and long atmospheric lifetime, and its efficient utilization is a great challenge. The mechanochemical reaction between CHF3 and AlCl3 was studied for the first time, and the resultant ACFs (AlClxF3−x, x ≈ 0.1) were characterized by ion chromatography, X-ray photoelectron spectroscopy and X-ray diffraction. The reaction mechanism is revealed via experiments and DFT calculation. Here, the reactivity of AlCl3 is slightly higher than that of AlCl2F and AlClF2, while the reactivity of CHF2Cl and CHFCl2 is 2 to 6 orders of magnitude higher than that of CHF3. The reaction is self-accelerated until CHF3 is fully converted to CHCl3 and ACFs with controllable F-content. The present work provides a viable approach to convert CHF3 to CHCl3 and ACFs at ambient temperature and pressure, which is superior to the mainstream incineration technique with great energy demand and environmental pollution, and sacrifice of the precious F-resource. [ABSTRACT FROM AUTHOR]

In this paper, a Co--Fe LDO catalyst was prepared by combining K2Cr2O7 and Cr(NO3)3 to modify the LDH precursor. The catalytic activity of NOx and o-DCB was systematically studied, and the effect of gas composition on the catalytic activity was investigated. The prepared Cr (0.25)/Co--Fe LDO catalyst showed the best catalytic performance, with conversion efficiencies of NOx and o-DCB of 89.0% and 81.6% at 250 °C, respectively. The catalysts were characterized by XRD, BET, SEM, XPS, H2-TPD and NH3-TPD to explore the reaction activity. In addition, the interaction between NH3-SCR and o-DCB oxidation was investigated by changing the gas atmosphere. The results showed that the inhibition at low temperature (< 200 °C) could be attributed to the residues of the by-products of incomplete oxidation. The further oxidation of NO to NO2, and the dissociation of NH3 are the reasons for the mutual promotion of the two reactions in the middle and high temperature sections. Water vapor has little effect on the reaction and the introduction of SO2 will cause irreversible inactivation of the catalyst. [ABSTRACT FROM AUTHOR]

The second near-infrared window (NIR-II) in the range of 1000–1400 nm is ideal for in vivo imaging and sensing through reduced scattering, absorption, and autofluorescence. However, there are only a few nanophosphor systems with emission in the NIR-II region. Here, we report on Mn5+-doped Ba5(PO4)3Cl nanoparticles (BPCl:Mn5+ NPs, d < 50 nm) toward NIR-II temperature sensing. BPCl:Mn5+ NPs are made by a two-step (hydrothermal and anion exchange) method. XRD, SEM, and TEM results showed that the as-prepared BPCl:Mn5+ NPs show high crystallinity, uniform size, and sphere-like morphology. The nanoparticles exhibit a broad excitation band of 500–850 nm and a temperature-sensitive peak emission at 1175 nm in the NIR-II range. NIR-II temperature sensing by 1E emission intensity is demonstrated with good linear fitting (R2 = 0.9895), high sensitivity (2.30% at 373 K), and good repeatability (99.0%). Thus, our study provides a path to develop a new NIR-II thermometer based on tetrahedral Mn(V) coordination. [ABSTRACT FROM AUTHOR]