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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]

In this work, a facile hydrothermal method has been developed to synthesize a three-dimensional porous birnessite manganese dioxide hierarchical structure (pMHs) using thermally reduced graphene oxide paper as a sacrificing template. The morphology, microstructure, and thermal stability of the obtained samples were characterized by field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, N2 adsorption–desorption isotherms, and thermal gravimetric analysis. Furthermore, the electrochemical properties of the pMHs as an electrode material for supercapacitor were investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy in 1 M Na2SO4 electrolyte, and a specific capacitance of 194 F g−1 was achieved at a current density of 0.1 A g−1. The long-term stability implies that the synthesized pMHs is a good candidate as an electrode material for SCs. [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]

Ligating properties of a tripodal, potentially tetradentate aminetris(phenol) ligand, tris(2-hydroxy-3,5-di-tert-butylbenzyl)amine, H3L, containing [N,O,O,O] donor atoms toward the vanadium ions in +iiiand ivoxidation states have been studied. The structures of complexes 1[LVIII(CH3OH)]0, 2[LVIV(OCH3)]0and 3[LVIV(acac)]0were determined by X-ray diffraction methods as having five-coordinate V(iii), 1, five-coordinate non-oxo-vanadium(iv), 2, and six-coordinate non-oxo-vanadium(iv) 3, respectively. Compounds 1–3were also studied with electrochemical methods, variable-temperature (2–295 K) magnetic susceptibility measurements and X-band electron paramagnetic resonance (EPR) spectroscopy. The electrochemical results of 2and 3suggest metal-centered oxidation, i.e.the generation of a VV-phenolate species. EPR investigations indicate a (dxy)1ground state showing a considerable increase in the in-plane π-bonding, as is expected for a phenolate ligand. [ABSTRACT FROM AUTHOR]

The reaction of bis(ferrocenyl)methylsilane 1with two carbosilane dendritic cores containing terminal allyl units gives dendrimers functionalized with eight interacting ferrocenyl units. They show two reversible ferrocenyl waves in cyclic voltammetry (CV) and form derivatized Pt electrodes. Platinum electrodes modified with electrodeposited films of these two dendrimers exhibit electrocatalytic activity towards the reduction of oxygen and both oxidation and reduction of hydrogen peroxide. The molecular structure of 1has been determined by single-crystal X-ray diffraction studies. [ABSTRACT FROM AUTHOR]

The synthesis and full characterization using various spectroscopic techniques and single-crystal X-ray diffraction analysis of a family of three robust copper(ii)-centered complexes with organometallic donor–acceptor substituted unsymmetrical Schiff base ligands, namely, the binuclear derivatives Cu[Fc–C(O)CHC(CH3)N–X–NCH-(2-O,5-Br–C6H3)] (3: X = o-C6H4, 4: X = CH2CH2), and the corresponding ionic trinuclear counterpart of 4, [Cu{Fc–C(O)CHC(CH3)N–CH2CH2–NCH-(η6-2-O,5-Br–C6H3)RuCp*}][PF6] (5) (Fc = (η5-C5H5)Fe(η5-C5H4), Cp* = η5-C5Me5), have been explored. Single crystal X-ray diffraction analysis of complex 3indicates a bowed structure of the unsymmetrical Schiff base scaffold. The Cu2+ion is tetracoordinated in a square planar environment, with two nitrogen atoms and two oxygen atoms as donors. The EPR spectra of solid trinuclear complexes 5and 7(unsubstituted salicylidene ring and X = o-C6H4) at low temperature (68 K) consisted of fine-structure transitions (ΔMs = ±1) with zero-field splitting (ZFS) values of 0.0458 and 0.0415 cm−1, respectively, and a half-field signal (ΔMs = ±2) at ca.1600 G, suggesting the formation of dimeric species (S= 1). In those dimers, Cu–Cu distances of 3.97 and 4.14 Å, respectively, are computed from ZFS terms. The variable-temperature (2–300 K) magnetic susceptibilities of powdered samples of 5and 7have been measured, and an intermolecular antiferromagnetic interaction with exchange couplings of J= −1.05 and −0.65 cm−1, respectively, were found. The electrochemical behavior of both the neutral binuclear and ionic trinuclear compounds was investigated by cyclic voltammetry. Notably, the ability of the copper Schiff base core to transmit electronic effects between the two organometallic termini has been demonstrated by the observed anodic shift of the reversible voltammetric signal ascribed to the FeII/FeIIIcouple of the ferrocenyl donor fragment. [ABSTRACT FROM AUTHOR]

Four novel coordination polymers, {Na2[Co3(H2TTHA)2(H2O)12](H2O)2}·4(H2O) (1), {Na[Cu4(H2TTHA)(HTTHA)(H2O)8](H2O)3}·5(H2O) (2), [Cd3(TTHA)(H2O)4] (3) and [Ca5(HTTHA)2(H2O)8] (4), (H6TTHA = 1,3,5-triazine-2,4,6-triamine hexaacetic acid) have been synthesized by self-assembly of the flexible hexapodal acid H6TTHA and corresponding metal salts. The four complexes exhibit novel frameworks with different topologies due to diverse coordination modes and different conformations of the flexible H6TTHA. Complex 1shows a 3D network with (4,4,6)-connected topology constructed from parallel one-dimensional hybrid ribbons with nearly planar 24-membered rings, in which all Co(ii) atoms are located in one plane. Complex 2features a 3D (3,4,4,4,7)-connected network bridged by sodium ions from 2D layer structures which are formed through the interconnection of the tetranucleate units and the flexible ligands. Complex 3possesses hybrid layers constructed from zigzag Cd–O chains. These layers are further linked by the TTHA6−ligands with two configurations, leading to another 3D (3,3,8)-connected framework. The metal ions in complex 4are connected into wall-like infinite metal chains which are bridged by the carboxylate groups of ligands into a 3D (3,3)-connected hybrid framework. The framework is further furnished with the ligands forming hydrophobic channels with approximate sizes 3.5 Å × 9 Å based on the distances of the opposite atoms. The enantiometric pairs of ligands are formed in spite of no asymmetric carbon atom in complexes 1–3. Variable temperature magnetic studies down to 2 K reveal antiferromagnetic interactions in complexes 1and 2. Complexes 3and 4are both highly emissive at room temperature. And the luminescent intensities are largely enhanced once they are frozen to 10 K. [ABSTRACT FROM AUTHOR]

Trialkyl imido niobium and tantalum complexes [MR3(NtBu)] (M = Nb, R = Me 2, CH2CMe33, CH2CMe2Ph 4, CH2SiMe35; M = Ta, R = Me 6, CH2CMe2Ph 7, CH2SiMe38) have been prepared by treatment of solutions containing [MCl3(NtBu)py2] (M = Nb 1a, Ta 1b) with three equivalents of magnesium reagent. By an unexpected hydrolysis reaction of the tris-trimethylsilylmethyl imido tantalum compound 8a, a μ-oxo derivative [(Me3SiCH2O)(Me3SiCH2)3Ta(μ-O)Ta(CH2SiMe3)2(NtBu)] (8a) was formed and its structure was studied by X-ray diffraction methods. Reactions of trialkyl imido compounds with two equivalents of isocyanide 2,6-Me2C6H3NC result in the migration of two alkyl groups, leading to the formation of a series of alkyl imido bisiminoacyl derivatives [MR(NtBu){C(R)NAr}2] (Ar = 2,6-Me2C6H3; M = Nb, R = Me 9, CH2CMe310, CH2CMe2Ph 11, CH2SiMe312, CH2Ph 13; M = Ta, R = CH2CMe314, CH2CMe2Ph 15, CH2SiMe316). All compounds were studied by IR and NMR (1H, 13C and 15N) spectroscopy. [ABSTRACT FROM AUTHOR]

The high pressure structure of α-oxalic acid di-hydrate shows a prototypical behaviour of acid to base proton transfer reaction. The solid state transformation has been characterized by neutron and X-ray diffraction as well as by quantum chemical calculations with periodic boundary conditions. The two resonant configurations playing the most important role in the hydrogen bond mechanism, i.e.a neutral and a charge transfer configuration, are interchanged by modifying the pressure on the system. A different behaviour is predicted for the less common β form, despite an apparently similar packing motif. Implications for the characterization of hydrogen bonds in the solid state are discussed as well as the possibility of estimating internal energy variations from experimental measurements. [ABSTRACT FROM AUTHOR]

A series of flexible metal–organic frameworks (MOFs) have been successfully synthesized under hydrothermal condition using 1,3-adamantanediacetic acid (C14H20O4, H2ADA) as a flexible dicarboxylate building block, 4,4′-bipyridine and transition metal ions [Cd(ii), Zn(ii), and Mn(ii)] as metal centers in DMF and aqueous media. These MOFs formulated as [Cd(ADA)(4,4′-bipy)0.5]·(DMF) (Cd-ADA-1), [Mn(ADA)(4,4′-bipy)0.5]·(DMF) (Mn-ADA-1), Zn(ADA)(4,4′-bipy)0.5(Zn-ADA-1), and [Mn(HADA)2(4,4′-bipy)(H2O)2] (Mn-ADA-2) (ADA = 1,3-adamantanediacetate, 4,4′-bipy = 4,4′-bipyridine and DMF = N,N′-dimethyl formamide) display interesting 1D, 2D and 3D structural features depending on the solvent of synthesis. All these MOFs were structurally determined by single-crystal X-ray diffraction. The coordination modes of this ligand are discussed and in addition, thermal stability and hydrogen (H2) and carbon-dioxide (CO2) adsorption properties of Cd-ADA-1, Mn-ADA-1and Zn-ADA-1are also presented. Hydrogen sorption at 77 K and up to 1 atm is found to be 0.42, 0.72 and 1.36 wt% without saturation for Zn-ADA-1, Mn-ADA-1and Cd-ADA-1samples. [ABSTRACT FROM AUTHOR]

Two isomorphous 3D Mn(II) and Co(II) coordination polymers with a dicarboxylate inner salt and cyanate as coligands were synthesized and structurally characterized, and their magnetic properties have been studied. In the compounds, [M(L)(NCO)]n·nH2O (M = Mn, Co, L = 1-carboxymethylpyridinium-4-carboxylate), neighboring metal ions are linked by the 3-fold bridges of an end-on cyanate and two syn–syncarboxylate bridges to give an anionic chain of [M(µ-NCO)(µ–COO)2]n, and each chain is interlinked to four other chains by the cationic 1-methylpyridinium spacers to generate a 3D structure with the 42· 63· 8 net topology. They are the first compounds with mixed cyanate and carboxylate bridges. Magnetic studies reveal that the 3-fold mixed bridge propagates antiferromagnetic coupling in the Mn(II) compound but ferromagnetic coupling in the Co(II) compound. The rather complex magnetic behaviors of the Co(II) compound are analyzed taking into account the first-order spin-orbital coupling and the intrachain ferromagnetic interactions. [ABSTRACT FROM AUTHOR]

The ligand [(1,3-phenylene)bis(methylene)]bis(1-ethyl-imidazol-2-ylidene) (2) (abbreviated as EtCNHCCHCNHCwith CH = central aromatic ring, = CH2spacer) has been synthesised, and isolated, by deprotonation of [(1,3-phenylene)bis(methylene)]bis(1-ethyl-imidazolium) dichloride, Et(CHimid.CHCHimid.)Cl2(1) with LiN(SiMe3)2. This new, remarkably stable NHC dicarbene ligand is quantitatively protonated with HBr to form [(1,3-phenylene)bis(methylene)]bis(1-ethyl-imidazolium) dibromide Et(CHimid.CHCHimid.)Br2(3) and reprotonated slowly enough in MeOH to allow observation of the monoprotonated intermediate 4. Dicarbene 2reacts with S8to give the dithione compound [(1,3-phenylene)bis(methylene)]bis(1-ethyl-imidazol-2-thione) Et[(SC)CH(CS)] (6). Reaction of 2with [IrCl(CO)(PPh3)2] and [Ir(μ-Cl)(cod)]2yielded the mononuclear [Ir(CO)(PPh3)2Et(CHimid.CHCNHC)(PF6)](PF6) (8) and [IrCl(cod)Et(CHimid.CHCNHC)](PF6) (10) complexes, respectively, and the dinuclear complexes [{Ir(CO)(PPh3)2}2Et(μ-CNHCCHCNHC)](PF6)2(7) and [{IrCl(cod)}2Et(μ-CNHCCHCNHC)] (9), respectively, in which 2acts as a bridging, non-pincer type ligand. Only one other Ir(i) complex has been reported before containing a CNHCCHCNHCligand. The structures of 6and 9were determined by X-ray diffraction and depict different conformations of the (1,3-phenylene)bis(methylene) (or xylylene) moiety. The mononuclear Ir complex 9reacted smoothly with [Rh(μ-Cl)(cod)]2and Cs2CO3to generate a rare example of a heteronuclear NHC complex, [IrRhCl2(cod)2Et(μ-CNHCCHCNHC)] (11). [ABSTRACT FROM AUTHOR]

The combination of a [1111]metacyclophane blocked in 1,3-alternate conformation and bearing four imidazole units with MX2(M = Co, Cu, Zn and Hg; X = Cl or Br) complexes leads to the formation of a series of analogous neutral metallamacrotricycles. In all cases, the structure of the binuclear complexes has been studied by X-ray diffraction methods on single crystals. [ABSTRACT FROM AUTHOR]

Gold complexes of 4-isocyanobenzoic acid, [AuX(CNC6H4CO2H)] (X = CC–C6H4–C9H19, C6F5, C6F4OC6H13, C6F4C6F4Br) and [(μ-4,4′-C6F4C6F4){Au(CNC6H4CO2H)}2], have been isolated. These metallo-acids are luminescent. The single crystal X-ray diffraction study of [Au(C6F5)(CNC6H4CO2H)]∞confirms a rod-like structure of the molecule, with a linear coordination around the gold atom, which extends into a supramolecular entity supported by hydrogen bond, gold-gold, and fluorophilic (ForthoFmeta) interactions. The carboxylic acid group of the gold isocyanide complexes acts also as a hydrogen donor towards the hydrogen acceptor decyloxystilbazole, affording some hydrogen-bonded supramolecular liquid crystals. [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]

We demonstrated that the individual graphene oxide sheets can be readily reduced under a mild condition using l-ascorbic acid (l-AA). This simple approach should find practical applications in large scale production of water soluble graphene. [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]

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]

The high pressure structure of α-oxalic acid di-hydrate shows a prototypical behaviour of acid to base proton transfer reaction. The solid state transformation has been characterized by neutron and X-ray diffraction as well as by quantum chemical calculations with periodic boundary conditions. The two resonant configurations playing the most important role in the hydrogen bond mechanism, i.e.a neutral and a charge transfer configuration, are interchanged by modifying the pressure on the system. A different behaviour is predicted for the less common β form, despite an apparently similar packing motif. Implications for the characterization of hydrogen bonds in the solid state are discussed as well as the possibility of estimating internal energy variations from experimental measurements. [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]

[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]

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]

Hexadentate poly-Lewis acids (PLA) based on the bowl-shaped tribenzotriquinacene (TBTQ) have been synthesised. The introduction of three n-propyl groups into the benzhydrylic positions of the TBTQ backbone has significantly increased the solubility of the subsequently derived compounds. Semi-flexible PLAs containing boron and aluminium were obtained by hydrometallation of the corresponding 2,3,6,7,10,11-hexaalkynyl-TBTQ. Other rigid hexadentate PLAs were synthesised by stannylation of the corresponding alkyne units with Me3SnNMe2 followed by tin-element exchange reactions. The Lewis acidity of these PLAs was investigated in host–guest experiments with pyridine. Further experiments with bidentate bases showed correlations between their flexibility, their Lewis basicity and the complexation behaviour towards the synthesised PLAs. Addition of bis((dimethylphosphino)methyl)dimethylsilane (BisPhos) to solutions of the rigid alkynyl PLAs led to the formation of 3 : 1 adducts. Single crystal X-ray diffraction was used to further elucidate the host–guest connectivtiy. In addition, a sixfold pnictogen-bonding donor was synthesised by tin-antimony exchange. [ABSTRACT FROM AUTHOR]

The controlled preparation of oligopyrroles can be enabling for both chemistry and materials science. In this study, we present a straightforward one-pot synthesis that allows access to a series of α,α′-linked arene-bridged oligopyrrolic dialdehydes. The method relies on the Pd(0)-catalyzed tandem Suzuki cross-coupling of heterocyclic precursors. Access to the present diformyl oligopyrroles enables the construction of new macrocycles as confirmed by NMR spectroscopic and mass spectrometric studies, as well as single crystal X-ray diffraction analyses. [ABSTRACT FROM AUTHOR]

The present study is focused on the synthesis of DHPMs by using NiCoSe2 and NiCo2S4 as heterogeneous catalysts, and they are characterized by using XRD, SEM, TEM, BET and XPS. The NiCoSe2 and NiCo2S4 catalysts proved to be the most suitable catalytic system when compared to conventionally reported catalysts in terms of yield and reaction time. NiCoSe2 and NiCo2S4 are environment-friendly catalysts and can be recycled over 5 cycles with a negligible loss in the catalytic performance. Thus, the synthesized catalysts were successfully utilized in the synthesis of biologically active DHPMs, and all compounds were characterized using mass and NMR spectroscopic techniques. [ABSTRACT FROM AUTHOR]

The smectite group of clay minerals (smectites) consists of negatively charged clay layers and interlayer exchangeable cations. They are spontaneously delaminated in water to form single clay layers when the interlayer cations are small alkaline cations such as Na+ or Li+. This phenomenon known as osmotic swelling has fundamental importance in constructing novel clay-based nanomaterials. However, osmotic swelling of smectites has not been systematically investigated in organic solvents although this phenomenon should be useful for developing novel clay-organic nanocomposites. We report herein that montmorillonite, a typical smectite, with monovalent and divalent inorganic interlayer cations shows osmotic swelling accompanied by delamination of clay layers in water-acetonitrile and water-2-propanol mixed solvents, although inorganic interlayer cations have been believed to be inappropriate for delamination of smectites in organic solvents. The delamination is confirmed by a combination of macroscopic sample appearances, XRD patterns, and SEM images. Montmorillonite with interlayer Na+ or Li+ ions shows osmotic swelling in pure water and the mixed solvents but not in pure organic solvents. Montmorillonite with alkaline earth dications in the interlayer spaces is swollen in water-organic mixed solvents but not in either pure water or organic solvents alone. Partial delamination in several systems can be clarified from SEM images even though the sample appearances and XRD patterns do not give firm evidence. Such non-uniform swelling behavior of montmorillonite is related to the disordered stacking of the aluminosilicate layers with different morphologies in the clay powders as observed by SEM. [ABSTRACT FROM AUTHOR]

Near-infrared (NIR) emissive probes are becoming increasingly popular in biological sensing and imaging due to the advantages of non-invasiveness and deep tissue-penetrating ability. Herein, a series of complexes of trivalent lanthanide ions (Ln = Yb, Er, and Gd) with the commercially available azo dye chromophore 2R (Na2H2C2R) as ligand and featuring respectively H2O and dimethylsulfoxide (DMSO) as ancillary ligands have been prepared. Formulated as [Ln2(HC2R)2(H2O)10]·8H2O (1-3, Ln = Yb, Er, Gd) and [Ln2(HC2R)2(DMSO)10]·2DMSO (4-6, Ln = Yb, Er, Gd), their structures have been determined by singlecrystal X-ray diffraction studies. Photophysical property studies revealed NIR emissions of the DMSO complexes characteristic of Yb(III) and Er(III), effectively sensitized by the dye ligand arising mainly from the π-π* transition of the chromophore. The long-wavelength excitation of the complexes, covering the whole visible-light range and extending into the NIR region, portends the potential applications of such complexes for flexible bioimaging and sensing. [ABSTRACT FROM AUTHOR]

A copper oxide (CuO)-based nanocomposite with different concentrations of polyacrylonitrile (PAN) and curcumin was synthesized for antibacterial applications. An electrospinning method was utilized to synthesize PAN/CuO and PAN/CuO/curcumin nanofibers, which were incorporated into a face mask to confer it with antimicrobial activity. The analysis of the XRD pattern of CuO confirmed the crystalline monoclinic phase. The FTIR peaks at 3439 cm−1, 1369 cm−1, and 3720 cm−1 were attributed to the O–H stretching band of water, stretching vibrations due to C＝O, and C–H stretching vibrations of the CH2 group of bonding from acrylonitrile, respectively, confirming the formation of PAN nanofibers. The peak at 668 cm−1 assigned to Cu–O stretching indicated the presence of CuO. A 7 mm-diameter PAN/CuO nanofiber zone could inhibit about a 15 mm zone of E. coli, whereas just a 3 mm-diameter PAN/CuO/curcumin nanofiber zone could inhibit about a 19 mm zone of E. coli. This indicated that the PAN/CuO/curcumin nanofibers have excellent antibacterial properties compared to the PAN/CuO nanofibers against Escherichia coli (E. coli). In contact angle, the PAN nanofibers were hydrophilic, whereas the PAN/CuO and PAN/CuO/curcumin nanofibers showed a hydrophobic nature. Hence, the present study indicates that PAN/CuO/curcumin nanofiber–based materials can efficiently protect against bacteria, and this would be an outstanding improvement for low-cost surgical face masks. [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]

Reactions between 1,2-di(tetrazol-2-yl)ethane (ebtz), 1,6-di(tetrazol-2-yl)hexane (hbtz) or 1,1′-di(tetrazol-1-yl)methane (1ditz) and Fe(BF4)2 in the presence of adiponitrile (ADN), glutaronitrile (GLN) or suberonitrile (SUN) resulted in the formation of coordination polymers [Fe(μ-ebtz)2(μ-ADN)](BF4)2 (1), [Fe(μ-hbtz)2(μ-ADN)](BF4)2 (2), [Fe(μ-1ditz)2(GLN)2](BF4)2·GLN (3) and [Fe(μ-1ditz)2(μ-SUN)](BF4)2·SUN (4). It was established that the application of dinitriles allows an increase in the dimensionality of the ebtz and hbtz based systems while maintaining the structure of the polymeric units characteristic of previously studied mononitrile based analogues. In 3 and 4, regardless of the type of dinitrile coligand, the motif of 2D polymeric layers constituted by 1ditz molecules remains preserved. However, the dimensionality of 1ditz based networks is governed by the coordination modes of dinitriles. 3, based on a shorter molecule of glutaronitrile, crystallizes as a two-dimensional (2D) coordination polymer. In this compound, dinitriles coordinate monodentately or play the role of guest molecules. The substitution of glutaronitrile with suberonitrile enables the bridging of neighboring polymeric layers, resulting in a 3D network. The intentional selection of bis(tetrazoles) and dinitriles as building blocks has led, as expected, to obtaining systems with the structure of the first coordination sphere consisting of four tetrazole rings and two axially coordinated nitrile molecules. It created the conditions required for the occurrence of thermally induced spin crossover. Magnetic measurements and single crystal X-ray diffraction studies were used for the characterization of the spin crossover properties of 1–4. [ABSTRACT FROM AUTHOR]

One of the important procedures to enhance the activity of semiconductors as a catalyst is the fabrication of Ag-based semiconductors with a large bandgap energy. Here, a novel Ag/β-Ag2WO4/V3O4/g-C3N4 heterojunction photocatalyst was synthesized by a solvothermal method. The heterojunction structure was characterized by FT-IR spectroscopy, DRS, FE-SEM, XRD, PL, and EDS techniques. The photo-ability of V3O4, V3O4/g-C3N4, and Ag/β-Ag2WO4/V3O4/g-C3N4 toward the actuation of C(OH)–H bond was investigated using a visible lamp. The prepared photocatalyst illustrated impressive activity compared to pure V3O4 and V3O4/g-C3N4, which was 67% under aerobic environments due to the considerable separation of the photogenerated charge pairs and enhanced active sites after the incorporation of nanoparticles. Accordingly, this catalyst should be introduced as a qualified photocatalyst, because of its activity, selectivity, and stability. [ABSTRACT FROM AUTHOR]

FeNbO4 sonocatalysts were successfully synthesized by a simple hydrothermal route at pH values of 3, 5, 7, 9 and 11. The catalysts were characterized by XRD, XPS, TEM, SEM, N2 adsorption and DRS to analyse the effect of pH parameters on the physicochemical properties of the materials during hydrothermal synthesis. The sonocatalytic activity of FeNbO4 microspheres was evaluated by using acid orange 7 (AO7) as the simulated contaminant. The experimental results showed that the best sonocatalytic degradation ratio (97.45%) of organic dyes could be obtained under the conditions of an initial AO7 concentration of 10 mg L−1, an ultrasonic power of 200 W, a catalyst dosage of 1.0 g L−1, and a pH of 3. Moreover, the sonocatalysts demonstrated consistent durability and stability across multiple test cycles. After active species capture experiments and calculation of the energy band, a possible mechanism was proposed based on the special Fenton-like mechanism and the dissociation of H2O2. This research shows that FeNbO4 microspheres can be used as sonocatalysts for the purification of organic wastewater, which has a promising application prospect. [ABSTRACT FROM AUTHOR]

Reaction between TeO2 and I2 in HCl afforded a series of supramolecular hybrids Cat2{[TeCl6](I2)} (1-5) where diiodine fragments are linked to [TeCl6]2- octahedra via halogen bonds (XB). The compounds were characterized using X-ray diffraction, revealing one- and two-dimensional anionic motifs built via I·Cl supramolecular interactions. Features of non-covalent interactions were studied via quantum chemistry methods and Raman spectroscopy. Compounds 1-3 showed relatively narrow band gaps of 1.50-1.59 eV. [ABSTRACT FROM AUTHOR]

Perovskite materials are emerging as the most promising and efficient low-cost energy materials for various applications. The construction of heterojunctions has become a field of interest because of their high potential to give off a large amount of energy. Herein, a Z-scheme heterojunction was made between two perovskites (CoTiO3 and CaTiO3) in order to make a cheap material that is good at photocatalysis. Various methods were used to characterize the resulting CoTiO3/CaTiO3 (CCO 75: 25) composite, including XRD, Raman, XPS, HRSEM, HRTEM, BET, and UV-vis. The increased photocatalytic activity of the CoTiO3/CaTiO3 (CCO) composite is attributed to the accelerated charge transfer from O2- to Ti4+ and from Co2+ to Ti4+ ions, revealing the close interfacial contact between CoTiO3 and CaTiO3, and spatial charge transfer within the CoTiO3/CaTiO3 heterojunction. A direct Z-scheme mechanism was developed, and charge transfer properties were verified by the scavenger test and ESR, PL, and EIS analyses. The enhanced degradation rate of k = 0.0373 min-1 is achieved for the CCO 75: 25 composite. Meanwhile, the CCO 75: 25 composite established high photocatalytic stability when recycled for CBZ degradation. This research offers mechanistic and practical views on designing simple and cost-effective materials for pollutant removal. [ABSTRACT FROM AUTHOR]

We have used high-pressure synthesis to synthesize samples of Ca2-xMnxTi2O6 double perovskite, where x varies between 0.2 and 1. The synthesized materials were structurally characterized with powder X-ray diffraction (XRD). Rietveld refinement of the XRD patterns was used to study the change from CaTiO3 (x = 0) to the composition CaMnTi2O6 (x = 1) where half of the Ca(II) ions are replaced by smaller Mn(II) ions. We analyzed the peak shapes in the XRD patterns, as well as lattice parameters, and it appears that smooth symmetry change from the centrosymmetric space group Pbnm to the non-centrosymmetric space group P42mc occurs between x = 0.3 and x = 0.5. We also confirmed the centrosymmetric to noncentrosymmetric transition by characterizing the dielectric properties of the materials with ferroelectric measurements. [ABSTRACT FROM AUTHOR]

The application of Mg[Ph4Pn] and Li·K[Ph4Pn] in transmetalation reactions to a range of Rh(I) precursors led to the formation of "half-baguette" anti-[Rh I(L) n ]2[μ:η5:η5Ph4Pn] (L = 1,5-cyclooctadiene, norbornadiene, ethylene; n = 1, 2) and syn-[Rh I(CO)2]2[μ:η5:η5Ph4Pn] complexes as well as the related iridium complex anti-[Ir I(COD)]2[μ:η5:η5Ph4Pn]. With CO exclusive syn metalation was obtained even when using mono-nuclear Rh(I) precursors, indicating an electronic preference for syn metalation. DFT analysis showed this to be the result of π overlap between the adjacent M(CO)2 units which overcompensates for dz2 repulsion of the metals, an effect which can be overridden by steric clash of the auxiliary ligands to yield anti-configuration as seen in the larger olefin complexes. syn-[Rh I(CO)2]2[μ:η5:η5Ph4Pn] is a rare example of a twinned organometallic where the two metals are held flexibly in close proximity, but the two d8 Rh(I) centres did not show signs of M–M bonding interactions or exhibit Lewis basic behaviour as in some related mono-nuclear Cp complexes due to the acceptor properties of the ligands. The ligand substitution chemistry of syn-[Rh I(CO)2]2[μ:η5:η5Ph4Pn] was investigated with a series of electronically and sterically diverse donor ligands (P(OPh)3, P(OMe)3, PPh3, PMe3, dppe) yielding new mono- and bis-substituted complexes, with E-syn-[Rh I(CO)(P{OR})3]2[μ:η5:η5Ph4Pn] (R = Me, Ph) characterised by XRD. [ABSTRACT FROM AUTHOR]

Hexagonal Ag3YCl6 was found to transform into a new phase by applying pressure above ∼1.5 GPa via a diamond anvil cell. In situ XRD analysis revealed that the phase is monoclinic Ag3YCl6. The bulk modulus of the hexagonal and monoclinic phases was 37 GPa and 49 GPa, respectively. Computational investigations also supported this phase transition and bulk modulus. After releasing pressure from 2 GPa, the diffraction peaks of hexagonal Ag3YCl6 were detected, indicating the reversibility of this phase transformation. [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]

This paper reports two closely related heteropentanuclear manganese complexes, namely, {Na2Mn3(opch)3(μ4-O)(μ2-N3) (μ2-AcO)(μ2-MeO)}·6CH3OH·0.5H2O (1) and {Na2Mn3(opch)3(μ4-O)(μ2-N3)2(μ2-AcO)}·2.5CH3OH·2H2O (2), where H2opch is (E)-N′-(2-hydroxy-3-methoxybenzylidene)pyrazine-2-carbohydrazide. Single-crystal X-ray diffraction analysis reveals that the trigonal bipyramidal skeletons in both complexes are comparable, where a perfect triangular Mn3 motif occupies the equatorial plane. Magnetic investigations suggest that overall antiferromagnetic coupling is present within the triangles of 1 and 2. However, their dynamic magnetic properties are drastically distinct. Indeed, complexes 1 and 2 show two kinds of dual slow magnetic relaxation processes that correspond to anisotropy barriers (Δ) of 9.2 cm−1 (11.4 cm−1 for 2) and 12.8 cm−1 (30.0 cm−1 for 2) for the low- and high-frequency domains, respectively. More importantly, a further comparative study of the structure and magnetism indicates that the coordination sphere of these two model complexes with the homologous hydrazone-based coordination sites undergoes an alteration from methoxide-O to azide-N upon a subtle change of the auxiliary anion accompanied by modulating octahedron geometries, leading to a further influence on different relaxation dynamics. [ABSTRACT FROM AUTHOR]

Monitoring blood glucose levels in diabetic patients is vital, pressing the need for sensitive and affordable glucose sensors. Electrochemical sensing, gaining prominence due to drawbacks of enzymatic and optical methods, has been a major research focus. Here, we explore mesoporous Santa Barbara Amorphous-15 (SBA-15) supported bimetallic copper nickel oxide for electrochemical glucose estimation. Rigorous characterisation via XRD, BET, and XPS confirmed metal oxide integration into the SBA-15, and the retention of the framework was validated by XRD, SEM, and TEM analyses. Cyclic voltammetry (CV) studies revealed sensor versatility across the 10 to 900 μM range with a commendable lower detection limit of 1.19 μM. Furthermore, the optimized 30Cu–20Ni/SBA-15/Triton/GCE sensor exhibited exceptional stability and negligible interference from common interfering species such as sucrose, fructose, uric acid, and ascorbic acid. In addition, the practical utility was tested by employing artificial blood serum and urine samples. The sensor's outstanding attributes, including cost-effectiveness and clinical suitability, present promising advancements in electrochemical glucose detection, opening new avenues in electrochemical sensing. [ABSTRACT FROM AUTHOR]

This manuscript is focused on the synthesis of biologically derived carbon quantum dots (CQDs) via hydrothermal methods using Aloevera leaves (Aloe barbadensis miller). The proposed biochemical route, utilizing Aloevera gel, has garnered attention due to its cost-effectiveness, eco-friendly nature, and ability to produce highly pure, stable, and fluorescent biologically derived self-assembled nanoparticles measuring approximately 5–6 nm in size. The primary objective was to harness plant sources and establish a sustainable and renewable platform for synthesizing valuable nanostructures, encouraging researchers to shift their focus from unhealthy chemicals to natural resources for healthier and non-polluting investigations. The synthesized CQDs exhibited remarkable colloidal properties, excellent fluorescence, and photostability under UV light. Characterization techniques such as powder XRD, UV-Vis spectroscopy, photoluminescence, FT-IR, AFM, and TEM were employed to analyse the prepared CQDs. Furthermore, the prepared CQDs displayed significant electrochemical behaviour in the presence of tyrosinase enzyme to detect Bisphenol-A, which functions as an endocrine disruptor (ED). These nanomaterials were also utilized for electrochemical biosensing applications. Additionally, the fabricated CQDs exhibited unique structural and morphological characteristics, along with efficient electrochemical properties, which are thoroughly discussed in the manuscript. [ABSTRACT FROM AUTHOR]

The crystalline quality of perovskite films is a key factor that affects the performance of perovskite photovoltaic devices. Polyoxometalates can better match the energy levels of each layer in the devices through their own suitable energy level and band gap, and the good light absorption of POMs can also increase the mobility of photogenerated carriers in the devices. Moreover, POMs with Keggin-type structures can also improve the crystalline quality of perovskite films by eliminating defect sites, which can lead to better crystallization of perovskites with larger grains. In this study, we optimized the crystalline quality of a perovskite layer using the SiW9Co3@rGO composite prepared using POMs and graphene derivatives. XRD and SEM tests show that the crystallization degree of the perovskite layer was improved, the average grain size of which can reach up to 1222.92 nm, which is nearly four times higher than that of a blank perovskite. The photoresponse current of a SiW9Co3@rGO-doped photodetector can reach to 43.94 μA, which is about 226% higher than that of an undoped device. At the same time, the addition of the composite can improve the stability of photodetectors because of the special network structure of graphene. Photodetectors doped with SiW9Co3@rGO can still maintain more than 90% of their high performance for a month. This study proves that POM-based composites have good application prospects in the field of photovoltaic devices. [ABSTRACT FROM AUTHOR]

Addressing the delicate balance between the energy and sensitivity of energetic materials has been a prominent research focus. Here, 7,8-dinitropyrazolo[1,5-a][1,3,5]triazine-2,4-diamine (ICM-104) is assembled with oxidizer ions through coulombic interactions, achieving an increase in energy while maintaining relatively low sensitivity. X-ray diffraction results indicated that the two energetic salts have a layered structure different from that of ICM-104, and have high densities of 1.89 and 1.95 g cm−3, which are higher than most other energetic salts. Both have excellent thermal detonation velocity (8813 and 8857 m s−1) and detonation pressure (33.2 and 35.7 GPa), higher than 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) (D: 8795 m s−1, P: 34.9 GPa). Moreover, compound 1 exhibits low mechanical sensitivities (FS > 360 N, IS > 40 J), which has great potential as an insensitive energetic material. In addition, two energetic salts have favorable laser-ignited combustion and propulsion performances, which provide new strategies for the formulation design of solid propellants. [ABSTRACT FROM AUTHOR]

The influence of the metal ratio on the geometric characteristics and crystal structures of heterometallic clusters with {Re6−xMoxQ8} cores was studied. For this purpose, nine new molecular cluster complexes of the type [Re6−xMoxS8L6] (x = 2, 3 or non-integer value between 2 and 3; L = pyridine, 4-ethylpyridine or 4-tert-butylpyridine) were synthesized. The compounds were obtained by one-step replacement of the cyanide apical ligands of [Re6−xMoxS8(CN)6]5−/4− cluster complexes with the corresponding organic compounds under solvothermal conditions. The crystal structures of all the obtained compounds were investigated by single-crystal X-ray diffraction analysis. Analysis of the crystal structures showed that clusters with the same apical ligands and different x values have similar geometries and form isostructural packings, demonstrating the formation of solid solutions. [ABSTRACT FROM AUTHOR]

Polyiodides present high bonding flexibility already at ambient conditions, and undergo significant pressure-induced structural deformations. Resonant Raman spectroscopy has been widely used to study I–I bonds in various polyiodides, but it carries a risk of photodecomposition due to the high visible-light absorption of iodine. In this study, tetraethylammonium (bis)diiodine triiodide (TEAI) has been investigated by resonant Raman spectroscopy up to 12.02(3) GPa. The effect of pressure on the intensities and positions of Raman bands has been evaluated and correlated with the interatomic I–I distances derived from high-pressure X-ray diffraction experiments. Pressure was shown to effectively stabilize TEAI against laser-induced photodecomposition, even after a long course of irradiation with the resonant laser light. Examination of a freshly exposed crystal surface revealed that TEAI superficially passivates with the layer of lower polyiodides, which prevents further iodine loss, and shows distinct pressure-induced behaviour. [ABSTRACT FROM AUTHOR]

Here, a cyclometalated Pt(II) clamshell dimer (complex 2) has been synthesized with the primary ligand of dibenzo(f,h)quinoxaline and an ancillary ligand of N,N′-diphenylformamidine. In addition, a mononuclear Pt(II) complex 1a and a binuclear Pt(II) complex 1b were also prepared. Complex 1a was coordinated by one cyclometalated ligand of dibenzo(f,h)quinoxaline, one chloride ion, and one N,N′-diphenylformamidine. Complex 1b was coordinated by one cyclometalated ligand of dibenzo(f,h)quinoxaline, two chloride ions, and two N,N′-diphenylformamidines. All of these three complexes were characterized by nuclear magnetic resonance (NMR) spectroscopy, high-resolution mass spectrometry (HRMS), elemental analyses, and single-crystal X-ray diffraction (XRD). The Pt–Pt distance in complex 2 was 2.8439(2) Å. It also exhibited a near-infrared (near-IR) emission at 887 nm in the pure solid state. On the other hand, complexes 1a and 1b exhibited triplet emission at 589 and 660 nm, respectively, in the pure solid state. Furthermore, in 2 wt% poly(Me methacrylate) (PMMA) films, complex 1a showed a triplet emission at 548 nm (with Φ = 84% and τ = 5.53 μs) and complex 1b showed an emission at 627 nm (with Φ = 79% and τ = 4.07 μs). Due to its great photophysical properties, complex 1b was deposited onto quartz plates for the detection of organic solvent vapors and it showed unique emission quenching for the vapor of tetrahydrofuran. [ABSTRACT FROM AUTHOR]

para-Aminobenzoic acid (p-ABA) is a pharmaceutical compound with a challenging polymorph nucleation behavior. It has 4 polymorphs and multiple solvates. Among these forms, the α and the β form are subjects of interest for research in many studies. The α form nucleates predominantly in many solvents. The β form is known to nucleate in only 2 solvents. The reasoning for this was that the solvents, having a strong interaction with the COOH group, inhibit the dimerization of the COOH group leading to the nucleation of the β form. Following this reasoning, in this work, DMSO and DMF, which have strong interaction with the COOH group, were tested as solvents for anti-solvent crystallization experiments. Water was used as anti-solvent. The goal was to investigate the resultant polymorph nucleation under such specific solvent–solute interaction. Results showed that with DMSO as solvent at higher anti-solvent volume fraction the α form nucleated predominantly. At lower volume fractions there was no nucleation normally but addition of some seeds quickly led to β form nucleation. With DMF, a special result was seen where a new solvate between p-ABA and DMF was discovered. Single crystal XRD results confirmed that the formation of the solvate was a result of hydrogen bonding between the solute and the solvent. Overall, the results do confirm that solvents having strong interaction with the COOH group can lead to nucleation of forms other than the persistent form. [ABSTRACT FROM AUTHOR]

In the present investigation, glycerol and dimethyl carbonate were transesterified using a Li/Mg/K modified zeolite beta catalyst to synthesize glycerol carbonate. The various prepared zeolite catalysts were characterized using XRD, FE-SEM, EDS, HR-TEM, XPS, and DLS techniques. Many tests were conducted to optimize the reaction conditions to obtain the highest yield of glycerol carbonate by changing the catalyst concentration (5–20 wt%), glycerol-to-dimethyl carbonate mole ratio (1 : 2–1 : 6), and reaction temperature (65–105 °C). A maximum of 81.48% glycerol carbonate was obtained under optimized reaction conditions (a glycerol : dimethyl carbonate mole ratio of 1 : 5, a Li20β dosage of 10 wt% w.r.t. GLY, a temperature of 95 °C, and a time of 5 h). The experimental data followed second-order reaction kinetics with an activation energy of 34.60 kJ mol−1. [ABSTRACT FROM AUTHOR]

Na3Sc2−xRx(PO4)3 (R = Eu, Tb, Dy; 0 ≤ x ≤ 0.2) phosphors were synthesized by a high-temperature solid-state reaction. Sc : R ratios for the NSP:xR samples were determined by ICP-MS, EDX-SEM and TEM-EDX measurements. An X-ray diffraction study revealed that solid solutions with a NASICON-type structure were formed at 0 ≤ x ≤ 0.1. The luminescence properties of Na3Sc2(PO4)3 and Na3Sc2−xRx(PO4)3 (R = Eu, Tb, Dy) were studied in the range of 80–500 K. The highest R3+ luminescence intensity in Na3Sc2−xRx(PO4)3 (R = Eu, Tb, Dy) depending on R was found for x = 0.05 in the case of Dy and x = 0.1 in the case of Eu and Tb. The temperature behaviour of the R3+ emission intensity of Na3Sc2−xRx(PO4)3 (R = Eu, Tb, Dy) depends on R that replaces Sc. The decrease of the Eu3+ emission intensity depending on the transition energy by ∼26% and 18% at ∼420 K compared to TR allowed us to consider NSP:0.1Eu3+ as a suitable phosphor for pc-LEDs. The temperature dependence of the Dy3+ emission for NSP:0.05Dy3+ demonstrates a strong thermal quenching. Different temperature dependences of the Tb3+ emission intensity of NSP:0.1Tb3+ were found for two excitation bands at λex = 220 and 378 nm representing f–d and f–f intracentre transitions. No thermal quenching for f–f transitions takes place while the emission intensity for f–d transitions increases with a temperature rise from 80 to 500 K. The dielectric measurements for Na3Sc2(PO4)3 and Na3Sc1.9Eu0.1(PO4)3 were provided on ceramic pellets sintered under vacuum using a spark plasma sintering technique. Different dependences of conductivity were found for two samples. The calculated conductivity for Na3Sc1.9Eu0.1(PO4)3 with an R3¯c structure (σbulk = 6.4 × 10−5 S cm−1 at 300 K, 1.14 × 10−3 S cm−1 at 360 K and 5.0 × 10−2 S cm−1 at 500 K) is higher than that for pure α-Na3Sc2(PO4)3 but lower than that for β- and γ-Na3Sc2(PO4)3. [ABSTRACT FROM AUTHOR]

The polymeric linear chain [AuTl(C6Cl5)2]n reacts with three terpyridine-type ligands substituted with thiophene groups containing N-donor centres in different relative positions (L1, L2 and L3), leading to the Au(I)/Tl(I) complexes [AuTl(C6Cl5)2(L1)]n (1), [{AuTl(C6Cl5)2}2(L2)]n (2) and [AuTl(C6Cl5)2(L3)]n (3). X-Ray diffraction studies reveal that L1 acts as a chelate, while L2 and L3 act as bridging ligands, resulting in different coordination indexes for the thallium(I) centre. These structural differences strongly influence their optical properties, and while compounds 2 and 3 emit near the limit of the visible range, complex 1 emits in the infrared region. DFT calculations have also been carried out in order to determine the origin of the electronic transitions responsible for their optical properties. [ABSTRACT FROM AUTHOR]

Controllable fluorination of silicate materials has been hardly accomplished mainly due to the high reactivity of fluorinating substances. In this study, the introduction of fluorinating substances into the interlayer space of magadiite in neutral form was attempted to induce an in situ fluorination reaction preferably on the interlayer surface of layered silicates. Two types of fluorinating substances, inorganic ammonium fluoride salts and organic 4-tert-butyl-2,6-dimethylphenylsulfur trifluoride (Floulead), were successfully intercalated into the interlayer space of magadiite without any significant deterioration of the framework. Subsequent in situ fluorination reactions led to the preferred fluorination of the layered silanol groups that was envisioned successfully in the XRD pattern, FT-IR spectrum, TG/DTA curve, and cation exchange capacity. This study demonstrates that the silicate materials could be fluorinated selectively through intercalation and subsequent in situ localized reactions of various fluorinating substances. [ABSTRACT FROM AUTHOR]

We present a new synthetic strategy for obtaining mixed-valence triiron complexes where the metal centers are bridged by a novel, highly functionalized hydrocarbyl ligand. The alkynyl–vinyliminium complexes [Fe2Cp2(CO)(μ-CO){μ-η1:η3-C(X–C≡CH)CHCNMe2}]CF3SO3 (X = 4-C6H4, [2a1]CF3SO3; X = (CH2)3, [2a2]CF3SO3) were synthesized in almost quantitative yields from the aminocarbyne precursor [Fe2Cp2(CO)2(μ-CO){μ-CNMe2}]CF3SO3, [1a]CF3SO3, and the di-alkynes HC≡C–X–C≡CH. Then, the ferracycle [Fe(Cp)(CO){C(NMe2)CH＝C(4-C6H4C≡CH)C(O)}], 4a1, was produced in 47% yield from the cleavage of [2a1]CF3SO3 promoted by pyrrolidine. Subsequent reactions of the acetonitrile adducts [Fe2Cp2(CO)(μ-CO)(NCMe){μ-CNMe(R)}]CF3SO3 (R = Me, [1aACN]CF3SO3; R = Xyl, [1bACN]CF3SO3) ([FeIFeI]) with 4a1 ([FeII]) at room temperature resulted in the formation of [FeIFeIFeII] complexes [Fe2Cp2(CO)(μ-CO){μ-η1:η3-C(X–C＝CHC(NMe2)＝FeCp(CO)C＝O)CHCNMe(R)}]CF3SO3 (R = Me, [5a1]CF3SO3; R = Xyl, [5b1]CF3SO3) in yields ranging from 56% to 64%. The new products were characterized by IR and multinuclear NMR spectroscopy, and the structures of [2a2]CF3SO3 and 4a1 were confirmed by single crystal X-ray diffraction. Cyclic voltammetry and spectroelectrochemical studies on [5a1]+ have revealed that reduction and oxidation events occur almost independently at the [FeIFeI] and [FeII] units, respectively. This observation underscores a minimal electronic interaction between the two fragments within the triiron complex. Accordingly, DFT studies pointed out that the HOMO and LUMO orbitals are predominantly localized in the two distinct compartments of [5a1]+. [ABSTRACT FROM AUTHOR]

Two carbonyl and o-NH2–NO2-containing energetic materials and their analogues were effectively designed, synthesized and fully characterized with multinuclear NMR, IR and elemental analyses. Their structures were also further confirmed via X-ray diffraction. Among them, compound 7 exhibits good potential for application as a secondary explosive with extremely high density (2.04 g cm−3), good sensitivity (IS > 40 J, FS > 360 N), and excellent calculated detonation performance (Dv = 8943 m s−1, P = 35.0 GPa). Furthermore, a detailed comparative study based on X-ray diffraction, Hirshfeld surfaces and 2D fingerprint plots among compounds 4, 7 and 9 has demonstrated that the density and detonation performance could be effectively improved via introducing a carbonyl group into fused-ring compounds. More importantly, the sensitivity of the resulting energetic materials did not deteriorate. Obviously, this strategy via introducing carbonyl, o-NH2–NO2 and nitroamino groups into fused-ring energetic compounds will help in the design of next-generation high-energy and insensitive fused-ring energetic materials. [ABSTRACT FROM AUTHOR]

There is an urgent need for new CO2 adsorbents to overcome the rapidly increasing CO2 pollution. New CuO@UiO-67 composites were prepared by encapsulating CuO nanoparticles (NPs) in the shallow pore channels of UiO-67 through postsynthetic exchange (PSE) to form a core–shell structure. The composites were characterized via TEM, XRD, and BET analyses, and single component adsorption isotherm measurements of CO2, CH4 and N2 were performed at different temperatures. The selectivities of CO2/CH4 and CO2/N2 and the isosteric heats of CO2 adsorption were estimated based on the ideal adsorption solution theory (IAST) and the Clausius–Clapeyron equation, respectively. The highest CO2 uptake of CuO@UiO-67 was achieved at 273 K and 100 kPa with 61.9 cc g−1, which was twice that of parent UiO-67. The significant increase in CO2 uptake was not only due to the introduction of CuO NPs in the pore channel of CuO@UiO-67, but also due to the new open nitrogen sites due to ligand substitution. The adsorption selectivities of CO2/CH4 and CO2/N2 at 298 K and 100 kPa were 9.2 and 54.3, respectively. Furthermore, CuO@UiO-67 could efficiently separate the CO2/N2 mixture under a dynamic flow condition. These excellent properties suggest that the CuO@UiO-67 composite is a promising and efficient CO2 adsorbent material. This study lays a solid foundation for metal oxide-modified MOFs and is a great contribution to the preparation of new adsorbents. [ABSTRACT FROM AUTHOR]

This study describes the discovery of a unique ionic cocrystal of the active pharmaceutical ingredient (API) ponatinib hydrochloride (pon·HCl), and characterization using single-crystal X-ray diffraction (SCXRD) and solid-state NMR (SSNMR) spectroscopy. Pon·HCl is a multicomponent crystal that features an unusual stoichiometry, with an asymmetric unit containing both monocations and dications of the ponatinib molecule, three water molecules, and three chloride ions. Structural features include (i) a charged imidazopyridazine moiety that forms a hydrogen bond between the ponatinib monocations and dications and (ii) a chloride ion that does not feature hydrogen bonds involving any organic moiety, instead being situated in a "square" arrangement with three water molecules. Multinuclear SSNMR, featuring high and ultra-high fields up to 35.2 T, provides the groundwork for structural interpretation of complex multicomponent crystals in the absence of diffraction data. A 13C CP/MAS spectrum confirms the presence of two crystallographically distinct ponatinib molecules, whereas 1D 1H and 2D 1H–1H DQ–SQ spectra identify and assign the unusually deshielded imidazopyridazine proton. 1D 35Cl spectra obtained at multiple fields confirm the presence of three distinct chloride ions, with density functional theory calculations providing key relationships between the SSNMR spectra and H⋯Cl− hydrogen bonding arrangements. A 2D 35Cl → 1H D-RINEPT spectrum confirms the spatial proximities between the chloride ions, water molecules, and amine moieties. This all suggests future application of multinuclear SSNMR at high and ultra-high fields to the study of complex API solid forms for which SCXRD data are unavailable, with potential application to heterogeneous mixtures or amorphous solid dispersions. [ABSTRACT FROM AUTHOR]

A novel and efficient "on water" mediated one-pot ZnMnO3@Ni(OH)2 catalyzed straight-forward synthesis of 3-hydroxy-3-(3-methyl-5-oxo-2-thioxoimidazolidin-4-yl)oxindole via a thiazolidinedione–isatin conjugate has been explored. Concurrently, temperature-regulated dehydrated adducts of 3-hydroxy-3-(3-methyl-5-oxo-2-thioxoimidazolidin-4-yl)oxindole were also demonstrated. The use of a recyclable ZnMnO3@Ni(OH)2 nano-catalyst in the aqueous medium makes the protocol sustainable and green. The synthesis of ZnMnO3@Ni(OH)2 nanopowder has been meticulously characterized using powdered XRD, HRTEM, EDX and BET analyses. Moreover, the choice of readily available and readily made starting materials under mild and operationally simple reaction conditions is the major advantage of this strategy. The catalyst exhibits high water compatibility and demonstrates the ability to be recycled and reused for a minimum of eight cycles. Through a standard leaching experiment, it was confirmed that the reaction proceeded heterogeneously with this recyclable catalyst. [ABSTRACT FROM AUTHOR]

A series of 6-oxo-3-(1,2,4,5-substituted-1H-imidazol-3-ium-3-yl)-3,6-dihydro-1,2,4,5-tetrazin-3-ides (3a–3z, 3aa–3ak) was synthesized with medium to good yield by the reaction of 3,6-dichloro-1,2,4,5-tetrazine with a variety of substituted imidazoles in the presence of trace water in solvents. The quinoidal-like structure of these compounds was demonstrated via spectroscopic methods, X-ray diffraction techniques, and computational chemistry. Additionally, water–18O was used to prove that the oxygen in tetrazinone comes from the water in solvents via high-resolution mass spectrometry (HRMS). Moreover, a possible mechanism of aromatic nucleophilic substitution is proposed. [ABSTRACT FROM AUTHOR]

This study is focused on determining the type and quantity of REE impurities responsible for converting the structure of NdSc3(BO3)4 into an R32 polymorph. According to the single crystal X-ray diffraction of RxNdyScz(BO3)4 (R = Sm–Lu, x + y + z = 4) the samples probably contain several polymorphic modifications. However, the predominant structure has been defined as R32 for R = Eu, Er, Tm, and Yb and P3221 for R = Sm, Gd, Tb, Dy, and Ho. Another potential limitation to the future use of the crystals is a compositional zoning found in the crystals with significant substitution in the scandium position. [ABSTRACT FROM AUTHOR]

Research into the use of sodium tetraalkoxyborate salts for different chemical applications including synthetic catalysis, hydrogen storage, or battery applications has been investigated, however, understanding of the structural, thermal and electrochemical properties of these salts has been lacking since the 1950s and 1960s. A review of the synthesis, as well as a thorough characterization using 1H NMR, 11B NMR, 13C{1H} NMR, FTIR, XRD, in situ XRD, DSC-TGA, RGA-MS, TPPA, and EIS has newly identified polymorphic phase changes for Na[B(OMe)4], K[B(OMe)4], Li[B(OMe)4], Na[B(OEt)4], Na[B(OBu)4], and Na[B(OiBu)4]. The crystal structure of K[B(OMe)4] was also solved in I41/a (a = 22.337(2) Å, c = 7.648(3) Å, V = 3815.6(4) Å3, ρ = 1.128(1) g cm−3). Ionic conductivity of the different salts was analyzed, however it was found that the compounds with longer alkyl chains had no measurable ionic conductivity compared to the shorter chained samples, Na[B(OMe)4] and K[B(OMe)4] with 9.6 × 10−8 S cm−1 and 1.6 × 10−7 S cm−1, at 114 °C respectively. [ABSTRACT FROM AUTHOR]

In this study, 13-Ni/ZrO2, 13-Ni3P/ZrO2, 13-Ni/SiO2, and 13-Ni3P/SiO2 catalysts were used in the hydrogenation of diethyl oxalate (DEO) to ethyl glycolate (Egly) to investigate the modulating effect of phosphorus. XRD, TEM, and FT-IR spectroscopy results indicated that phosphorus acts as a distributor of Ni metallic particles and thereby shows a segregation effect. The presence of P transformed the linkage of surface metals from an original Ni–Ni–Ni–Ni– to a P–Ni–P–Ni–P state, and FT-IR spectra showed that the former adsorbed CO in a combination of linear and bridging adsorption modes, whereas the latter predominantly in CO linear adsorption. Bridging adsorption occurs via dual sites and makes preliminary hydrogenation products less likely to detach from the catalyst surface, thus facilitating deep hydrogenation, while linear adsorption facilitates partial hydrogenation via rapid detachment of intermediate products such as Egly. Different loadings of Ni3P/SiO2 catalysts show incomplete phosphorylation with an increase in nickel loading, giving rise to a state of coexistence of Ni and Ni3P crystalline phases. This may lead to a coexistence of surface Ni–Ni–Ni–Ni and P–Ni–P–Ni–P and an increase in the corresponding bridging adsorption/linear adsorption ratios, making deep hydrogenation occur partially besides stepwise hydrogenation. [ABSTRACT FROM AUTHOR]

The development of modest and accurate electrochemical sensors for organic waste in water systems is of the highest priority. This study describes a method for synthesizing a Zn@ZrO2 nanoparticle decorated naringin (NG) nanocomposite (Zn@ZrO2/NG). Several techniques, such as XRD, FTIR, XPS, HR-SEM, EDX and HR-TEM, were used to investigate the morphology, structure and molecular properties of the Zn@ZrO2/NG nanocomposite. The electrochemical properties of Zn@ZrO2/NG were investigated using CV and DPV. The proposed sensor displayed strong linearity for p-nitrophenol (PNP) and o-nitrophenol (ONP) from 1 μM to 500 μM, with LOD of 1.14 μM and 1.03 μM, and sensitivity of 5.055 and 3.385 μA mM−1 cm−2, respectively. In addition, the fabricated sensor possesses good sensitivity, great reproducibility, and high stability for the detection of PNP and ONP. The enhanced sensitivity of the sensor towards the detection of PNP and ONP could pave way for the detection of PNP and ONP in real samples. [ABSTRACT FROM AUTHOR]

In this work, hollow spherical Pt-loaded WO3/ZnO heterostructured composites were prepared by a chemical liquid phase synthesis method. The morphology, crystal structure and components of the composites were characterized by SEM, TEM, XRD, XPS, etc. The sensing performance for various gases was also tested. Compared with the pristine WO3 (S = 44@225 °C, 50 ppm) gas sensor, the gas sensor that is functionalized with 1 wt% Pt and 0.5 mmol ZnO (1Pt/WZ-2) has a high response of 842–50 ppm at a relatively low temperature of 100 °C for TEA, with a quick response/recovery time of 34/120 s, a lower detection limit of 50 ppb, and good selectivity and moisture resistance. This study provides a highly efficient synthesis method of composite materials for TEA gas detection and the sensitivity mechanism is also discussed in detail. [ABSTRACT FROM AUTHOR]

A CdSiO3:Tb3+ deep trap phosphor was prepared by a sol–gel method. The structural information of the prepared phosphors was characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The optical properties of the Tb3+-doped CdSiO3 nanophosphors were investigated by fluorescence spectrophotometry. The afterglow time was more than 10.3 h in the case of Tb3+ doping. The stress–strain of this elastomer was enhanced after the phosphor was compounded with PDMS, and the energy release in the trap was accelerated under external force after applying stress to it, and this composite elastomer may possess mechanoluminescent properties. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of the double complex salts [Co(NH3)6]2[Cu(C2O4)2]3·4H2O and [Co(NH3)6]2[Cu(C2O4)2]3·6H2O was carried out. The process of thermal decomposition of synthesized compounds in reducing and inert atmospheres was studied with determination of the released gases composition, as well as intermediate and final decomposition products by ex situ XRD. The thermal decomposition of complex salts in reducing and inert atmospheres was studied by in situ powder X-ray diffraction on a laboratory diffractometer. The possibility of the formation of metastable solid solutions in the Co–Cu system with a maximum copper content up to 37 at% was demonstrated. [ABSTRACT FROM AUTHOR]

Hydrogels are promising materials, but because of their weak mechanical performance, further applications are limited. To enhance the strength of hydrogels, physical cross-linking was introduced by the use of hydrophobic unit diacetone acrylamide (DAAM) to form cross-linking points. The homopolymer of DAAM exhibited a high glass transition temperature above 80 °C, which was confirmed by DSC. The existence of the glassy and hydrophobic phases in the hydrogel was confirmed by XRD test results. The mechanical properties of the hydrogel were satisfactory, with a maximum tensile strength of 1.96 MPa, rapid recovery ability, satisfactory elasticity, and recyclability. A conductive hydrogel was prepared by introducing sodium ions, and it was used for human motion monitoring and is expected to be a promising material for flexible strain sensors. [ABSTRACT FROM AUTHOR]

A long afterglow material CaAl2O4:Eu2+,Pr3+ emitting blue light has been synthesized by a high-temperature solid-phase method. The effect of a series of preparation conditions on CaAl2O4:Eu2+,Pr3+ was first investigated using a single-factor preference method, and the optimal synthesis conditions were then obtained through orthogonal tests. The target products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), elemental mapping, fluorescence spectroscopy, and afterglow properties. The XRD results indicate the successful synthesis of CaAl2O4:Eu2+,Pr3+ materials, which was further verified by XPS analysis. The afterglow properties of the target products were further improved by doping with Nd3+ under optimum conditions obtained from orthogonal tests. The improvement was analyzed through XRD, fluorescence, afterglow and thermoluminescence analysis. The results indicate that doping with Nd3+ in CaAl2O4:Eu2+,Pr3+ materials significantly enhanced the afterglow properties, including an initial brightness of 2318 mcd m−2 and a duration of 26.5 hours. Thanks to its excellent blue long afterglow luminescence, the material is anticipated to have applications in energy-efficient lighting systems and solar energy systems. [ABSTRACT FROM AUTHOR]

The present work describes the synthesis of a material consisting of a bisimidazolium ionic liquid supported on graphene oxide. The prepared nanocomposite was characterized by different physicochemical techniques such as FT-IR, XRD, CHN, SEM, TEM and EDAX. The synthesized nanocomposite was further utilized as an effective heterogeneous catalyst for the synthesis of tetraketone derivatives, which are biologically significant, using dimedone and aryl aldehydes as the substrates at 50 °C and a green solvent. One of the tetraketone products has been confirmed by single crystal XRD. The catalyst displayed high reaction yields, facile separation, short reaction time, good stability and recoverability up to six consecutive reaction rounds with no discernible loss in its catalytic activity. [ABSTRACT FROM AUTHOR]

This work is the first attempt to prepare Nd1−xCaxUxPO4 monazite–cheralite with 0 < x ≤ 0.1 by a wet chemistry method. This method relies on the precipitation under hydrothermal conditions (T = 110 °C for four days) of the Nd1−xCaxUxPO4·nH2O rhabdophane precursor, followed by its thermal conversion for 6 h at 1100 °C in air or Ar atmosphere. The optimized synthesis protocol led to the incorporation of U and Ca in the rhabdophane structure. After heating at 1100 °C for 6 h in air, single-phase monazite–cheralite samples were obtained. However, α-UP2O7 was identified as a secondary minor phase in the samples heated under Ar atmosphere. The U speciation in the samples converted in an oxidising atmosphere was carefully characterized using synchrotron radiation by combining HERFD-XANES and XRD. These results showed the presence of a minor secondary phase containing hexavalent uranium and phosphate with a stoichiometry of U : P = 0.78. This highly labile uranyl phosphate phase incorporated 21 mol% of the uranium initially precipitated with the rhabdophane precursor. This phase was completely removed by a washing protocol. Thus, single-phase monazite–cheralite was obtained through the wet chemistry route described in this work with a maximum U loading of x = 0.08. [ABSTRACT FROM AUTHOR]

Reactions of N,N′,N′′-tris(3-methylpyridyl)trimesic amide (L) and Cd(OAc)2·2H2O with various polycarboxylic acids afforded {[Cd2(L)(1,4-BDC)2(H2O)2]·2H2O}n (1,4-H2BDC = benzene-1,4-dicarboxylic acid), 1, {[Cd(L)(4,4′-BDC)(H2O)]·H2O}n (4,4′-H2BDC = biphenyl-4,4′-dicarboxylic acid), 2, and {[Cd3(L)2(1,3,5-BTC)2(H2O)6]·15H2O}n (1,3,5-H3BTC = benzene-1,3,5-tricarboxylic acid), 3, which have been structurally determined by using single-crystal X-ray diffraction. Complexes 1–3 display 2D layers with (3·82)2(32·4)2(36·44·52·84·96·105·11), (44·62)-sql and (42·124)3(43)4-3,4L129 topologies, respectively, indicating that the identities of the polycarboxylate ligands involving length and shape play important roles in determining the structural diversity. Complexes 1 and 2 show stabilities in various solvents and display high selectivity toward sensing of Fe3+ ions with low detection limits and good reusability of up to five cycles. [ABSTRACT FROM AUTHOR]

In the present work, copper whitlockite (Cu-WH, Ca18Cu2(HPO4)2(PO4)12) was successfully synthesized and comprehensively characterized, founding the base knowledge for its future studies in medicine, particularly for bone regeneration. This material is a copper-containing analog of the well-known biomineral magnesium whitlockite (Mg-WH, Ca18Mg2(HPO4)2(PO4)12). The synthesis of powders was performed by a dissolution–precipitation method in an aqueous medium under hydrothermal conditions. Phase conversion from brushite (CaHPO4·2H2O) to Cu-WH took place in an acidic medium in the presence of Cu2+ ions. Optimization of the synthesis conditions in terms of medium pH, temperature, time, Ca/Cu molar ratio and concentration of starting materials was performed. The crystal structure of the synthesized products was confirmed by XRD, FTIR and Raman spectroscopy, 1H and 31P solid-state NMR, and EPR. Morphological features and elemental distribution of the synthesized powders were studied by means of SEM/EDX analysis. The ion release in SBF solution was estimated using ICP-OES. Cytotoxicity experiments were performed with MC3T3-E1 cells. The study on thermal stability revealed that the synthesized material is thermally unstable and gradually decomposes upon annealing to Cu-substituted β-Ca3(PO4)2 and Ca2P2O7. [ABSTRACT FROM AUTHOR]

Single crystals of two new intermetallic phases Sm2Mn1−xGa6−yGey (x = 0.1–0.3, y = 0.6–1.0) and Sm4MnGa12−yGey (y = 3.0–3.5) were grown using a self-flux technique. According to single crystal X-ray diffraction data, Sm4MnGa12−yGey is characterised by the Y4PdGa12 structure type (a ∼ 8.65 Å; Im3¯m), while Sm2Mn1−xGa6−yGey formally adopts the K2PtCl6 structure type (a ∼ 8.71 Å; Fm3¯m). The general features of both compounds with rather similar crystal structures are represented by the alternation of empty and Mn-filled p-element octahedra, the order of which is determined by the Mn concentration. The diffraction data for Sm2Mn1−xGa6−yGey reveal a large concentration of Mn vacancies (x ∼ 0.3), which affects adjacent Ga/Ge atoms leading to their shift towards the vacancy. Both compounds demonstrate two ferromagnetic-like transitions and the presence of two interacting Mn and Sm magnetic sublattices. The Mn sublattice orders at TC1 of 143 K and 318 K, while the Sm one orders at lower temperatures at TC2 of 50 K and 280 K for Sm4MnGa8.6Ge3.4 and Sm2Mn0.74Ga5.1Ge0.9, respectively. The increase in Mn content not only increases the ordering temperatures, but also dramatically decreases the coercivity μ0HC from 230 mT to just 6.5 mT at 2 K. Despite the presence of two magnetically active sublattices in Sm2Mn0.74Ga5.1Ge0.9, the magnetic entropy change is quite low and only reaches 0.3 J kg−1 K−1 at T = 300 K and μ0H = 5 T, while the estimated relative cooling power (RCP) is about 36 J kg−1 at 5 T. [ABSTRACT FROM AUTHOR]

Herein, hollow hZrO2/g-C3N4 composite photocatalysts were successfully fabricated using polymethylacrylic acid (PMAA) nanospheres as sacrificial templates via reflux-precipitation polymerization and subsequent ZrO2 layer coating by sol–gel method over PMAA nanospheres, calcining process, and forming composites with g-C3N4 in sequence. The formation mechanism of the unique composites was proved by FESEM, TEM, XPS, XRD, and EDX mapping characterizations. The photodegradation tests of methylene blue (MB) and ciprofloxacin (CIP) were used to investigate the photocatalytic activity. The results revealed that hZrO2/g-C3N4 exhibited significantly boosted photocatalytic activity for degrading 99.7% methylene blue and 81.5% ciprofloxacin in 120 min under simulated sunlight irradiation (Xe lamp, 500 W), which was much better than that of hZrO2 (42.1% for MB and 19.1% for CIP). The enhanced performance is presumably attributed to the synergetic interaction of the two components and the efficient separation of the photoproduced electron–hole pairs between ZrO2 and g-C3N4, which was verified using photocurrent and EIS characterizations. On the basis of the scavenging studies of free radicals (e−, h+, ˙O2−, and ˙OH), the mechanism of the boosted photocatalytic activity was proposed. More significantly, the composites presented excellent reusability confirmed by cyclic photocatalytic degradation experiments, which is crucial for the sustainable and green applications of photocatalysts. [ABSTRACT FROM AUTHOR]

In order to extend the use of supported ionic liquids as effective heterogeneous catalysts, in this research, a novel FSM-16 supported Brønsted acidic ionic liquid (FSM-16-IL-SO3H) was synthesized and characterized using various techniques such as FT-IR, TGA, SEM, EDX, XRD, and BET. The prepared catalyst was used as a new, environmentally friendly, and recyclable catalyst for the synthesis of biscoumarin derivatives through the reaction of aromatic aldehydes and 4-hydroxycoumarin with short reaction times and high yields. [ABSTRACT FROM AUTHOR]

Ag lattice doped In2O3 with a mesoporous structure was synthesized through a combination of hydrothermal and calcination methods. The structural and morphological characteristics were assessed using XRD, SEM, TEM, TGA, BET, and XPS analyses. Gas sensing measurements revealed that the 7.0 mol% Ag-doped In2O3 sensor displayed a response of 420 towards 100 ppm ethanol at 140 °C, which was 19 times higher than that of the pure In2O3 gas sensor. Density functional theory calculations indicated that Ag-doped In2O3 exhibited enhanced adsorption performance, higher adsorption energy, and electron transfer, resulting in higher sensitivity to ethanol. These findings were also supported by the electronic band structure, work function, and DOS analyses. These results indicated that the Ag doped mesoporous In2O3 has high potential for the preparation of high-performance ethanol sensors in practical applications. [ABSTRACT FROM AUTHOR]

A series of luminescent Cu4I4 clusters with stair-step, cubane, and octahedral geometries supported by a novel type of cyclic As,N-ligand, pyridyl-containing 10-phenoxarsines, were synthesized and characterized by NMR spectroscopy, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction analysis. An unusual arrangement of As,N-bidentate and μ2-iodo ligands was found in the octahedral cluster. The structural diversity of the Cu(I) complexes is reflected in their photophysical properties: the phosphorescence spectra of the compounds display emission in a broad spectral range of 495–597 nm. The complex with the Cu4I4L2 stoichiometry bearing a stair-step Cu4I4 core demonstrates temperature-dependent dual emission. The luminescence properties of all complexes were rationalized by DFT calculations. [ABSTRACT FROM AUTHOR]

Until now, double perovskite tellurates have not been reported to exhibit inherent NIR photoluminescence. Therefore, the current study's revelation of inherent NIR luminescence in SrLaLiTeO6 double perovskite centered at 970 nm under 340 nm excitation is particularly intriguing. This phenomenon is attributed to the photoluminescence of Te4+ ions. This study also examines the NIR luminescence of Cr3+–Yb3+ co-doped SrLaLiTeO6. The host and SrLaLiTeO6:3%Cr3+, y%Yb3+ (y = 1, 2, 4, 6, 8, 10 mol%) were synthesized using the solid-state ceramic route. The successful incorporation of Cr3+ and Yb3+ ions into the host lattice was confirmed through XRD, Raman, and diffuse reflectance spectral analyses. Under 270 nm excitation, the photoluminescence (PL) of SrLaLiTeO6:Cr3+ exhibits a blueshift of the PL band to 965 nm due to the 4T2(4F) → 4A2g(4F) emission component of Cr3+ ions. The excited-state lifetime of SrLaLiTeO6:0.5%Cr3+ was measured at 36 μs, but this decreased to 26 μs as the Cr3+ concentration reached 10 mol%, primarily due to the enhancement of non-radiative energy transfer between Cr3+ ions. Incorporating Yb3+ into the system results in additional spectral lines with an enhanced intensity in the range of 970 nm to 1125 nm when excited at 270 nm. These emission lines correspond to the 2F5/2 → 2F7/2 transitions of Yb3+ ions, indicating an efficient energy transfer from Cr3+ to Yb3+. Furthermore, the study also reveals that Yb3+ emission is observed even without Cr3+ ions in SrLaLiTeO6 under 340 nm excitation, suggesting the possibility of energy transfer from the host to Yb3+ ions. The thermal stability and crystal field parameters of the synthesized phosphors are also explained in detail. To explore the potential of these phosphors in practical applications, phosphor-converted NIR LEDs were fabricated using SrLaLiTeO6, SrLaLiTeO6:3% Cr3+, and SrLaLiTeO6:3% Cr3+, 1%Yb3+. [ABSTRACT FROM AUTHOR]

One-dimensional manganese selenide@carbon nanofibers (MnSe@CNF) were synthesized by means of an electrospinning technique involving in situ selenization. The synthesized MnSe@CNF was characterized using various material characterization techniques. The surface morphology of MnSe@CNF was investigated using field-emission scanning electron microscopy and further substantiated with high-resolution transmission electron microscopy analyses. A sodium-ion battery was constructed using MnSe@CNF as the anode, which exhibited an enhanced specific capacity of 725 mA h g−1 at 0.1C rate with a better rate capability. Furthermore, the Na+ charge storage kinetics was evaluated using Dunn's method. It was revealed that Na+ charge storage was a combination of diffusion storage and significant capacitive storage. Explicitly, the deconvoluted current response at the peak potential region of the cyclic voltammetry profile affirmed that Na+ charge storage is dominated by diffusion, whereas the non-peak potential region had a blend of capacitance and diffusion. Further, the postmortem analyses using the XRD performed at different depths-of-discharges (DoDs) confirmed the occurrence of the conversion/reconversion reaction and the robust stability of the MnSe@CNF anode. MnSe@CNF underwent the diffusive conversion/reconversion reaction while the carbon nanofibre facilitated the capacitive Na+ charge storage, leading to enhanced specific capacity. [ABSTRACT FROM AUTHOR]

In this study, a series of structurally rigid cyclooctyl-fused iminopyridine iron complexes, [L2FeCl][FeCl4] and [2L3Fe][Cl][3FeCl4], was synthesized via a one-pot method and investigated as precatalysts in conjunction with methylaluminoxane for isoprene (Ip) polymerization. Combined characterization through FTIR analysis, elemental analysis and single crystal XRD analysis fully verified the structure of these complexes. The most active iron complex, FeH, exhibited a trisligated nature, with its cation adopting an octahedral geometry around the metal center. In contrast, all the other iron complexes (Fe2Me, Fe2Et, Fe2iPr, Fe3Me, Fe2Et,Me) displayed bisligated configurations, with distorted trigonal bipyramidal geometry of cations. During isoprene polymerization, the extent of steric hindrance of the ligand framework exerted a significant impact on catalytic performance. The FeH precatalyst with less steric hindrance demonstrated excellent performance, producing high molecular weight polyisoprenes with conversions exceeding 99% for 4000 equiv. of monomer. Even at very low catalyst loadings, as low as 0.0025 mol% (Fe/Ip), the polymerization of isoprene could proceed smoothly with an exceptionally high activity of 4.0 × 106 gPI (molFe, h)−1. Moreover, this precatalyst exhibited good thermal stability, maintaining high activity levels (typically 105 gPI (molFe, h)−1) across a broad temperature range from −20 °C to 100 °C. Additionally, by adjusting steric substituents and the reaction temperature, the 1,4/3,4 regioselectivity could be modulated from 9/91 to 69/31 while maintaining a high stereoselectivity of cis-1,4 structures (cis/trans: >99/1). [ABSTRACT FROM AUTHOR]

Halide perovskites have high photoelectric conversion efficiency, making them promising candidates for photocatalysis. However, their toxic and unstable nature limits their applications. Here, we successfully synthesised three hybrid Bi-based halide perovskites: (HTMG)3Bi2Br9 (1), (HEI)2BiBr5 (2) and (HTMA)3Bi2Br9 (3). X-ray single-crystal diffraction analysis shows that they all contained 0D structures composed of isolated Bi–Br clusters. The three compounds showed excellent degradability and cycling stability for Sudan III dissolved in ethanol under simulated sunlight. In addition, the photocatalytic degradation performance of four Bi-based halide perovskites previously reported by our group is also characterised and summarised in this work. [ABSTRACT FROM AUTHOR]

Salt metathesis of RECl3 with 1 equiv. of FcC5Me4Li (Fc = ferrocenyl group), followed by the addition of 2 equiv. of LiCH2C6H4NMe2-o in THF at room temperature gave the ferrocenyl functionalized half-sandwich rare-earth metal bis(o-dimethylaminobenzyl) complexes (FcC5Me4)RE(CH2C6H4NMe2-o)2 (RE = Sc (1), Y (2), Lu (3)) in good isolated yields. These complexes were well-characterized by elemental analysis, FT-IR spectroscopy and NMR spectroscopy. The solid state structure of complex 1 was determined by single-crystal X-ray diffraction. Electrochemical study showed that the Fe(II / III) couple of the ferrocenyl moiety in complexes 1–3 was reversible. ε-Caprolactone polymerization initiated by complex 2 proceeded in a controlled fashion. However, upon addition of AgBF4 and Cp2Co, the catalytic performance could not be restored and reversible switching was highly unlikely. [ABSTRACT FROM AUTHOR]

This study is concerned with the iridium–palladium (Ir–Pd) binary alloy as a counter electrode (CE) for DSSC. The CE was prepared using the liquid phase deposition (LPD) technique. The influence of the concentration of hydrogen hexachloroiridate(IV) hydrate (H2Cl6Ir·H2O) on the properties and the performance of the device was investigated. The source of iridium was H2Cl6Ir·H2O. XRD analysis confirmed that the dominant phase of Ir–Pd existed in the sample. The grain size of Ir–Pd increased with the increase in the concentration of H2Cl6Ir·H2O until an optimum concentration of 0.7 mM was reached. The % wt of Ir was found to increase with the concentration of H2Cl6Ir·H2O. The device utilizing Ir–Pd CE with 0.7 mM H2Cl6Ir·H2O demonstrated the highest power conversion efficiency (PCE) of 5.84%, beating that of the device with Pt CE having a PCE of 5.04%. This is because the device possesses the lowest charge transfer resistance (Rct), highest recombination resistance (Rcr), and longest carrier lifetime (τ), and the device possesses the highest reduction current (Jpc) and incident-photon conversion efficiency (IPCE). The PCE was significantly affected by Ir content in the binary alloy of Ir–Pd. According to the PCE result, Ir–Pd CE was found as a suitable substitution for Pt as CE for the device. [ABSTRACT FROM AUTHOR]

This study highlights the successful synthesis of a potential ligand, 2,2′,2′′,2′′′-((pyridine-2,6-diylbis(methylene))bis(azanetriyl))tetraacetamide (PATA), along with its corresponding Co(II) and Ni(II) complexes for paraCEST-based agents. X-ray diffraction data confirmed that both the complexes are six coordinated with distorted octahedral geometries, but only the [Co(PATA)]2+ complex has a good structural feature to show paraCEST activity. After a thorough characterization of the ligand and both of its complexes, various studies, including solution-state magnetic properties, redox properties, temperature, and pH variation studies, were carried out. [Co(PATA)]2+ remained inert in the presence of competing ions, under acidic conditions, at high temperatures, and in the physiological pH range. The paraCEST response of [Co(PATA)]2+ has been measured in the presence of HEPES buffer medium, and a high paraCEST feature was discovered at both 37 and 25 °C. The pH variation paraCEST studies were carried out and the exchange rate constant of the probe at 37 and 25 °C was also determined. However, due to the fast exchange of water protons, the [Ni(PATA)(OH2)]2+ complex remained inactive in the CEST process. [ABSTRACT FROM AUTHOR]

Seven heterometallic iodoantimonates with the general formula (Cat)2{[Sb2M2I10]} (M = Cu(I) (1–6), Ag(I) (7)) were prepared. X-ray diffraction data indicate that these compounds are the first Sb(III) representatives of the structural type previously known only for heterometallic iodobismuthates(III). In 3 and 4, halogen-substituted cations form halogen bonds with the heterometallic halometalate chain. 1–7 show prominent thermal stability. The estimated optical band gaps lie between 2.16 and 2.40 eV. As in heterometallic iodobismuthates, incorporation of Cu+ rather than Ag+ provides a much lower band gap. [ABSTRACT FROM AUTHOR]

In this work, we investigate the vapor-assisted synthesis of the metal–organic framework MOF-74 starting from three metal oxides (ZnO, CoO, and MgO). Depending on the nature of the added vapor (H2O, DMF, DMSO), the metal oxide, and the temperature, the outcome of the reaction can be directed towards the desired porous phase. Ex situ and in situ XRD measurements reveal the formation of an intermediate phase during the reaction of MgO with H4dobdc, while the MOF-74 phase forms directly for ZnO and CoO. The reduced CO2 uptake of the resulting materials compared to solvothermally prepared MOFs might be offset by the convenience of the presented route and the promise of a high space time yield. [ABSTRACT FROM AUTHOR]

In this study, a novel mononuclear complex In(H2nha)3 (1) (H3nha = 3-hydroxy-2-napthanoic hydroxamic acid) was synthesized and characterized. Single-crystal X-ray diffraction revealed that 1 possesses a centrosymmetric structure consisting of one In(III) and three partially deprotonated ligands. Luminescent studies suggested that 1 could selectively and sensitively recognize Al3+ and B4O72− through fluorescence enhancement effect, even could be directly observed with naked eyes under 365 nm ultraviolet lamp, and their detection limits can be as low as 1.3 and 6.2 μM, respectively. Moreover, the mechanism of their fluorescence enhancement was explored. [ABSTRACT FROM AUTHOR]

High-pressure single crystal X-ray diffraction has been used to probe framework–guest interactions in the Co-based metal–organic framework ZIF-67 during compression in 4 : 1 MeOH : EtOH and liquid nitrogen (LN2) pressure-transmitting media. On increasing pressure, the structure undergoes a gate-opening phase transition, characterised by rotation of the 2-methylimidazolate ligand, at 1.57 GPa in MeOH : EtOH and at 0.43 GPa LN2. Adsorption of N2 occurred progressively with increasing pressure into 6 adsorption sites and resulted in the first documented instance of pressure-induced solvatochromism in ZIF-67. [ABSTRACT FROM AUTHOR]

Two LnIII complexes Ln(HTMSA)3(H2O)2·5.5H2O (Ln = Dy (1) and Tb (2), H2TMSA = 5-azotriazolyl-3-methoxysalicylaldehyde) and two MnII–LnIII clusters [Mn(H2O)6][MnLn2(TTMSA)4(HTTMSA)2(H2O)6]·4H2O (Ln = Dy (3) and Tb (4), H2TTMSA = 5-azotetrazolyl-3-methoxysalicylaldehyde) have been synthesized and structurally characterized. Single-crystal X-ray diffraction reveals that 1 and 2 are isostructural complexes in which the LnIII ions are surrounded by six oxygen atoms from three chelate HTMSA ligands and two oxygen atoms from two coordinated water molecules forming a distorted square-anti-prismatic geometry. In complexes 3 and 4, the MnII ions adjust two LnIII mononuclear anion clusters into tri-nuclear LnIII–MnII–LnIII anion clusters, with an additional [Mn(H2O)6]2+ as a counter ion to maintain the electroneutrality of the compound. Magnetic studies reveal that all the complexes 1–4 show nonzero out-of-phase signals, indicating single-molecule magnet behavior. The photoluminescence spectra of all the complexes were investigated and are discussed in detail. [ABSTRACT FROM AUTHOR]

Aqueous zinc–sodium hybrid batteries with a Prussian blue cathode have been extensively studied in recent years. However, less research has been conducted on low-cost ferric ferricyanide (FeFe(CN)6) cathode materials. Considering that both Zn2+ and Na+ can be reversibly embedded in FeFe(CN)6 crystals, here we focus on mixed electrolytes with different concentrations of ZnSO4 and Na2SO4 in deionized water to explore the preference of FeFe(CN)6 towards Zn2+ and Na+. As a result, by using 0.1 M ZnSO4 + 1 M Na2SO4 electrolyte, a superior battery performance is obtained, which reveals that the co-function of Zn2+ and Na+ in this electrolyte promotes Zn//FeFe(CN)6 cells to exert a superior specific capacity. In this work, FeFe(CN)6 is synthesized by a co-precipitation method and is analyzed by XRD, SEM, etc., and then used as the cathode material in Zn–Na hybrid batteries. Cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) tests show that FeFe(CN)6 in 0.1 M ZnSO4 + 1 M Na2SO4 electrolyte delivers the highest discharge/charge capacities of 165.2/165.9 mA h g−1 (theoretical specific capacity: 212.2 mA h g−1) at a 0.1 C current density, with good capacity retention of 84% after 200 cycles at 15 C, outperforming many of the reported Zn–Na hybrid cells. [ABSTRACT FROM AUTHOR]

In the fairly modest temperature and pressure regime of 0–2 GPa and 200–295 K, 2,2,2-trifluoroethanol (TFE) exhibits a remarkable degree of polymorphism, with the observation of four ordered phases (forms 1–4) and a cubic plastic phase (form 5). The ordered phases are characterised by hydrogen-bonded chains, with the crystal structures of the three high-pressure forms (forms 2, 3 and 4) based on the same hydrogen-bonded catemeric motif. The structures and relationships between these phases were determined using a combination of high-pressure single-crystal X-ray diffraction, at ambient temperature, and a series of high-pressure neutron powder-diffraction experiments to ∼6 GPa at 295 K, 245 K and 200 K. As well as allowing the determination of the relative compressibilities of the phases, the neutron powder-diffraction studies also provided a preliminary mapping of the surprisingly rich phase diagram of TFE. [ABSTRACT FROM AUTHOR]

Heterostructure NaMnO2–Li0.5Mn2O4 cathode materials were prepared by adjusting the molar ratio of sodium in the materials by a solid phase method. X-ray diffraction (XRD) analysis showed that the prepared samples were a layered-spinel heterostructure NaMnO2–Li0.5Mn2O4. The lattice fingerprint region of NaMnO2–Li0.5Mn2O4 was studied by electron microscopy, and the results showed the (111) plane of Li0.5Mn2O4 and the (001) plane of NaMnO2. The heterostructure 0.5NaMnO2–0.5Li0.5Mn2O4 exhibits superior high-rate capability and excellent cycling performance. The proposed heterostructure 0.5NaMnO2–0.5Li0.5Mn2O4 cathode is investigated by in situ XRD and impedance analysis. The rate of discharge of heterostructure 0.5NaMnO2–0.5Li0.5Mn2O4 was 108.8 mA h g−1 at 500 mA g−1. The initial discharge of 0.5NaMnO2–0.5Li0.5Mn2O4 was 61.69 mA h g−1, and after 1000 cycles the discharge capacity remained 51.13 mA h g−1 at a current of 2 A g−1. The heterogeneous structure combines the advantages of high capacity of the layered structure NaMnO2 and the structural stability of the spinel Li0.5Mn2O4, which exert a synergistic effect and improve the electrochemical performance of the lithium-free layered NaMnO2 cathode material. [ABSTRACT FROM AUTHOR]

Three new Co(II)-based coordination polymers, namely [Co(L)]n (1), [Co(H2L)1.5(1,10-phen)(H2O)2]n (2), and {[Co2(L)(dpa)(H2O)2]·(H4L)0.5}n (3) (H4L = 5,5′-(ethene-1,2-diyl)diisophthalic acid, 1,10-phen = 1,10-phenanthroline, dpa = (E)-1,2-di(pyridin-4-yl)diazene), were solvothermally synthesized and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, and magnetic studies. 1 and 3 display a 3D framework with (4,6)-connected CrB-type topology, and 2 displays a 1D chain built by the unprotonated H2L linker. The magnetic studies indicated that CPs 1–3 show the presence of weak antiferromagnetic interactions within the Co(II) units. [ABSTRACT FROM AUTHOR]

While most of the reports on NH3 gas sensors are either based on metal oxide composites with other 2D materials, polymers or noble metals or involve multi-step-based synthesis routes, this work is the first report on a pristine ternary metal oxide, 2D NiCo2ZnO4 nanoflake based room-temperature (RT) NH3 gas sensor. The 2D NiCo2ZnO4 nanoflakes were prepared by a one-step hydrothermal method. FESEM and TEM images displayed micro-flower like morphologies, containing vertically aligned interwoven porous 2D nanoflakes, whereas XPS and XRD data confirmed the successful growth of this ternary metal–oxide. This sensor revealed a good response, repeatability, linearity (R2 = 0.9976), a low detection limit of 3.024 ppb, and a response time of 74.84 s with excellent selectivity towards NH3 over six other VOCs. This improved performance of the sensor is ascribed to its large specific surface area (127.647 m2 g−1) resulting from the 2D nanoflake like structure, good electronic conductivity, variable valence states and abundant surface-active oxygen of NiCo2ZnO4. Thus, this highly selective 2D NiCo2ZnO4 based RT NH3 gas sensor can be an attractive solution for the fabrication of next-generation NH3 gas sensors. [ABSTRACT FROM AUTHOR]

The synthesis and characterisation of eleven different 2-(thienyl)quinoxaline species that incorporate different points of functionality, including at the thiophene or quinoxaline rings, are described. These species display variable fluorescence properties in the visible region (λem = 401–491 nm) depending upon the molecular structures and extent of conjugation. The series of 2-(thienyl)quinoxaline species were then investigated as cyclometalating agents for Ir(III) to yield [Ir(C^N)2(bipy)]PF6 (where C^N = the cyclometalated ligand; bipy = 2,2′-bipyridine). Eight complexes were successfully isolated and fully characterised by an array of spectroscopic and analytical techniques. Two Ir(III) examples were structurally characterised in the solid state using single crystal X-ray diffraction; both structures confirmed the proposed formulations and coordination spheres in each case showing that the thiophene coordinates via a Ir–C bond. The photophysical properties of the complexes revealed that each complex is luminescent under ambient conditions with a range of emission wavelengths observed (665–751 nm) indicating that electronic tuning can be achieved via both the thienyl and quinoxaline moieties. [ABSTRACT FROM AUTHOR]

Laccase is an effective biocatalyst for the degradation of persistent phenolic pollutants. However, its high cost and instability under harsh operational conditions hinder its applications. Hence a peptide/nucleotide-matrix-free laccase mimetic nanozyme would be attractive. Herein, MoS2/Cu is synthesized as a laccase mimic for catalytic oxidation of phenolic pollutants. Characterization of the nanozyme by SEM-EDX, XRD, and XPS confirmed the presence of multi-oxidation state copper on MoS2 which is consistent with the composition of natural laccase. The laccase mimetic activity of MoS2/Cu was examined by using 2,4-dichloro phenol as a substrate which oxidized to form a colored product with 4-aminoantipyrine (λmax = 510 nm). Surprisingly, MoS2/Cu showed 55.6% higher activity than pristine Cu NPs at pH 7, indicating the role of MoS2 as an effective scaffold. The catalytic reaction exhibited a lower Km (0.11 mM) than that reported for natural laccase. MoS2/Cu showed improved stability retaining 84.63% of its activity at 90 °C and lost only 10.93% of its activity after one month. Furthermore, it exhibited remarkable activity in the presence of different salts and alcohol stress. Notably, the nanozyme converted over 92% of phenolic substrates in 9 h. The results imply a robust performance for the remediation of phenolic compounds. [ABSTRACT FROM AUTHOR]