Thermoelectric properties of polycrystalline palladium sulfide

Measurement of the electrical, thermal, and structural properties of palladium sulfide (PdS) has been conducted in order to investigate its thermoelectric performance. A tetragonal structure with the space group P4₂/m for PdS was determined from X-ray diffraction measurement. The obtained power factor of 27 μW cm⁻¹ K⁻² at 800 K is the largest value obtained for the transition metal sulfides studied so far. The maximum value of the dimensionless figure of merit is 0.33 at 800 K. These results indicate that binary bulk PdS has promising potential for good thermoelectric performance.

Measurement of the electrical, thermal, and structural properties of palladium sulfide (PdS) has been conducted in order to investigate its thermoelectric performance.     

Hydrothermally synthesized poorly-crystalline binary oxides with ZrW2O8 composition: preparation,structural analysis,and catalytic activity for the alkylation of anisole with benzyl alcohol

Hydrothermally synthesized poorly-crystalline metastable Zr–W binary hydroxide (W/Zr = 2), after calcination, was confirmed to be a strong solid acid catalyst to promote the alkylation of anisole with benzyl alcohol. The preparation conditions, structure of the as-prepared catalysts and the calcined hydroxides were investigated using XRD, nitrogen adsorption isotherms, TG-DTA, and XANES/EXAFS techniques. The crystalline phase was controlled by the hydrochloric acid concentration used for preparing a mother gel, and 5–9 M HCl was suitable for preparing the active phase. The tungsten species exists as a six-valent WO₆ distorted octahedron connected with the ZrO₇ unit via corner-sharing linkages. The incompleteness of the network structure is suggested to be responsible for the solid acidity.

Hydrothermally synthesized poorly-crystalline metastable Zr–W binary hydroxide (W/Zr = 2), after calcination, was confirmed to be a strong solid acid catalyst to promote the alkylation of anisole with benzyl alcohol.     

Photoabsorption markers of pressure-induced phase changes in small mercury clusters. A case study on Hg8

Photoabsorption spectra of Hg₈ have been calculated at various cluster temperatures and external pressures. A diatomics-in-molecules method has been used to model cluster electronic structure and classical isothermal–isobaric Monte Carlo simulations have been employed for sampling representative cluster configurations. Contributions of different structural isomers of the Hg₈ cluster have been analyzed and related to structural transitions in the cluster, particularly those induced by an increased pressure.

Evolution of low-temperature Hg₈ absorption spectrum with increased external pressure.     

Design and formulation of polymeric nanosponge tablets with enhanced solubility for combination therapy

Three drugs namely caffeine, paracetamol, and aceclofenac are commonly used for treating various acute and chronic pain related ailments. These 3 drugs have varied solubility profiles, and formulating them into a single tablet did not have the desired dissolution profile for drug absorption. The objective of the present research was to tailor the drug release profile by altering drug solubility. This was achieved by loading the drug into nanosponges. Here, three-dimensional colloidal nanosponges were prepared using β-cyclodextrin with dimethyl carbonate as a cross-linker using the hot-melt compression method. The prepared nanosponges were characterized by FTIR, ¹H NMR spectroscopy, DSC, XRPD studies and SEM. The FTIR and DSC results obtained indicated polymer-drug compatibility. The ¹H NMR spectroscopy results obtained indicated the drug entrapment within nanosponges with the formation of the inclusion complex. XRPD studies showed that the loaded drug had changed crystalline properties altering drug solubility. SEM photographs revealed the porous and spongy texture on the surface of the nanosponge. Box–Behnken experimental design was adopted for the optimization of nanosponge synthesis. Among the synthesized nanosponges containing paracetamol, aceclofenac and caffeine, batch F3–P31, F3–A31 and F3–C31 were considered optimized. Their particle size was 185, 181 and 199 nm with an entrapment efficiency of 81.53, 84.96, and 89.28% respectively. These optimized nanosponges were directly compressed into tablets and were studied for both pre and post-compression properties including in vitro drug release. The prepared tablet showed desired drug dissolution properties compared to the pure drug. The above outcomes indicated the applicability of nanosponges in modulating the drug release with varied solubility for combination therapy.

Polymeric nanosponges as potential carriers for successful combination therapy of poorly soluble drugs (paracetamol, aceclofenac, caffeine).     

Highly efficient conversion of CO2 to cyclic carbonates with a binary catalyst system in a microreactor: intensification of “electrophile–nucleophile” synergistic effect

An intensification of the “electrophile–nucleophile” synergistic effect was achieved in a microreactor for the coupling reaction of CO₂ and epoxides mediated by the binary Al complex/ternary ammonium salt catalyst system. The microreactor technology is proven to be a powerful tool for the preparation of cyclic carbonates with an improved reaction rate and a wide substrate scope.

An intensification of the “electrophile–nucleophile” synergistic effect was achieved in a microreactor for the coupling reaction of CO₂ and epoxides mediated by the binary Al complex/ternary ammonium salt catalyst system.     

Alcohol functionality in the fatty acid backbone of sphingomyelin guides the inhibition of blood coagulation

Cell-surface sphingomyelin (SM) inhibits binary and ternary complex activity of blood coagulation by an unknown mechanism. Here we show the OH functionality of SM contributes in forming the close assembly through intermolecular H-bond and through Ca²⁺ chelation, which restricts the protein–lipid/protein–protein interactions and thus inhibits the coagulation procedure.

Cell-surface sphingomyelin (SM) inhibits binary and ternary complex activity of blood coagulation.     

Stabilization of two conformers via intra- or inter-molecular hydrogen bonds in a dinuclear vanadium(v) complex with a pendant Schiff base: theoretical insight

A dinuclear vanadium(v) complex, (μ-O)₂[V(O)(L)]₂, [where HL = 2-methoxy-6-((2-(2-hydroxyethylamino)ethylimino)methyl)phenol] has been synthesized and characterized by spectral and elemental analysis. A single crystal X-ray diffraction study confirms it structure. Two different conformations, stabilized via either intra- or inter-dinuclear hydrogen bonding interactions, co-exist in the solid-state structure. The energies of these intra- or inter-dinuclear hydrogen bonding interactions have been estimated by Density functional theory (DFT) calculations. A ‘Non-covalent interaction’ (NCI) plot has also been used to characterize these interactions.

Two different hydrogen bonded conformers coexist in a synthesized dinuclear oxovanadium(v) Schiff base. Density functional theory (DFT) calculations were utilized to calculate the energies involved in two different conformers.     

Novel mesoporous Ag@SiO2 nanospheres as a heterogeneous catalyst with superior catalytic performance for hydrogenation of aromatic nitro compounds

Mesoporous core–shell structure Ag@SiO₂ nanospheres are constructed to prevent Ag nanoparticles from aggregation during the hydrogenation reaction. The prepared catalyst shows superior catalytic performance for hydrogenation of nitro compounds with 100% conversion and selectivity without any by-products, which also indicates good recycling performance for several times use.

Mesoporous core–shell structure Ag@SiO₂ nanospheres are constructed to prevent Ag nanoparticles from aggregation during the hydrogenation reaction.     

Design of organic structure directing agents to control the synthesis of zeolites for carbon capture and storage

We have de novo designed organic structure directing agents (OSDAs) for zeolites that have been predicted to be effective materials for carbon capture and storage. The zeolites were selected for their reduced parasitic energy when used as CO₂ adsorbants in a pressure–temperature swing process in coal- or natural gas-fired power plants. Synthetically accessible OSDAs were designed for five known and two theoretical frameworks.

Zeolites more efficient at carbon capture than scrubbing with aqueous monoethanolamine, and the best OSDAs designed for the synthesis of each.     

Infiltration of biomineral templates for nanostructured polypyrrole

Biomineral templates like sea urchin spine, nacre or eggshell were applied in the polymerisation of pyrrole. The insufficient infiltration of pyrrole into the CaCO₃ structure of the biomineral templates was improved using three different and universally applicable approaches and the electrochemical properties of the received polypyrrole were examined.

The insufficient infiltration of pyrrole into the CaCO₃ structure of biomineral templates was improved using three universally applicable approaches.     

Synergy ascension of SnS/MoS2 binary metal sulfides on initial coulombic efficiency and stable capacity for lithium storage

Numerous efforts have been devoted to capability improvement and cycling stability in the past decades, and these performances have been significantly enhanced. Low initial coulombic efficiency is still a problem in the metal sulfide-based anode materials. This study developed a strategy to achieve high initial coulombic efficiency and superior capacity retention by interpenetrating binary metal sulfides of SnS and MoS₂ in a conductive carbon matrix. The synergy ascension of electrochemical performances for the metal sulfides is attributed to their mutual impeding effects on coarsening of metal grains and the capsule-shaped coating structure embedded in the carbon sheet architecture. The SnS/MoS₂/C composite was prepared by a simple NaCl template-assisted ball milling method, and showed excellent electrochemical performances in terms of a high initial coulombic efficiency up to 90.2% and highly stable reversibility with a specific capacity of 515.4 mA h g⁻¹ after 300 cycles at 1.0 A g⁻¹. All of these characteristics suggest that the proposed materials are superior among the previously reported metal sulfide-based anode materials for lithium-ion batteries.

Binary metal sulfides of SnS and MoS₂ interpenetrated in carbon sheets achieve high initial coulombic efficiency and superior capacity retention.     

Experimental and theoretical study for CO2 activation and chemical fixation with epoxides

The synthesis of five-membered cyclic carbonates via catalytic cycloaddition reaction of CO₂ with epoxides is considered to be an effective technology for alleviation of the energy crisis and global warming. Various commercial organic bases and ionic salts were used as catalysts, while the relationship of catalytic activity and compound structure has been seldom explored. Herein, a facilely obtained binary catalytic system based on triethylamine/NBu₄Br was developed for CO₂ activation and chemical fixation. The highly efficient catalytic system showed outstanding conversion and above 99% selectivity under metal-free mild reaction conditions (100 °C, 1 atm) in one hour. The detailed process of CO₂ activation and chemical fixation was investigated at the molecular level by a series of experiments and theoretical calculation, which provided a mode for the design and synthesis of a highly efficient catalytic system for conversion of CO₂ under mild conditions.

NEt₃/NBu₄Br works as an excellent metal-free catalyst for CO₂ cycloaddition with epoxides and the detailed process of CO₂ activation by NEt₃ is first studied by theoretical calculation.     

Silica cubosomes templated by a star polymer

The organization of amphiphilic molecules into well-defined geometries and morphologies is an area of fundamental and practical importance. Herein, we report silica cubosomes synthesized by the cooperative self-assembly of the amphiphilic star polymer poly(ethylene glycol)-(polystyrene)₂. The silica cubosomes exhibit a spherical shape and a highly ordered bicontinuous diamond-surface structure. A new synthesis-field diagram was constructed based on the mass ratio of THF, HCl (2 M) and the polymer. Moreover, the mechanism of the formation of silica cubosomes has been revealed. Due to the inorganic framework, the silica cubosomes show enhanced stability and a wide scope of applications.

Silica cubosomes were synthesized using a silica precursor and its formation mechanism was revealed.     

p-Type CuCrO2 particulate films as the hole transporting layer for CH3NH3PbI3 perovskite solar cells

CuCrO₂ with a crystal structure of delafossite is a promising material as a transparent conducting oxide. It shows unique properties, for example, wide band gap, good chemical stability, and p-type carrier transporting character. The oxide layers with delafossite structure have been suggested as hole transporting materials for organic–inorganic CH₃NH₃PbI₃ perovskite solar cells. In this study, we fabricated inverted (p–i–n) type planar perovskite solar cells with CuCrO₂ nanoparticles synthesized by the hydrothermal method and their films were formed by spin-coating without any further heat treatment. The champion device gave a 13.1% of power conversion efficiency and CuCrO₂ based devices show improved stability in ambient air compared with the standard PEDOT:PSS based perovskite solar cells.

CuCrO₂ with a crystal structure of delafossite is a promising material as a transparent conducting oxide.     

Carbon nitride used as a reactive template to prepare mesoporous molybdenum sulfide and nitride

Carbon nitride C₃N₄ has been used as a sacrificial template to prepare inorganic materials with hierarchical pore structure. C₃N₄ impregnated with ammonium heptamolybdate was treated in reactive gas mixtures (H₂S/H₂ or NH₃/H₂). This approach allowed mesoporous molybdenum sulfide and molybdenum nitride materials to be obtained that replicate the morphology of the C₃N₄ template. Advantageous catalytic properties have been demonstrated in the thiophene hydrodesulfurization (HDS) and electrochemical hydrogen evolution reaction (HER). The highest rates in both reactions were observed for partially sulfidized Mo₂N solid.

Carbon nitride C₃N₄ has been used as a sacrificial template to prepare inorganic materials with a hierarchical pore structure.     

Recent advances in the chemistry of 2-chloroquinoline-3-carbaldehyde and related analogs

This review highlights the recently cited research data in the literature on the chemistry of 2-chloroquinoline-3-carbaldehyde and related analogs and their applications over the period from 2013 to 2017. It covers: synthesis of quinoline ring systems and reactions adopted to construct fused or binary quinoline-cord heterocyclic systems. The biological evaluation and the synthetic applications of the target compounds were illustrated.

This review describes the recent publications reported on the chemistry of 2-chloroquinoline-3-carbaldehydes. Heterocyclic quinoline ring systems are binary and fused cycles.     

The physicochemical properties of a room-temperature liquidus binary ionic liquid mixture of [HNMP][CH3SO3]/[Bmim]Cl and its application for fructose conversion to 5-hydroxymethylfurfural

Via heating first and then cooling, binary ionic liquid (IL) mixture of N-methyl-2-pyrrolidonium methylsulfonate ([HNMP][CH₃SO₃]) and 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) could form a liquid at room temperature. The glass-transition temperature (T_g) characterized by DSC depends on its composition with T_g being as low as −63 °C. The physicochemical properties of the binary IL mixtures also vary with the composition. With the increase of the mole fraction of [Bmim]Cl, the hydrogen-bond accepting ability (β) of the binary IL mixture increases, but the hydrogen-bond donating ability (α) deceases. In this binary IL mixture, fructose could be effectively converted into 5-hydroxymethylfurfural (HMF) at room temperature. The HMF yields at a given time are found to be well correlated with the physicochemical properties of the binary mixture, especially the α and β values. Under specified conditions, the present IL mixture as medium for fructose dehydration into HMF is comparable to the medium formed by ILs and alcohol, where the alcohols have negative effect on the HMF formation.

A liquidus mixture of [HNMP][CH₃SO₃]/[Bmim]Cl has been characterized and tried as medium for room-temperature conversion of fructose into HMF.     

Au nanoparticle-decorated TiO2 hollow fibers with enhanced visible-light photocatalytic activity toward dye degradation

TiO₂ hollow fibers (THF) were prepared by a template method using kapok as a biotemplate and subsequently decorated by plasmonic Au nanoparticles using a solution plasma process. The THF exhibited an anatase phase and a hollow structure with a mesoporous wall. Au nanoparticles with a diameter of about 5–10 nm were uniformly distributed on the THF surface. Au nanoparticles-decorated TiO₂ hollow fibers (Au/THF) have enhanced photocatalytic activity toward methylene blue degradation under visible light-emitting diode (Vis-LED) as compared to pristine THF and P25. This could be attributed to combined effects including effective light-harvesting by a hollow structure, large surface area due to a mesoporous wall of THF, and visible-light absorption and efficient charge separation induced by Au nanoparticles. The Au/THF also showed good recyclability and separation ability.

Plasmonic Au nanoparticles-decorated TiO₂ hollow fibers with enhanced visible-light photocatalytic activity have been successfully prepared by a two-step process: (i) template method using kapok and (ii) solution plasma process.     

Polyellisin,a novel polyketide from cultures of the basidiomycete Polyporus ellisii

Polyellisin (1), an unprecedented polyketide possessing a tricyclic system sharing a spiroketal carbon, was isolated from cultures of the basidiomycete Polyporus ellisii. The structure with absolute configuration was elucidated by means of spectroscopic methods and the single crystal X-ray diffraction. Polyellisin showed NO production inhibition with an IC₅₀ value of 17.2 μM.

Polyellisin (1), an unprecedented polyketide possessing a tricyclic system sharing a spiroketal carbon, was isolated from cultures of the basidiomycete Polyporus ellisii.     

A general method for the synthesis of covalent and ionic amine borane complexes containing trinitromethyl fragments

A general approach for the synthesis of covalent and ionic amine borane complexes containing trinitromethyl fragments has been developed through metathesis reactions between amine chloroborane complexes and potassium salt of trinitromethyl (K[C(NO₂)₃]). Five covalent and ionic trinitromethyl amine borane complexes have been synthesized in good yields with high purity and it is found that the ionic complex, [H₂B(NH₃)₂][C(NO₂)₃], might be a promising energetic material on the basis of the investigation of its thermal decomposition behaviour.

A general approach has been developed through which five covalent and ionic amine borane complexes containing trinitromethyl fragments were synthesized.