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The adoption and evolution of water molecules and ions in mixed electrolytes at the surface play vital roles in the physical properties and chemical reactions of SiO2-like corrosion. The effect of salt type and concentration on the structure and dynamics of water molecules and ions at silica surfaces are studied using all-atom molecular dynamics simulations taking the case of the NaCl, MgCl2, and NaCl–MgCl2 aqueous solutions. The ability of ion hydration is in the order of Mg2+ > Na+ > Cl−, being opposite to their hydration Gibbs free energies, which directly influence the weak interaction in the solution and the diffusion rate of the particles. Mg shows stronger destruction to weak interactions than Na does, and ionic hydration of Mg2+ decelerates the self-diffusion coefficient of water molecules significantly due to the enhanced Coulomb effect and the interruption of solution continuity. Meanwhile, the self-diffusion coefficient of particles decreases with the concentration improvement in the single salt solution as increased ionic hydration. In the mixed salt solution, the order of diffusion rate is Cl− > Na+ > Mg2+ as a result of the different confinement effects of the protonated pore. Interestingly, a small amount of Na+ addition can promote the self-diffusion of Mg2+, but a great many of Na+ addition slows the diffusion of Mg2+. This work provides comprehensive insight into the behavior of mixed salt solutions at silica surfaces, shedding light on the practical applications of geological sciences, cultural relics protection, and colloidal sciences. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The NiO foam structures were prepared by heating Ni(NO 3) 2 –PVP aqueous solution. • This foam structures are assembled from NiO nanosheets with exposed {1 1 1} facets. • The 3-coordinated Ni atoms at Ni NiO (1 1 1) surface act as the sensing reactive sites. • They can absorb O 2 molecules, create electrons and catalyze the sensing reaction. • A sensing reaction mechanism is presented at the atomic and molecular level. Abstract The NiO foam structures assembled from NiO nanoflakes with exposed {1 1 1} and {0 2 2} facets were successfully prepared by heating aqueous Ni(NO 3) 2 solution containing polyvinyl pyrrolidone (PVP) at 450–650 °C. The NiO foam structures with exposed {1 1 1} facets obtained at 650 °C show significantly higher response values to ethanol, formaldehyde and triethylamine than NiO particles and NiO foam structures with exposed {0 2 2} facets obtained at 450 and 550 °C. The excellent sensing performances can be ascribed to the exposed Ni NiO (1 1 1) crystal facets terminated with Ni atoms. We consider that the surface 3–coordinated Ni atoms function as the active sites for gas sensing reaction and present a new sensing mechanism. The 3–coordinated unsaturated Ni atoms can absorb O 2 molecules, generate free electrons and catalyze the chemical reaction between O 2 with test gas. The sensing mechanism of the 3–coordinated unsaturated Ni atoms functioning as the reaction active sites can deepen understanding of the sensing and other catalytic reactions and offers a guidance to design sensing and catalytic materials with excellent performances. [ABSTRACT FROM AUTHOR]

Photooxidation under sunlight has potential in organic synthesis, bacterial killing, and organic waste treatment. Photosensitizers (PSs) can play an important role in this process. High 1O2 generation efficiency and excellent photostability under sunlight, as well as easy recyclability are ideal properties for PSs, but are not easy to achieve simultaneously. Herein, a pure organic porous conjugated polymer PS, CPTF, shows great photostability, large specific surface area, and high 1O2 generation efficiency under sunlight for photooxidation. For the oxidation of aromatic aldehyde to aromatic acid, the PS catalyst shows excellent recyclability, and enables solvent‐free reactions in high yields both under direct sunlight and simulated AM 1.5G irradiation. In addition, the successful application of CPTF as an antibacterial agent and organic waste decomposition under simulated AM 1.5G irradiation indicates the potential of CPTF in sunlight‐induced waste water treatment. A sunny outlook: A cross‐linked porous conjugated polymer photosensitizer CPTF is used for sunlight‐induced photooxidation. Under simulated AM 1.5G irradiation, benzaldehyde can be oxidized to benzoic acid easily on a 10 g scale in the presence of CPTF. In addition, CPTF can also be used as photocatalyst for sunlight‐induced organic waste decomposition and an antibacterial agent in water. [ABSTRACT FROM AUTHOR]

NiO octahedrons with capped Cl − ions were synthesized by heating aqueous NiCl 2 solution at 400 °C. The as-synthesized cubic phase NiO octahedrons are enclosed by {111} surfaces. For acetone, formaldehyde, triethylamine and ethanol, the NiO octahedrons show higher responses than NiO particles, and their responses are significantly increased by removing the surface Cl − ions and −OH groups. The S r of the hydrogenated NiO octahedrons is 1.46, 1.50, 2.34 and 1.53 towards 50 ppm of acetone, formaldehyde, triethylamine and ethanol, respectively. The excellent sensing properties are attributed to the increased the quantity of 3-coordinated unsaturated Ni atoms on the Ni-NiO surface through removal of Cl − ions and −OH groups. The 3-coordinated unsaturated Ni atoms are considered to serve as a sensing reaction active site, and a gas sensing reaction mechanism is presented at the atomic and molecule level. The 3-coordinated unsaturated Ni atoms can absorb O 2 molecules, generate free electrons and catalyze the reaction between the absorb O 2 with the detected gas. The sensing mechanism of 3-coordinated unsaturated Ni atoms serving as the reaction active sites will be useful for the understanding of sensing and other catalytic reaction mechanisms as well as the design and fabrication of advanced gas sensing materials and catalysts. [ABSTRACT FROM AUTHOR]

A series of novel 6-(trifluoromethyl)-1,2,3,4-tetrahydropyrimidine-5-carboxylate derivatives were obtained in good yields from ethyl 4,4,4-trifluoro-3-oxobutanoate, urea, and aryl aldehyde via Biginelli multicomponent reaction. All the corresponding products 4a-4p were examined against four human cancer cell lines (A549, HepG2, COLO205 and DU145) and compounds 4e, 4i, and 4 m which showed promising anticancer activity have been identified. [ABSTRACT FROM AUTHOR]

Abstract: Bio‐orthogonal tumor labeling is more effective in delivering imaging agents or drugs to a tumor site than active targeting strategy owing to covalent ligation. However, to date, tumor‐specific imaging through bio‐orthogonal labeling largely relies on body clearance to differentiate target from the intrinsic probe signal owing to the lack of light‐up probes for in vivo bio‐orthogonal labeling. Now the first light‐up probe based on a fluorogen with aggregation‐induced emission for in vivo bio‐orthogonal fluorescence turn‐on tumor labeling is presented. The probe has low background fluorescence in aqueous media, showing negligible non‐specific interaction with normal tissues. Once it reacts with azide groups introduced to tumor cells through metabolic engineering, the probe fluorescence is lightened up very quickly, enabling rapid tumor‐specific imaging. The photosensitizing ability was also used to realize effective image‐guided photodynamic tumor therapy. [ABSTRACT FROM AUTHOR]

Oxidative stress has been associated with diverse diseases, including obesity, cancer and neurodegeneration. In fact, Valeriana jatamansi Jones (valerian) and its extracts possess strong antioxidant activities that extend their application in clinical practice to the treatment of these illnesses, even though the underlying mechanisms are not well understood. Iridoid valepotriate, a characteristic iridoid ester in valerian with poor chemical stability, possesses considerable antioxidant components. The original compounds and their degradation products have been found to exhibit strong antioxidant activities. However, the relationship between their structure and antioxidant effects and the mechanism underlying their oxidation resistance remain unclear. A forced degradation study using three iridoid valepotriates (valtrate, acevaltrate and 1-β acevaltrate) was performed in this work, and the structures of their degradation products were estimated by TLC-MS and LC-MS. Comparison of the antioxidant activities of the iridoid valepotriates before and after forced degradation revealed that degradation reduced the activities of the iridoid valepotriates in free radical scavenging and cytotoxic and cell apoptosis tests. The results suggested that the oxirane nucleus is important for defining the antioxidant profile of iridoid valepotriate. We uncovered possible mechanisms that could explain the antioxidant activities, including the generation of two hydroxyl groups through intramolecular transfer of an H• from an oxirane ring and a reduction in ROS levels through interactions with GABAergic signalling pathways. [ABSTRACT FROM AUTHOR]

Reversible homolytic dissociation of the bis(pyrimidinenorcorrole) σ-dimer was elucidated by means of variable temperature ESR and 1H NMR spectroscopy, mass spectrometry, and optical spectrocopy. Dehydrogenation of the σ-dimer yielded another dimer displaying a singlet-triplet equilibrium in solution, strong NIR absorption (1570 nm), and a narrow electrochemical HOMO-LUMO gap (0.74 V). [ABSTRACT FROM AUTHOR]

A novel approach to enhance the photocurrent and photostability of semiconductor-sensitized photoelectrochemical cells (PECs) with a nonsacrificial electrolyte by grafting the CdS surface with a molecular relay, 4-( N, N-diphenylamino)benzoic acid (DPABA) is reported. Using this modification, the PECs are able to perform overall water splitting instead of only hydrogen generation. The probable reasons for the improvement are that the photogenerated holes in the CdS valence band could be rapidly removed by DPABA, which facilitates charge separation and thus suppresses the photocorrosion process. The use of such a method might further improve the performance of overall water splitting, together with superior light-absorption sensitizers and more suitable molecular relays with better oxygen evolution reaction catalytic properties. [ABSTRACT FROM AUTHOR]

Crystal facet engineering of semiconductors is proven to be an effective strategy to increase photocatalytic performances. However, the mechanism involved in the photocatalysis is not yet known. Here, we found that photocatalytic performances of the Cl − ion capped NiO octahedrons with exposed {1 1 1} facets were activated by treatment of AgNO 3 and NH 3 ·H 2 O solutions. The clean NiO {1 1 1} facets were found to be highly reactivity faces. Based on polar structure of the {1 1 1} surfaces, a charge separation model between polar {1 1 1} surfaces is proposed. The internal electric field created by the spontaneous polarization drives effectively separation of photogenerated electrons and holes. The reduction and oxidation reactions selectively take place on the positive Ni NiO and negative O NiO planes. The good charge separation results in high photocatalytic activity. Our model suggests the polar surface-engineering as a strategy to develop more effective photocatalysts and new type of solar cells, electronic and photoelectric devices. [ABSTRACT FROM AUTHOR]

Arabidopsis cryptochrome 2 (CRY2) is a blue light receptor that mediates light inhibition of hypocotyl elongation and long-day promotion of floral initiation. CRY2 is known to undergo blue light-dependent phosphorylation, which is believed to serve regulatory roles in the function of CRY2. We report here on a biochemical and genetics study of CRY2 phosphorylation. Using mass spectrometry analysis, we identified three serine residues in the CCE domain of CRY2 (S588, S599, and S605) that undergo blue light-dependent phosphorylation in Arabidopsis seedlings. A study of serine-substitution mutations in the CCE domain of CRY2 demonstrates that CRY2 contains two types of phosphorylation in the CCE domain, one in the serine cluster that causes electrophoretic mobility upshift and the other outside the serine cluster that does not seem to cause mobility upshift. We showed that mutations in the serine residues within and outside the serine cluster diminished blue light-dependent CRY2 phosphorylation, degradation, and physiological activities. These results support the hypothesis that blue light-dependent phosphorylation of the CCE domain determines the photosensitivity of Arabidopsis CRY2. [ABSTRACT FROM AUTHOR]

Copper-catalyzed ortho-halogenation of C(sp2)–H bonds directed by a PIP directing group with NXS (X = Cl, Br, I) has been developed. The reaction is scalable and tolerates a broad range of functional groups and heteroarenes, providing an efficient access to halogenated arenes and heteroarenes. [ABSTRACT FROM AUTHOR]

Highlights: [•] The steric hindrance mainly suppressed the reactivities of S-compounds and olefins. [•] H2S inhibition effect was severe on HDS reactivity, thus decreasing the selectivity. [•] The interconversion of Lewis and Brønsted acid sites explained the H2S inhibition. [•] The HYD pathway of the HDS reaction was principally affected. [•] Catalysts with appropriate acidic sites proportion was effective in selective HDS. [ABSTRACT FROM AUTHOR]

Surface plasmon resonances (SPRs) have been found to promote chemical reactions. In most oxidative chemical reactions oxygen molecules participate and understanding of the activation mechanism of oxygen molecules is highly important. For this purpose, we applied surface-enhanced Raman spectroscopy (SERS) to find out the mechanism of SPR-assisted activation of oxygen, by using p-aminothiophenol (PATP), which undergoes a SPR-assisted selective oxidation, as a probe molecule. In this way, SPR has the dual function of activating the chemical reaction and enhancing the Raman signal of surface species. Both experiments and DFT calculations reveal that oxygen molecules were activated by accepting an electron from a metal nanoparticle under the excitation of SPR to form a strongly adsorbed oxygen molecule anion. The anion was then transformed to Au or Ag oxides or hydroxides on the surface to oxidize the surface species, which was also supported by the heating effect of the SPR. This work points to a promising new era of SPR-assisted catalytic reactions. [ABSTRACT FROM AUTHOR]

The knowledge of accurate bond strengths is a fundamental basis for a proper analysis of chemical reaction mechanisms. Quantum chemical calculations at different levels of theory have been used to investigate heterolytic Feâ€'O and Feâ€'S bond energies of paraâ€substituted phenoxydicarbonyl( η5â€cyclopentadienyl) iron [ pâ€Gâ€C6H4O( η5â€C5H5)Fe(CO)2, abbreviated as pâ€Gâ€C6H4OFp ( 1), where G = NO2, CN, COMe, CO2Me, CF3, Br, Cl, F, H, Me, MeO, and NMe2] and paraâ€substituted benzenethiolatodicarbonyl( η5â€cyclopentadienyl) iron [ pâ€Gâ€C6H4S( η5â€C5H5)Fe(CO)2, abbreviated as pâ€Gâ€C6H4SFp ( 2)] complexes. The results show that BP86 and TPSSTPSS can provide the best price/performance ratio and more accurate predictions in the study of Î' Hhet(Feâ€'O)'s and Î' Hhet(Feâ€'S)'s. The excellent linear freeâ€energy relations [ r = 0.99 (g, 1a), 1.00 (g, 2b)] among the Î'Î' Hhet (Feâ€'O)'s and Î'p ka's of Oâ€'H bonds of pâ€Gâ€C6H4OH or Î'Î' Hhet(Feâ€S)'s and Î'p ka's of Sâ€'H bonds of pâ€Gâ€C6H4SH imply that the governing structural factors for these bond scissions are similar. And the linear correlations [ r = âˆ'0.99 (g, 1g), âˆ'0.98 (g, 2h)] among the Î'Î' Hhet (Feâ€O)'s or Î'Î' Hhet(Feâ€S)'s and the substituent σpâˆ' constants show that these correlations are in accordance with Hammett linear freeâ€energy relationships. The polar effects of these substituents and the basis set effects influence the accuracy of Î' Hhet(Feâ€'O)'s or Î' Hhet(Feâ€'S)'s. Î'Î' Hhet(Feâ€'O)'s(g) ( 1) and Î'Î' Hhet(Feâ€'S)'s(g)( 2) follow the Captoâ€dative principle. The substituent effects on the Feâ€'O bonds are much stronger than those on the less polar Feâ€'S bonds. Insight from this work may help the design of more effective catalytic processes. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Isostructural heterometallic diruthenium carbonates KM(H2O)6[M(H2O)2Ru2(CO3)4Cl2]·4H2O [M = Zn (1) and Mn (2)] were synthesized from the reaction of the precursors [Ru2(CO3)4Cl2]5− and transitional metal ions in aqueous solution. Complexes 1 and 2 show layered structures in which Ru2(ii,iii) units are linked by four octahedral environment M(H2O)22+ ions in a cross fashion and vice versa giving a negative bimetallic square grid layer {M(H2O)2Ru2(CO3)4Cl2}n3n−. M(H2O)62+ ions, linked by K+ forming zigzag chain {KM(H2O)6}n3+, are located in the void spaces between the layers. The adjacent bimetallic carbonate layers are connected with K–O and K–Cl bonds, and hydrogen bonding, forming a supramolecular 3D framework structure. Their magnetic properties were characterized in detail, and intralayer ferromagnetic coupling between the Ru2 dimer and Mn2+ ion, as well as long-range ordering (Tc = 5.2 K) coexistence of domain movement behavior were observed for complex 2. [ABSTRACT FROM AUTHOR]

Four new inorganic supramolecular complexes, [Hg4P2][ZrCl6] ( 1), [Hg4As2][ZrCl6] ( 2), [Hg4P2][HfCl6] ( 3), and [Hg4As2][HfCl6] ( 4), have been prepared by moderate-temperature solid-state reactions. All compounds crystallize in the space group Pbca of the orthorhombic system with Z = 8. Their structures are built up of mercury pnictide cationic hosts and distorted octahedral [MCl6]2- (M = Zr, Hf) guests. The isolated octahedral guests consist of tetravalent Zr4+ and Hf4+ cations coordinated by chlorine atoms and are embedded in the infinite channels formed by the host framework. Their optical properties were investigated in terms of their diffuse reflectance and FTIR spectra. The electronic band structures along with densities of states (DOS) calculated by DFT indicate that all of the title compounds are semiconductors with direct band gaps, and their optical absorptions mainly originate from charge transitions from Cl 3p and P 3p/As 4p states to Hg 6s, Hg 5p, and Zr 4d/Hf 5d states. Optical dielectric constant calculations show that 1- 4 possess dielectric anisotropy, which is consistent with their structural studies. [ABSTRACT FROM AUTHOR]

A new Co-based 3D framework has been constructed from an unprecedented 1D alternate Co5 chain and discrete linear Co3 unit as two distinct secondary building units, which exhibits slow magnetic relaxation behavior. [ABSTRACT FROM AUTHOR]

Abstract: In this work, the composites of LiBH4 and AlF3 were prepared and their hydrogen storage properties were investigated. The AlF3 addition to LiBH4 resulted in significant decreases in dehydrogenation temperature. All the xLiBH4 +AlF3 (x =1, 2, 3, 5) composites started to release hydrogen from about 100°C. The dehydrogenation of the composites was accomplished through several steps, depending on the molar ratio of LiBH4 to AlF3. A new phase Li3AlF6 was formed during the first dehydrogenation step, which further reacted with LiBH4. AlB2 was formed only at temperatures higher than 300°C. Li2B12H12 was detected as an intermediate. The dehydrogenation reactions have significantly reduced and thus favorable enthalpy changes. However, the reversibility of the composites needs to be improved. [Copyright &y& Elsevier]

Abstract: In this paper, two types of salicylate Cr(III) complexes [Cr(SA)2(en)]TBA·H2O (I) and [Cr(SA)(en)2]Br·H2O (II) have been synthesized (TBA=Tetrabutylammonium, SA=salicylate, en=ethylenediamine) and determined by X-ray crystallography. Then competition reaction with ethylenediamine-N,N,N′,N′-tetraacetic acid (EDTA) or apoovotransferrin (apoOTf) was monitored by UV–Visible and fluorescence spectra at 37°C. It indicated that decomposition rate of k (I) is smaller than k (II). In the reaction with apoOTf, the releasing salicylate ligands will further be combined to OTf along with the serious fluorescence quenching of salicylate. [Copyright &y& Elsevier]

Abstract: Uniform spherical flowerlike SnO2 architectures with the diameters of 1.7–2.0μm were synthesized by a hydrothermal reaction of SnCl4 with NaOH and H2O in the presence of polyvinylpyrrolidone (PVP). These flowerlike architectures are assembled from submicron rods with the diameters of 300–600nm. The constituent submicron rods are single crystalline SnO2 with the tetragonal structure, and grow along the direction perpendicular to (101) facet. The spherical flowerlike architectures constructed with SnO2 submicron rods are formed via the oriented attachment process. The response performance of the sensors based on the SnO2 spherical flowerlike architectures toward ethanol and triethylamine is better than that of SnO2 powders and can be further enhanced by improving their crystallinity. The sensor response is 3.65 and 2.97 when the concentration of ethanol and triethylamine is 105 and 45ppm, respectively. [Copyright &y& Elsevier]

Abstract: A series of four m-ferrocenylbenzoate [m-ferrocenylbenzoate = Na(m-OOCH4C6Fc), Fc = (η 5-C5H5)Fe(η 5-C5H4)] copper(II) complexes Cu2(μ 2-OOCH4C6Fc)4(CH3OH)2 (1), Cu(η 2-OOCH4C6Fc)2(2,2′-bpy) (2), Cu(η 2-OOCH4C6Fc)2(1,10-phen) (3) and [Cu(η 2-OOCH4C6Fc)2(4,4′-bpy)] n (4) (bpy = bipyridine, 1,10-phen = 1,10-phenanthroline) have been synthesized by reactions of Cu(CH3COO)2·H2O with Na(m-OOCH4C6Fc) and three types of N-donor ligands, respectively. X-ray diffraction analysis reveals that 1 shows a dimeric structure with a Cu⋯Cu distance of 2.5872(16) Å. 2 and 3 exhibit a mononuclear structure. The adjacent mononuclear molecules are packed into a one-dimensional (1D) chain through the π–π interactions between the bpy rings in 2 or phen rings in 3. 4 displays a 1D zigzag chain structure. In 1, the m-OOCH4C6Fc anion adopts the bidentate-bridging coordination mode, whereas it adopts the bidentate-chelating coordination mode in 2–4. Magnetic study indicates that an antiferromagnetic interaction between the CuII ions exists in 1. [Copyright &y& Elsevier]

Abstract: Hollow inorganic–organic hybrid microspheres, such as silica, titania, and zirconia, with interior poly(methacrylic acid) (PMAA) functionalized shell were synthesized by a general method containing a two-stage reaction. The hollow inorganic shell-layer with interior polymeric component was formed over the PMAA template during the second-stage controlled hydrolysis of inorganic precursors together with disintegration of PMAA cores and adhering to the interior wall of the silica during the drying process due to the capillary force as well as the competitive hydrogen bond interaction. In this process, PMAA microspheres were prepared by distillation precipitation polymerization of methacrylic acid (MAA) in acetonitrile as the first-stage reaction. The present work elaborately investigated the effects of the reaction conditions, including the amount of the tetraethyl orthosilicate (TEOS) precursors and the amount of ammonium hydroxide catalyst on the morphology and structure of the resultant hollow composite microspheres, which were characterized by transmission electron microscopy (TEM), Fourier-transform infrared spectra (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption. [Copyright &y& Elsevier]

Abstract: NO reduction by CO reaction was comparatively studied over microwave plasma pretreated CuO/TiO2 catalysts employing transmission electron microscopy (TEM), hydrogen temperature programmed reduction (H2-TPR), and in situ Fourier-transform infrared spectroscopy (in situ FTIR). The catalytic performances indicated that a remarkable improvement in activity and selectivity was achieved after microwave plasma pretreatment, which was dependent on the microwave plasma pretreatment time. The results also suggested that a high active oxygen species (O*) was formed on the surface of plasma pretreated CuO/TiO2 catalysts, which led to the easy oxidation of NO to NO2 at low temperature even without introducing any additional O2 gas into the reaction system. Therefore, these high active oxygen species (O*) should play an important role for the exaltation of the catalytic performances of the catalysts. [Copyright &y& Elsevier]

Abstract: NiO crystallites based nanowires with different aspect ratios have been synthesized by a hydrothermal reaction of NiCl2 with NaC2O4 and H2O in the presence of ethylene glycol (EG) and subsequent annealing at 400°C in air. Control over the aspect ratios of NiC2O4·2H2O precursor nanowires in the range of 11–1050 was achieved by adjusting the hydrothermal reaction temperature and time. The formation of the NiC2O4·2H2O nanowires results from the selective adsorption of EG molecules on , , (010) and prismatic faces of NiC2O4·2H2O with a monoclinic structure. The gas-sensing performance of the as-prepared NiO nanowires with different aspect ratios was investigated towards toluene, ethanol, acetone, triethylamine and methanol. It was found that the gas-sensing performance was improved with an increase on the aspect ratios of NiO nanowires. [Copyright &y& Elsevier]

Abstract: An efficient synthesis of 1,3,5-trisubstituted benzenes via a sequential Pd-mediated carbon–sulfur, carbon–nitrogen, and carbon–carbon bond formation reactions is reported. Selective amidation and sulfonamidation reactions are accomplished via Pd-catalyzed reactions between aryl chlorides and an acetamide or a methanesulfonamide. [Copyright &y& Elsevier]

Abstract: The mixtures of LiBH4 with halides of Ce or La in a molar ratio of 3:1 were investigated to explore their hydrogen storage properties. The ball milling of LiBH4 with chloride of Ce or La yielded Ce(BH4)3 and La(BH4)3, while fluoride of Ce or La did not react with LiBH4 during extended ball milling at room temperature. The dehydrogenation temperatures of the ball-milled mixtures were reduced to 220–320°C, which were much lower than that of pure LiBH4. The diborane emission during hydrogen release was observed at a low level. The dehydrogenation temperature is found to be affected by the composition of rare earth halides, but less influenced by ball milling time. The endothermic dehydrogenation reactions produced lithium halides, hydrides and borides of the corresponding rare earth element. Moreover, the LiBH4 +1/3(Ce, La)(Cl, F)3 showed partial reversibility through the formation of an unknown borohydride, allowing for a potential hydrogen storage system. [ABSTRACT FROM AUTHOR]

Abstract: The fuel efficiency of borohydride electro-oxidation on carbon-supported Au and Ag electrodes was found to be highly dependent on the concentration ratio of [OH−]/[BH4 −] in the solution. Near-8e reactions occurred when [OH−]/[BH4 −]≥5. However when [OH−]/[BH4 −] was smaller than 5, hydrogen gas was evolved and the fuel efficiency was reduced. Only 3e reaction stoichiometry was obtained at [OH−]/[BH4 −]=1. Detailed cyclic voltammetry (CV) studies revealed that both the Au/C and Ag/C showed different anodic waves in varied NaOH–NaBH4 solutions. The CV analysis results suggest that BH3OH−, an intermediate possibly produced by homogeneous hydrolysis, is responsible for the electrochemical reaction at [OH−]/[BH4 −]=1. Comparison of CV voltammograms in borohydride solutions with that in the H2-bubbled NaOH solution suggests that borohydride electro-oxidation on Au or Ag electrode is through direct BH4 − oxidation rather than through a hydrogen ionization mechanism. It is concluded that there exists an inherent competition between two oxidizing species of OH− and H2O during borohydride electro-oxidation, that is, if accessible OH− ions are not sufficient for each BH4 − to accomplish the 8e electro-oxidation, part of BH4 − will react simultaneously with H2O to generate hydrogen. [Copyright &y& Elsevier]

Abstract: In situ FT-IR was employed to investigate CO or/and NO interaction with CuO supported on Ce0.67Zr0.33O2 (hereafter denoted as CZ) catalysts. The physicochemical properties of CuO–CZ were also studied by combination of XRD, TPR and NO+CO activity tests. The results indicated that the dispersed CuO species were the main active components for this reaction. The catalysts showed different activities and selectivities at low and high temperatures, which should be resulted from the reduction of dispersed copper oxide species. This reaction went through different mechanisms at low and high temperatures due to the change of active species. FT-IR results suggested: (1) CO was activated by oxygen originating from CZ support, which led to surface carbonates formation, and partial dispersed CuO was reduced to Cu+ species above 150°C; (2) NO interacted with the dispersed CuO and formed several types of nitrite/nitrate species, whereas crystalline CuO made little contribution to the formation of new NO adsorbates; (3) NO was preferentially adsorbed on CuO–CZ catalysts compared with CO in the reactants mixture. These adsorbed nitrite/nitrate species exhibited different thermal stability and reacted with CO at 250°C. As a result, a possible mechanism was tentatively proposed to approach NO reduction by CO over CuO–CZ catalyst. [Copyright &y& Elsevier]

IFN-γ treatment of cells leads to tyrosine phosphorylation of signal transducer and activator of transcription (STAT) 1 followed by dimerization through a reciprocal Src homology 2-phosphotyrosine interaction near the -COOH end of each monomer, forming a parallel structure that accumulates in the nucleus to drive transcription. Prompt dephosphorylation and return to the cytoplasm completes the activation-inactivation cycle. Nonphosphorylated STATs dimerize, and a previously described interlace between N-terminal domain (ND) dimers has been implicated in this dimerization. A new crystal structure of non phosphorylated STAT1 containing the ND dimer has two possible configurations for the body of STAT1, one of which is antiparallel. In this antiparallel structure, the Src homology 2 domains are at opposite ends of the dimer, with the coiled:coil domain of one monomer interacting reciprocally with the DNA-binding domain of its partner. Here, we find that mutations in either the coiled:coil/DNA-binding domain interlace or the ND dimer interlace block dimerization of nonphosphorylated molecules and cause a resistance to dephosphorylation in vivo and resistance to a tyrosine phosphatase in vitro. We conclude that a parallel STATI phosphodimer not bound to DNA most likely undergoes a conformational rearrangement (parallel to antiparallel) to present the phosphotyrosine efficiently for dephosphorylation. [ABSTRACT FROM AUTHOR]

Reaction of α-diimine-stabilized “digallane” [Ga2L2] with phenazine (Phz) leads to gallium complexes in which Phz and α-diimine show different reduced forms, demonstrating their noninnocence and diverse coordination modes. [ABSTRACT FROM AUTHOR]

Abstract: [{MnIII(OH)(H2O)}3SiW9O34]4− 1a, has been isolated from the reaction of Na9[β-SiW9O34H]·23H2O and [Mn3O(O2CMe)6(HIm)3](O2CMe) (Im=imidazole C3H4N2) in aqueous solution. The trimetal-substituted polyoxometalate (TMSP) 1 has been fully characterized by single-crystal X-ray diffraction, elemental analysis, thermogravimetric analysis, and infrared spectroscopy. This monomeric anion is composed of one trilacunary Keggin fragment A-α-SiW9O34 and three manganese ions encapsulated resulting in a triangular {Mn(OH)}3 6+ ring core. Experimental structural and magnetism aspects of the material are reported and discussed. [Copyright &y& Elsevier]

A colorimetric and ratiometric fluorescent chemosensor for F−has been prepared, which is based on combination of desilylation reaction and excited-state proton transfer from the desilylation product to F−. The sensor exhibits rapid response, excellent selectivity and sensitivity to F−. [ABSTRACT FROM AUTHOR]

Esters can be successfully reduced to the corresponding alcohols with potassium borohydride/lithium chloride under microwave irradiation without solvent. The reactions are generally completed in 2–8 minutes, with the yields varying from 55% to 95%. [ABSTRACT FROM AUTHOR]

Dominoreaktionen. In der Zuschrift auf S. 3788 ff. präsentieren M.‐H. Zeng et al. die Synthese eines freien Kohlenstoffradikals durch die Dominoreaktion eines primären Amins mit FeCl3⋅6 H2O in Methanol unter Solvothermalbedingungen. [ABSTRACT FROM AUTHOR]

The 21-(dimethylamino)methyl N-confused porphyrin derivatives were synthesised by the Mannich reaction of dimethylmethyleneimmonium chloride and N-confused porphyrin. The reaction took place regioselectively in the inner carbon of the inverted pyrrole of N-confused porphyrins. [ABSTRACT FROM AUTHOR]

A stable CuZnO/SiO 2 methanol synthesis catalyst with narrow particle size distribution was successfully prepared through a facile method. • A facile method is proposed to prepare well dispersed CuZnO/SiO 2 catalysis. • Narrower dispersion of active metal particle size are more favorable to improve catalytic stability. • Existence of bulk CuO particle would accelerate particle growth leading to catalyst deactivation. • The Ostwald ripening mechanism is response for particle growth in this type of catalyst. The metal particle size distribution of a catalyst can affect the rate of deactivation in many chemical reaction. This work developed a facile method to prepare a well dispersed CuZnO/SiO 2 catalyst via rotary evaporation assisted deposition-precipitation method (RE-CZS). By comparison, conventional deposition-precipitation method and ultrasound assisted deposition-precipitation method were applied to synthesize other catalysts (Im-CZS and Ul-CZS), in order to clarify the influence of Cu particle size distribution of the catalyst on catalytic stability of methanol synthesis via CO 2 hydrogenation. RE-CZS catalyst possessed the narrowest Cu particle distribution (ca. 4.9–9.1 nm) and thus exhibited the best catalytic stability because of the least Cu particle growth. Im-CZS catalyst showed the broadest Cu particle distribution (ca. 5.3–28.7 nm) and suffered from the most serious particle growth resulting in the least catalytic stability. The Cu particle distribution and the related catalytic stability of the Ul-CZS catalyst lied between RE-CZS catalyst and Im-CZS catalyst. The origin of the tremendous effect of the Cu particle size distribution on the catalytic stability was studied via XRD, N 2 adsorption/desorption, N 2 O chemisorption, ICP-AES, XPS, TEM and temperature-programmed techniques, which suggested that catalyst deactivation was mainly attributed to the growth of Cu particles originating from Ostwald ripening effect. [ABSTRACT FROM AUTHOR]

An abstract of the article "Asymmetric Hetero-Diels-Alder Reaction of Diazenes Catalyzed by Chiral Silver Phosphate: Water Participates in the Catalysis and Stereocontrol" by Bin Liu and colleagues is presented.

The transformation is suggested to proceed via an iminium ion, generated from TMEDA, which is sequentially attacked by indole (I) and water followed by hydrolyzation to form an intermediate aldehyde. [ABSTRACT FROM AUTHOR]

Abstract: In this work, we explored the possibility of NaBH4 synthesis when Mg reacted with hydrous sodium borates under hydrogen. It was found that Mg could react with the water in molten hydrous borates to form MgO and release hydrogen, which can be used for NaBH4 synthesis. Then remained Mg would react with formed anhydrous borate to form NaBH4. NaBO2 conversion rate was decreased with increase of the crystalline water content in the hydrous sodium borates. Based on experimental results, a mechanism of NaBH4 formation when Mg reacted with hydrous sodium borates was suggested. [Copyright &y& Elsevier]

One-dimensional (1D) magnetic Fe 3 O 4 /P(MBAAm- co -MAA) nanochains were prepared by distillation–precipitation polymerization of MBAAm and MAA in the presence of Fe 3 O 4 nanoparticles as building blocks under a magnetic heating stirrer, which played two critical roles: serving as magnetic field to induce the self-assembly of Fe 3 O 4 nanoparticles into 1D nanochains and providing thermal energy to induce the polymerization of MAA and MBAAm on the surface of the Fe 3 O 4 nanoparticles. The thickness of the P(MBAAm- co -MAA) layer can be easily tuned by adjusting the successive polymerization steps. The polymer layer that contained carboxyl groups was used as stabilizers for loading Ag nanoparticles and the reaction locus for deposition of outer silica layer via a sol–gel method in presence of C 18 TMS as the pore directing agent for tri-layer nanochains. The corresponding hollow mesoporous silica nanochains with movable maghemite cores (γ-Fe 2 O 3 @ m SiO 2 ) were produced after removal of the polymer mid-layer and the alkyl groups of the pore directing agent via calcination of the tri-layer nanochains at high temperature. The Fe 3 O 4 /P(MBAAm- co -MAA)/Ag nanochains exhibited a highly catalytic efficiency and well reusable property toward the reduction of nitrophenol. Furthermore, the γ-Fe 2 O 3 @ m SiO 2 nanochains possessed hollow mesoporous structure and high specific surface area (197.2 m 2 g −1 ) were used as a drug carrier, which displayed a controlled release property. [ABSTRACT FROM AUTHOR]

Abstract: The effect of Al2O3 content on ignition temperature and combustion temperature, the phase composition, the density of the products and the grain size of TiC was investigated by self-propagating high-temperature synthesis reaction of Al2O3–Ti–C system. The results show ignition temperature increases and combustion temperature decreases with the increasing of Al2O3 content; the density of the products varies with Al2O3 content, TiC and Al2O3 are the two stable phases after SHS, TiC particle size decreases with the increasing of Al2O3 content, furthermore, the fracture type of the sintered specimens is a nearly completely intergranular mode. [Copyright &y& Elsevier]

Abstract: The traditional hydrothermal method for synthesis of H2Ti3O7 nanotubes was modified, and the total hydrothermal reaction time of forming a matured network of H2Ti3O7 nanotubes was successfully decreased by 50%. The effect of hydrothermal reaction time on morphology and photocatalytic activity of H2Ti3O7 nanotubes was investigated and discussed. Various morphologies can be observed in the as-prepared samples with different hydrothermal reaction times. The photocatalytic activity of the as-prepared samples was evaluated for degradation of methyl orange (MO) under simulated solar irradiation. It was found that the sample treated in the hydrothermal condition for 36h with a matured network of H2Ti3O7 nanotubes showed excellent photocatalytic activity. The photocatalytic activity results were discussed in detail. The stronger absorption in the ultraviolet (UV) range, the increasing crystallization of H2Ti3O7 phase, and larger surface area and pore volume contributed to the enhancement of photocatalytic activity of the as-prepared samples. [Copyright &y& Elsevier]

Abstract: 2-(4-Bromophenyl)-3-(4-diphenylaminophenyl)acrylonitrile was prepared by the base catalysed condensation of 4-diphenylaminobenzaldehyde and 2-(4-bromophenyl)acetonitrile. A series of α,β-diarylacrylonitrile derivatives containing both a biphenyl group and a triphenylamine unit were synthesized from 2-(4-bromophenyl)-3-(4-diphenylaminophenyl)acrylonitrile and boronic acids via a Suzuki reaction. The structures of these compounds were characterized using FTIR, 1H NMR, 13C NMR, MS and elemental analysis. The UV–vis absorption and photoluminescent spectra of these derivatives were investigated. These compounds emit green fluorescence with maximum emission peaks of 500–550 nm in CH2Cl2 solution and in the solid state under UV irradiation. Analysis revealed good thermal stability with a decomposition temperature ranging from 279–386 °C. [ABSTRACT FROM AUTHOR]

The undecatungstochromoindic heteropoly acid (HPA) H6[In(H2O)CrW11O39]·11H2O was synthesized for the first time by the stepwise acidification and the stepwise addition of solutions of the component elements, as well as the ion exchanging cooling method. The optimal proportion of the component compounds and the pH of the synthesis reaction are given. The product was characterized by means of inductively coupled plasma (ICP), IR, UV, X-ray diffraction (XRD) and thermal analysis. The IR, UV and XRD indicate that H6[In(H2O)CrW11O39]·11H2O possesses the Keggin structure. The results of AC impedance measurement show that its proton conductivity is 1.15×10−3 S cm−1 at room temperature (16 °C). [Copyright &y& Elsevier]

We demonstrated a new approach to increasing response of Fe 2 O 3 nanoparticles and sea urchin-like nanostructures towards methanol, ethanol, formaldehyde, acetone, triethlamine and n-Butylamine by increasing number of surface Fe atoms having dangling bonds through hydrogenation. The surface Fe atoms having dangling bonds are believed to serve as the reactive atoms for sensing reaction, thus, a gas sensing mechanism at atomic and molecular level is presented for the first time. The surface unsaturated active Fe atoms can adsorb oxygen molecules, produce electrons and catalyze the chemical reaction of the adsorbed oxygen with target gas. Hydrogenation may be a universal approach to increasing gas sensing performances of metal oxides. The gas sensing mechanism can deepen comprehending electron transfer during the gas sensing process and offer guidance to design the gas sensing materials with higher performances. • Hydrogenation is successfully used to improve the sensitivity of α-Fe 2 O 3 gas sensors. • Density of unsaturated Fe atoms at the surface is increased by hydrogenation. • The unsaturated Fe atoms are regarded to act as an active site for sensing reaction. • They generate free electrons, adsorb oxygen and catalyze the gas sensing reaction. • Hydrogenation may be used to improve gas sensing properties of other metal oxides. [ABSTRACT FROM AUTHOR]

Recent applications of photoelectrochemistry at the semiconductor/liquid interface provide a renewable route of mimicking natural photosynthesis and yielding chemicals from sunlight, water, and air. Nanowires, defined as one-dimensional nanostructures, exhibit multiple unique features for photoelectrochemical applications and promise better performance as compared to their bulk counterparts. This article reviews the use of semiconductor nanowires in photoelectrochemistry. After introducing fundamental concepts essential to understanding nanowires and photoelectrochemistry, the review considers answers to the following questions: (1) How can we interface semiconductor nanowires with other building blocks for enhanced photoelectrochemical responses? (2) How are nanowires utilized for photoelectrochemical half reactions? (3) What are the techniques that allow us to obtain fundamental insights of photoelectrochemistry at single-nanowire level? (4) What are the design strategies for an integrated nanosystem that mimics a closed cycle in artificial photosynthesis? This framework should help readers evaluate the salient features of nanowires for photoelectrochemical applications, promoting the sustainable development of solar-powered chemical plants that will benefit our society in the long run. [ABSTRACT FROM AUTHOR]

Graphical abstract Ni x Cu 1- x Al 2 O 4 spinel solution suppresses carbon deposition during the chemical looping oxidation of CH 4 by Ni-Cu-Al 2 O 3 oxygen carriers. The Ni-Cu-Al 2 O 3 oxygen carriers also contain highly active redox-active lattice oxygen compared to a single metal oxide (CuO or NiO) supported on Al 2 O 3. Highlights • Ni-Cu-Al 2 O 3 oxygen carriers with stable performance over 100 redox cycles. • Fully characterized phase interactions in Ni-Cu-Al 2 O 3 oxygen carriers. • CuO-NiO interaction promotes lattice oxygen activity. • Ni 1- x Cu x Al 2 O 4 spinel solid solution is resistant against carbon deposition. Abstract Chemical looping processes present great potentials to achieve carbon capture and fuel conversion with high thermodynamic efficiencies. Well-known applications of chemical looping include combustion and methane reforming, where phase interactions in oxygen carriers play important roles in determining the process performance. In this study, we systematically investigate the interactions between various phases in Ni-Cu-Al 2 O 3 mixed oxides oxygen carriers, which were prepared from layered double hydroxides precursors, synthesized hydrothermally using urea and metal nitrates. It appears that the addition of 32–45 wt% Al 2 O 3 was sufficient to prevent sintering effects over 100 redox cycles at 800 °C, 1 atm, using methane as the fuel. The oxide phases and their compositions were determined using a set of complementary analytical techniques, allowing us to establish relationships between (i) the compositions of the mixed oxides, (ii) the chemical activity of the various types of lattice oxygen present and (iii) the distributions of gaseous products of chemical looping methane oxidation. We found that the mutual doping between NiO and CuO leads to enhanced lattice oxygen activities, whilst the solid solution of NiAl 2 O 4 and CuAl 2 O 4 leads to reduced lattice oxygen activity in the spinel phase, which also turns out to be particularly resistant to carbon deposition. The generality of the composition – activity - performance relationship is demonstrated by the successful prediction of the product distributions of methane oxidation based on solely the elemental compositions of the oxygen carriers. These findings enable the rational formulation of Ni-Cu-Al 2 O 3 oxygen carriers for methane conversion with precise control of product selectivity. [ABSTRACT FROM AUTHOR]

Highlights • Sensitivity of {104} faced α-Fe 2 O 3 nanosheet is signally enhanced by hydrogenation. • Density of the unsaturated Fe atoms on (104) surface is increased by hydrogenation. • The surface unsaturated Fe atoms are regarded to act as a sensing reactive site. • They adsorb oxygen, generate free electrons and catalyze the sensing reaction. • Property of other sensing materials and catalysts may be improved by hydrogenation. Abstract The response of the gas sensors based on α-Fe 2 O 3 nanosheets with exposed {104} facets towards C 2 H 5 OH, CH 3 COCH 3 and N(C 2 H 5) 3 vapors is effectively increased by increasing density of the 1, 2, 3, 4 and 5 coordinated Fe atoms on the Fe-α-Fe 2 O 3 (104) surface through hydrogenation. The 1, 2, 3, 4 and 5 coordinated Fe atoms with dangling bonds were considered to act as an active site for sensing reaction, and a sensing reaction molecule mechanism is presented. The 1, 2, 3, 4 and 5 coordinated unsaturated Fe atoms not only can adsorb oxygen molecules, generate free electrons, but also catalyze the sensing reaction of the test gas with chemisorbed oxygen. The hydrogenation activating surface engineering may be an effective strategy to improve gas sensing and catalytic properties of metal oxides. [ABSTRACT FROM AUTHOR]

The catalytic cracking upgrading reactions over HZSM-5 of different model compounds of bio-oil have been studied with a self-designed fluid catalytic cracking (FCC) equipment. Typical bio-oil model compounds, such as acetic acid, guaiacol, n-heptane, acetol and ethyl acetate, were chosen to study the products distribution, reaction pathway and deactivation of catalysts. The results showed: C 6 –C 8 aromatic hydrocarbons, C 2 –C 4 olefins, C 1 –C 5 alkanes, CO and CO 2 were the main products, and the selectivity of olefins was: ethylene > propylene > butylene. Catalyst characterization methods, such as FI-IR, TG-TPO and Raman, were used to study the deactivation mechanism of catalysts. According to the catalyst characterization results, a catalyst deactivation mechanism was proposed as follows: Firstly, the precursor which consisted of a large number of long chain saturated aliphatic hydrocarbons and a small amount C C of aromatics formed on the catalyst surface. Then the active sites of catalysts had been covered, the coke type changed from thermal coke to catalytic coke and gradually blocked the channels of the molecular sieve, which accelerated the deactivation of catalyst. [ABSTRACT FROM AUTHOR]