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To investigate the effect of metal ions on the assembly of complexes derived from a semirigid tripodal carboxylic acid, 5-(4′-carboxylphenoxy) isophthalic acid (H3L), and two rigid chelating terminal N-donor ligands, dipyrazino[2,3-d:2′3′-f]quinoxaline (dpq) and dipyrido[3,2-a:2′,3′-c]phenazine (dppz), seven 0D → 3D complexes, [Cu(HL)(dpq)(H2O)2] (1), {[Co(HL)(dpq)(H2O)]·H2O}n (2), {[Ni3(L)2(dpq)3(H2O)4]·4H2O}n (3), {[Zn(HL)(dpq)(H2O)]·H2O}n (4), {[Cu2(L)(dppz)]·H2O}n (5), {[Co(HL)(dppz)]·H2O}n (6) and {[Ni3(L)2(dppz)3(H2O)3]}n (7), have been hydrothermally synthesized and structurally characterized by IR, TG and X-ray single-crystal diffraction analyses. Complex 1 is a 0D complex processing an unusual μ1-HL2− anion. Complex 2 features a 1D single chain based on Co(II) ions with a 6-coordinated mode. Complex 3 is the first (2,3,4)-connected 3D dpq-based framework derived from single/bimetallic mixed nodes with {83}2{84·122}{8} topology. Complex 4 is a 1D structure based on Zn(II) ions with a 5-coordinated mode. Complex 5 can be described as a 2D (6,3)-connected structure based on carboxyl-bridged Cu4 cores. Complex 6 is a 1D double chain derived from bimetallic nodes. Complex 7 exhibits a 2D double layer with (2,2,3,3,4)-connected nodes. The structural details of 1–7 were discussed. The solid-state luminescence properties of 1–7 and electrochemical properties of 1–3 have been investigated. The luminescence investigations show that 4 is an effective fluorescence probe for environmentally relevant Fe3+ ions. The electrochemical properties of a carbon paste electrode modified by the complexes 1–3 (1-CPE, 2-CPE and 3-CPE) were studied. 1-CPE has good electrocatalytic activity toward the reduction of nitrite, bromate and hydrogen peroxide in solution.

The clinical treatment of chronic postoperative pain (CPSP) remains challenging. The side effects of chronic morphine treatment limit its clinical application. MEL-0614, a novel endomorphin analogue that is highly selective and agonistic for μ opioid receptor (MOR), produces a more powerful analgesic effect than that of morphine. In this study, we explored the difference in antinociceptive tolerance and related mechanisms between MEL-0614 and morphine in CPSP induced in a skin/muscle incision and retraction (SMIR) mice model. We found that acute administration of MEL-0614 (1, 3, 5, and 10 nmol, i.t.) produced a dose-dependent analgesic effect that was superior to that of morphine in the SMIR mice model. Long-term MEL-0614 treatment (10 nmol, i.t.) did not induce tolerance compared with morphine. Notably, tolerance induced by morphine could be greatly prevented and/or inhibited via cross-administration or coadministration between MEL-0614 and morphine. In addition, MEL-0614 accelerated the recovery of postoperative pain, whereas morphine aggravated postoperative pain and prolonged its recovery time regardless of preoperative or postoperative treatment. In addition, MEL-0614 did not activate microglia and the P2X7R signaling pathway and showed reduced expression iba1 and P2X7R compared with that observed after morphine administration. Release of inflammatory factors was induced by continued administration of morphine during SMIR surgery, but MEL-0614 did not promote the activation of inflammatory factors. Our results showed that MEL-0614 has superior analgesic effects in CPSP and leads to tolerance to a lesser degree than morphine. Further, MEL-0614 may be used as a promising treatment option for the long-term treatment in CPSP.

Emulsions are traditionally prepared by batched emulsifying an oil phase and aqueous phase with a magnetic/mechanical stirrer, homogenizer, or ultrasonic machine, etc. Herein, high internal phase emulsions (HIPEs) produced with a miniature twin screw extruder were first investigated. Adding an oil phase (the mixture of styrene, divinylbenzene, and span 80) and aqueous phase to the inlet of a miniature twin screw extruder, a series of white and viscous HIPEs were obtained at the outlet of the extruder. With the screw rotation speed and the surfactant content varied respectively in the ranges of 50-200 rpm and 5-20%, a series of HIPEs having uniform droplet size were produced. Polymerizing these HIPEs caused a series of polymerized HIPES, which have a well-defined open-cell structure. The method developed herein shows that it is possible to prepare emulsions with oil and water by twin screw extrusion. Also, it may also cause a continuous preparation of HIPEs when the miniature twin screw extruder was replaced by an industrial extruder.

A general method for site-selective difluoroalkylation of alkyl carboxylic redox esters with difluoroenoxysilanes through photoredox-catalyzed decarboxylative reaction has been developed. The reaction can also be extended to aliphatic amine derived pyridinium salts. This method has the advantages of high efficiency, mild reaction conditions, and broad substrate scope, including primary, secondary, and sterically hindered tertiaryl alkyl substrates, providing a general and practical route for applications in organic synthesis and pharmaceutical studies.

Cellulose nanocrystal (CNC)-based aerogels with extremely low density and hierarchical porous structure were constructed via a facile Pickering-emulsion-templated strategy. In this method, aminated CNCs (CNC-NH

To investigate the effect of the spacers of S-/O-bridged dipyridylamides on the structures of Co(II)/Zn(II) complexes, [Co(L1)(chda)]·1.5H2O (CP1), [Co(L2)(chda)] (CP2), [Zn(L1)(hip)]·DMA·2H2O (CP3), and [Zn(L2)(hip)]·2.8H2O (CP4) [L1 = N,N′-bis(pyridine-3-yl)thiophene-2,5-dicarboxamide, H2chda = trans-1,4-cyclohexanedicarboxylic acid, L2 = N,N′-bis(pyridine-3-yl)-4,4′-oxybis(benzoic) dicarboxamide, H2hip = 5-hydroxyisophthalic acid, DMA = N,N-dimethylacetamide], have been solvothermally synthesized. X-ray single-crystal diffraction shows that CP1 is a 2-D 3,5-connected network based on Co-L1 linear chains and (Co-chda)2 double chains. CP2 features a 1-D structure derived from 1-D wave-like (Co-chda)2 double chains decorated by terminal L2 ligands. CP3 and CP4 show wave-like (4,4) networks constructed by 1-D Zn-L1 zigzag and Zn-hip zigzag (for CP3)/linear (for CP4) chains. The effect of the spacers of S-/O-bridged dipyridylamides on the structures of the title complexes was discussed. Electrochemi...

The objective of the current effort was to determine the efficacy of Fe(II)-montmorillonite (Fe(II)-MMT) as an adjuvant for specific targeted adsorption of phosphate. Specifically, Fe(II)-MMT was studied to combat hyperphosphatemia and anemia arising from chronic renal failure. The adsorption of phosphate over time, pH, and initial concentration was studied. The systems were characterized by X-ray diffraction (XRD), Raman, and zeta potential. The experimental results demonstrated the adsorption time was set to 140 min to achieve maximum adsorption efficiency. It was thus found that the maximum adsorption was at pH 3.0. In addition, it reached equilibrium when the initial phosphate concentration was at 60 mg/L while the maximum adsorption capacity was 5.75 mg of phosphate/g of Fe(II)-MMT. On the other hand, adsorption isotherms showed that the Langmuir model was better than the Freundlich model. This means that the adsorption of the phosphate on Fe(II)-montmorillonites was monolayer adsorption, and the phosphate was successfully adsorbed either onto the surface or intercalated within interlayer volume. Live experiments supported the ability of Fe (II)-MMT to control hyperphosphatemia and treat chronic renal failure.

The nickel-catalyzed fluoromethylation of arylboronic acids was achieved with the industrial raw material fluoromethyl bromide (CH2 FBr) as the coupling partner. The reaction proceeded under mild reaction conditions with high efficiency; it features the use of a low-cost nickel catalyst, synthetic simplicity, and excellent functional-group compatibility, and provides facile access to fluoromethylated biologically relevant molecules. Preliminary mechanistic studies showed that a single-electron-transfer (SET) pathway is involved in the catalytic cycle.

An efficient palladium-catalyzed Heck-type reaction of fluoroalkyl halides, including perfluoroalkyl bromides, trifluoromethyl iodides, and difluoroalkyl bromides, has been developed. The reaction proceeds under mild reaction conditions with high efficiency and broad substrate scope, and provides a general and straightforward access to fluoroalkylated alkenes which are of interest in life and material sciences.

This study investigated the characteristics of liquid phase plasma-electrode catalysis system formed by micro-arc oxidation with titanium-aluminum (Ti-Al) alloy as the anode. Under different power supplies, the wastewater from printing and textile dyeing industries simulated with Rhodamine B (RhB) dye was decolored. We evaluated the impact of oxide film formed on the electrodes on the plasma effects. Our findings showed that repeated applications of opposite voltages could damage the insulating oxide film formed on the electrode surface, contributing to its breakdown and enhancing micro-arc oxidation. Intermittent power supply also modulated the coverage of oxide film by enhancing the cooling of electrolyte. Morphological study of oxide film revealed the presences of rutile and anatase titanium dioxide (TiO

The palladium-catalyzed difluoroalkylation of aryl boronic acids with bromodifluoromethylphosphonate, bromodifluoroacetate, and further derivatives has been developed. This method provides a facile and useful access to a series of functionalized difluoromethylated arenes (ArCF2 PO(OEt)2 , ArCF2 CO2 Et, and ArCF2 CONR(1) R(2) ) that have important applications in drug discovery and development. Preliminary mechanistic studies reveal that a single electron transfer (SET) pathway may be involved in the catalytic cycle.

A preparation of nanometer silver sol by micro arc discharge has been study here through the reduction of Ag3PO4. Sodium citrate and polyvinylpyrrolidone were added respectively into the electrolyte as stabilizer. The results show that, the Ag3PO4 concentration, stabilizer type and concentration have great impacts on the formation of the nanometer silver sol. By means of UV-VIS extinction spectrophotometer, scanning electron microscope and energy dispersive spectrometer, it is found that the solid powder extracted from the electrolyte solution after discharge is the aggregation of the silver formed in the solution and their original size maybe less than 20nm. Nanometer silver with smaller size and narrower size distribution can be obtained with sodium citrate as stabilizer than with polyvinylpyrrolidone. But the latter has higher conversion rate. From this experiment, we found that micro arc discharge can be a rapid, stable preparation method of nanometer silver sol.

An organometallic/inorganic composite Langmuir–Blodgett (LB) film was prepared using a rigid-rod zinc(II) porphyrin platinum(II) complex coordinated with trans -bis(ethynylbenzene) (ZnPPt) as the π-conjugated organometallic molecule, and a europium-substituted polyoxometalate (POM), Na 9 EuW 10 O 36 (EuW 10 ) as the inorganic component. The structure and photophysical properties of the LB film was characterized by π–A isotherms, UV–vis absorption and photoluminescence spectra, atomic force microscopy imaging and scanning tunneling microscopy. The results indicate that stable, well-defined Langmuir and LB films were formed using pure water and POM as subphases. Luminescence spectra of the hybrid LB film showed that the emission spectra were obtained due to the dual-emissive nature of the mixed ZnPPt/EuW 10 blends, and EuW 10 was able to enhance the emission of ZnPPt. The ZnPPt-based LB film displayed an interesting electrical conductivity behavior. The 3-layer film formed by ZnPPt/EuW 10 complex had a strong electrical response, giving rise to a tunneling current up to ± 100 nA when the voltage was monitored at − 1.4–3.1 V. When it was excited by light, the LB composite film generated a photovoltage of 24 μV, indicating that the hybrid film had a strong photovoltage response as well.

Difluoromethylated aromatic compounds are of increasing importance in pharmaceuticals, agrochemicals and materials. Chlorodifluoromethane (ClCF2H), an inexpensive, abundant and widely used industrial raw material, represents the ideal and most straightforward difluoromethylating reagent, but introduction of the difluoromethyl group (CF2H) from ClCF2H into aromatics has not been reported. Here, we describe a direct palladium-catalysed difluoromethylation method for coupling ClCF2H with arylboronic acids and esters to generate difluoromethylated arenes with high efficiency. The reaction exhibits a remarkably broad substrate scope, including heteroarylboronic acids, and was used for difluoromethylation of a range of pharmaceuticals and biologically active compounds. Preliminary mechanistic studies revealed that a palladium difluorocarbene intermediate is involved in the reaction. Although numerous metal-difluorocarbene complexes have been prepared, the catalytic synthesis of difluoromethylated or difluoromethylenated compounds involving metal-difluorocarbene complexes has not received much attention. This new reaction therefore also opens the door to understand metal-difluorocarbene complex catalysed reactions.

A nickel-catalyzed cross-coupling between (hetero)arylborons and unactivated 1-bromo-1,1-difluoroalkanes has been developed. The use of two ligands (a bidentate bipyridine-based ligand, 4,4′-ditBu-bpy, and a monodentate pyridine-based ligand, DMAP) offers a highly efficient nickel-based catalytic system to prepare difluoroalkylated arenes which have important applications in medicinal chemistry.

A nickel-catalyzed cross-coupling between (hetero)arylborons and unactivated 1-bromo-1,1-difluoroalkanes has been developed. The use of two ligands (a bidentate bipyridine-based ligand, 4,4′-ditBu-bpy, and a monodentate pyridine-based ligand, DMAP) offers a highly efficient nickel-based catalytic system to prepare difluoroalkylated arenes which have important applications in medicinal chemistry.

An efficient method for the synthesis of difluoroalkylated alkenes through palladium-catalyzed Heck-type reaction with functionalized difluoromethyl bromides has been developed. The advantages of this protocol are its synthetic simplicity, excellent functional group compatibility, and efficient late-stage difluoroalkylation of biologically relevant molecules, thus paving a new way for application in drug discovery and development. Mechanistic studies revealed that the free difluoroalkyl radicals, initiated by a [Pd(0)Ln] via a single-electron-transfer (SET) pathway, were involved in the Heck-type catalytic cycle.

The spatial and temporal dependence of the surface-enhanced resonance Raman scattering (SERRS) from Nile Blue A (NBA) adsorbed on concentric rings on a gold film was probed. The SERRS intensity mapping of the concentric rings, obtained using linearly polarized excitation, was well-fitted by a sin2 θ function. This spatial variation of SERRS intensity from the nanostructure was in good qualitative agreement with finite-difference time-domain numerical calculations. Histograms of the time-dependent SERRS intensities showed a normal-distribution for concentrations of NBA in the micromolar range and a tailed distribution for diluted solutions (nanomolar range). Time-dependent fluctuations of SERRS intensities were observed when the concentrations of NBA reached 200 nM. The maximum relative SERRS intensity and its absolute variation, obtained from the experiments with diluted solutions, was much lower than previously observed from random substrates that support SERRS, such as colloids immobilized on glass. Thi...

An unprecedented example of Pd-catalyzed difluoromethylation of aryl boronic acids with bromodifluoroacetate is described. The reaction proceeds under mild reaction conditions with hydroquinone and Fe(acac)3 as additives. Preliminary mechanistic studies reveal that a difluorocarbene pathway is involved in the reaction, which is unusual compared to the most traditional approaches. This reaction has advantages of high efficiency and excellent functional group compatibility, even toward bromide and hydroxy group, thus providing a useful protocol for drug discovery and development.

The nickel-catalyzed fluoromethylation of arylboronic acids was achieved with the industrial raw material fluoromethyl bromide (CH2 FBr) as the coupling partner. The reaction proceeded under mild reaction conditions with high efficiency; it features the use of a low-cost nickel catalyst, synthetic simplicity, and excellent functional-group compatibility, and provides facile access to fluoromethylated biologically relevant molecules. Preliminary mechanistic studies showed that a single-electron-transfer (SET) pathway is involved in the catalytic cycle.

Two novel covalently-linked organic-inorganic hybrid compounds [(n-C4H9)4N]2[Mo6O18{≡N–(2-Np)}] (NA–Mo6) and [(n-C4H9)4N]2[Mo6O17{≡N–(1-Np)}2] (NA2–Mo6) (2-Np = 2-naphthyl; 1-Np = 1-naphthyl) have been prepared by the reaction of 2-naphthylamine (2-NpNH2) or 1-naphthylamine (1-NpNH2) with [(n-C4H9)4N]2[Mo6O19] (Mo6) in the presence of N,N′-dicyclohexylcarbodiimide (DCC) in anhydrous acetonitrile, and have been characterized by 1H NMR, IR, UV/Vis, and fluorescence spectra as well as X-ray crystallography. Structural analyses reveal the formation of self-assembled infinite 1-D and 3-D supramolecular frameworks. The UV/Vis spectra of NA–Mo6 and NA2–Mo6 show that the lowest energy electronic transfers occur at 362 and 394 nm, respectively, which are dramatically red-shifted when compared to that of Mo6. The luminescence studies show that Mo6 can notably quench the emission of naphthylamine. Monolayer and multilayer films of NA–Mo6 and NA2–Mo6 were fabricated on different substrates by the Langmuir–Blodgett (LB) technique using H2O as the subphase. For comparison, another two types of organic-inorganic hybrid films composed of noncovalently-linked 1-NpNH2/Mo6 and 2-NpNH2/Mo6 systems were also deposited onto the same substrates under the same conditions by the LB technique using an aqueous solution of Mo6 as the subphase. The as-prepared organic-inorganic hybrid films were characterized by π-A isotherms, UV/Vis absorption spectra, photoluminescence spectra, and scanning tunneling microscopy. The results indicate that stable monolayers can be formed at the air–water interface for NA–Mo6 and NA2–Mo6, and at the air–Mo6 solution interface for 1-NpNH2 and 2-NpNH2. The four LB films containing NA–Mo6, NA2–Mo6, 1-NpNH2/Mo6, and 2-NpNH2/Mo6 display interesting electrical conductivity.

We report a Pd-catalyzed aerobic dehydrogenative cross-coupling of polyfluoroarenes with thiophenes via 2-fold C–H functionalization. The advantages of this reaction are its high reaction efficiency, excellent functional group compatibility, and use of molecular O2 as terminal oxidant. This reaction provides a useful and facile protocol for the preparation of polyfluoroarene–thiophene structure of interest in functional materials. Mechanistic studies revealed that the reaction is initiated by the C–H bond cleavage of polyfluoroarenes.

A new family of organometallic/inorganic composite Langmuir–Blodgett (LB) films consisting of the rigid-rod dinuclear gold(I) complex coordinated with 9,9-bis(4-ethynylphenyl)fluorene (denoted as Au-DPF) as the π-conjugated organometallic molecule coupled with some europium-substituted polyoxometalates (POM; POM = Na9EuW10O36, K13[Eu(SiW11O39)2] and K5[Eu(SiW11O39)(H2O)2]) as the inorganic component were prepared and characterized by π–A isotherms, UV–vis absorption and photoluminescence spectra, atomic force microscopy imaging, scanning tunneling microscopy, and surface photo-voltage spectroscopy. Luminescence spectra of the prepared hybrid LB films show that the near-white emission spectra can be obtained due to the dual-emissive nature of the mixed Au-DPF/POM blends, and POM can facilitate broad aggregate emission bands. These Au-diyne-based LB films displayed interesting electric conductivity behavior. Among them, Au-DPF/K13[Eu(SiW11O39)2] 13-layer film showed a good electrical response, with the tunneling current up to ±100 nA when the voltage was monitored between −1.3 and 1.8 V. The photovoltage response of Au-DPF/EuW22 amounts to 1.5 μV.

An isolated double-hole indentation, with concentric rings, in a metal film was used to obtain highly localized surface-enhanced Raman scattering (SERS) from regions much smaller than the optical wavelength. The structure was created by a focused ion beam (FIB) milling partially through the 100 nm thick gold film to a depth of 50 nm. Significant SERS enhancement was observed for both oxazine 720 and rhodamine 6G. The SERS was polarization-dependent because of the biaxial symmetry of the double-hole at the apexes where the indentations overlap; these apexes were responsible for the strong subwavelength focusing. The finite-difference time-domain method was used to calculate the electromagnetic field of the nanostructure, and it showed strong polarization-dependent focusing, in agreement with the experimentally observed SERS enhancement. On the basis of these calculations, it is estimated that the 60% polarization-dependent SERS enhancement is the result of only ∼1300 molecules in the region of the apexes, ...

An effective and facile method for highly diastereoselective synthesis of quaternary alpha-trifluoromethyl alpha-amino acids was developed in good yields with high diastereoselectivity (dr >20:1) via MgCl(2)-accelerated addition of benzylzinc reagents (Knochel type organozinc reagents) to (R)-phenylglycinol methyl ether based imines of trifluoropyruvate. (C) 2011 Elsevier Ltd. All rights reserved.

The palladium-catalyzed difluoroalkylation of aryl boronic acids with bromodifluoromethylphosphonate, bromodifluoroacetate, and further derivatives has been developed. This method provides a facile and useful access to a series of functionalized difluoromethylated arenes (ArCF2 PO(OEt)2 , ArCF2 CO2 Et, and ArCF2 CONR(1) R(2) ) that have important applications in drug discovery and development. Preliminary mechanistic studies reveal that a single electron transfer (SET) pathway may be involved in the catalytic cycle.

A first example of Pd-catalyzed gem-difluoroallylation of organoborons using 3-bromo-3,3-difluoropropene (BDFP) in high efficiency with high α/γ-substitution regioselectivity has been developed. The reaction can also be extended to substituted BDFPs and has advantages of low catalyst loading (0.8 to 0.01 mol %), broad substrate scope, and excellent functional group compatibility, thus providing a facile route for practical application in drug discovery and development.

To investigate the effect of tumor necrosis factor related apoptosis inducing ligand(TRAIL) on the expression of multidrug resistant genes MDR1, LRP and GST-n in drug-resistant gastric cancer cell strain SGC7901/VCR, and discuss a potential mechanism that reverses the multidrug resistance of gastric cancer with TRAIL as the target point.SGC7901/VCR cell strain was treated over 48 h with TRAIL (50, 100, 200 and 400ig/L, respectively). The expression ofMDR1, LRP, GST-r mRNA in different groups of gastric cell strains was tested by RT-PCR and the expression of P-gp, LRP and GST-n by ELISA.Under the action of TRAIL of different concentrations, different degrees of inhibition were observed in the expression of the mRNA and protein, and the difference from the reference group was statistically significant(p0.01). Except for the insignificant inhibition degree of mRNA and protein in MDR1, LRP and GST-nr as compared between the 400lg/L and the 2001ig/L group(p0.05), the differences between other groups were all statistically significant (p0.05).As preliminarily estimated from the results of the study, TRAILis negatively correlated with drug-resistant genes. It is possible that TRAIL increases the apoptosis and growth inhibition of chemotherapy drug tumor cells by reducing the expression of drug-resistant genes MDR1, LRP and GST-Tt, thereby participating in the reversion of the multidrug resistance of gastric cancer

We report a Pd-catalyzed direct arylation of polyfluoroarenes with aryl iodides. The advantages of this reaction are its high reaction efficiency, excellent functional group compatibility, mild reaction conditions (70 °C), inexpensive PPh(3) ligand, and use of pure water as reaction medium. The usefulness of this reaction has also been demonstrated by rapid preparation of highly functionalized polyfluoroarenes via iterative Pd-catalyzed C-H bond functionalization.

The title process renders possible a highly diastereoselective synthesis (

An efficient highly diastereoselective synthesis of quaternary α-trifluoromethyl amino acids (III) and (V) is developed via allylation of enantiopure imines of trifluoropyruvate (I).

An efficient method for highly diastereoselective synthesis of quaternary α-trifluoromethyl α-amino acids was developed via indium mediated allylation of (R)-phenylglycinol methyl ether based imines of trifluoropyruvate in good yields with high diastereoselectivities at room temperature; to illustrate the application of this method in organic synthesis, 2-allyl-2-(trifluoromethyl) aziridine was prepared in an efficient manner.