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The antitumor activity of imidazolium salts is highly dependent upon their lipophilicity that can be tuned by the introduction of different hydrophobic substituents on the nitrogen atoms of the imidazolium ring of the molecule. Taking this into consideration, we have synthesized and characterized a series of tripodal imidazolium salts derived from l-valine and l-phenylalanine containing different hydrophobic groups and tested them against four cancer cell lines at physiological and acidic pH. At acidic pH (6.2) the anticancer activity of some of the tripodal compounds changes dramatically, and this parameter is crucial to control their cytotoxicity and selectivity. Moreover, several of these compounds displayed selectivity against the control healthy cell line higher than four. The transmembrane anion transport studies revealed moderate transport abilities suggesting that the observed biological activity is likely not the result of just their transport activity. The observed trends in biological activity at acidic pH agree well with the results for the CF leakage assay. These results strongly suggest that this class of compounds can serve as potential chemotherapeutic agents.

In this study, we report a facile and effective production process of palladium nanoparticles supported on polypyrrole/reduced graphene oxide (rGO/Pd@PPy NPs). A novel electrochemical sensor was fabricated by incorporation of the prepared NPs onto glassy carbon electrode (GCE) for the simultaneous detection of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The electrodes modified with rGO/Pd@PPy NPs were well decorated on the GCE and exhibited superior catalytic activity and conductivity for the detection of these molecules with higher current and oxidation peak intensities. Simultaneous detection of these molecules was achieved due to the high selectivity and sensitivity of rGO/Pd@PPy NPs. For each biomolecule, well-separated voltammetric peaks were obtained at the modified electrode in cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements. Additionally, the detection of these molecules was performed in blood serum samples with satisfying results. The detection limits and calibration curves for AA, DA, and UA were found to be 4.9 × 10−8, 5.6 × 10−8, 4.7 × 10−8 M (S/N = 3) and ranging from 1 × 10−3 to 1.5 × 10−2 M (in 0.1 M PBS, pH 3.0), respectively. Hereby, the fabricated rGO/Pd@PPy NPs can be used with high reproducibility, selectivity, and catalytic activity for the development of electrochemical applications for the simultaneous detection of these biomolecules.

Sodium-ion batteries (SIBs) have undergone extensive research efforts as compatible successors of Li-ion batteries (LIBs) for grid-scale energy storage owing to the abundance of sodium resources. However, the poor cycling stability and low rate capability of existing anodes has prevented the practical application of SIBs. To mitigate the situation we have created a 3D heterostructure electrode based on alternative layers of 2D (MoS2-graphene) and 1D (CNTs) materials via a hydrothermal route that is fundamentally different from the usual composites. For comparison, composites were prepared using the same experimental conditions with either rGO or MWCNTs. While discharging at 100 mA g(-1) and 500 mA g(-1), the MoS2-MWCNT@rGO could deliver a high discharge capacity of 664 mA h g(-1) and 551 mA h g(-1), and retained 100% and 98.4% capacity after 80 and 250 discharge-charge cycles, respectively. At 2 A g(-1), it can yield an initial discharge capacity of 375 mA h g(-1), maintaining 81.3% and 67% capacity after 250 and 500 cycles, respectively. The excellent performance of the MoS2-MWCNT@rGO hybrid is mainly attributed to the robust MWCNT@rGO framework with improved 3D electrical conductivity, additional porosity and excellent buffering capability. Furthermore, an in situ TEM technique was employed to explore the sodiation mechanism of the MoS2 nanosheets.

Dyes are classified as one of the major pollutants of water. They have negative impacts not only on environment but also on human health. In fact, wastewater that contains these harmful substances requires many types of treatments. Therefore, alternative methods and adsorption agents are needed. Herein, we propose to evaluate the decolorization of methylene blue (MB) and methyl orange (MO) as two models of soluble dyes from water using chitin and chitosan-graft-polyacrylamide. Furthermore, the applicability of these biomacromolecules as alternative adsorption agents, their sticking probability and desorption were also examined. Experimental parameters such as dye concentration, contact time, pH solution, adsorbent dosage and temperature were thoroughly examined for the grafted chitosan and chitin. The activation energy ( E a ) and the thermodynamic variables (i.e., standard Gibb&rsquo, s free energy ( &Delta, G 0 ), standard enthalpy ( &Delta, H 0 ), and standard entropy ( &Delta, S 0 )) were determined using the Van&rsquo, t Hoff and Arrhenius equations. The sticking probability ( S *) model for MB and MO removal by chitin and the chitosan derivative demonstrated that both dyes were successfully removed under the proposed conditions. Desorption studies of MB and MO showed the reusability of both materials, suggesting their application for removing dyes from aqueous solution.

We report the microwave synthesis of several bis(thiosemicarbazones) and the rapid gallium-68 incorporation to give the corresponding metal complexes. These proved kinetically stable under ‘cold’ and ‘hot’ biological assays and were investigated using laser scanning confocal microscopy, flow cytometry and radioactive cell retention studies under normoxia and hypoxia. 68Ga complex retention was found to be 34% higher in hypoxic cells than in normoxic cells over 30 min, further increasing to 53% at 120 min. Our data suggests that this class of gallium complexes show hypoxia selectivity suitable for imaging in living cells and in vivo tests by microPET in nude athymic mice showed that they are excreted within 1 h of their administration.

Synthesis of mesoporous strontium hydroxyapatite (SrHAp) nanorods was carried out in a microwave without using any capping agent or surfactant. Nanorod formation was successfully achieved even at temperatures as low as 140 degrees C with 1 min hold time. Field emission gun transmission electron microscopy (FEG-TEM) and scanning electron microscopy (SEM) indicated monodisperse, uniform and mesoporous nanorods with average dimensions: length 98.87 nm, width 18.87 nm and pore size 2-5 nm. XRD analysis showed that the sample consisted of a single phase made up of highly crystalline nanorods with a P6(3)/m symmetry group. Fourier transform infrared spectroscopy (FTIR) and energy dispersive X-ray spectroscopy (EDX) confirmed that the chemical and elemental composition was that of strontium hydroxyapatite. Surface area and pore volume were calculated from nitrogen adsorption and desorption isotherms as 40.13 m(2) g(-1) and 0.45 cm(3) g(-1), respectively. The material was found to be non toxic to NIH3T3, MCF-7 and Zr-75 cells even at concentrations of 0.25 mg ml(-1), and after 24 and 48 hours of incubation. Thus, owing to its high surface area, pore volume and good cell viability, this material showed good potential for anticancer and other drug delivery applications.

Haloaryl phosphates (X-dippH(2), X = Cl, Br, I) react with zinc acetate in the presence of collidine or 2-aminopyridine (2-apy) to yield zinc phosphate clusters [Zn(X-dipp)(collidine)]4 (X = Cl (1), Br (2), I (3)) and [Zn(X-dipp)(2-apy)](4)center dot 2MeOH (X = Cl (4), Br (5), I (6)), respectively. Single-crystal X-ray diffraction studies reveal that collidine and 2-apy capped zinc phosphates 1-6 exist as discrete tetrameric zinc phosphate molecules, exhibiting a cubane-shaped D4R core. In contrast, when the same reaction has been carried out in the presence of 4-cyanopyridine (4-CNpy), polymeric zinc phosphates {[Zn-4(X-dipp)(4)(4-CNpy)(2)(MeOH)(2)]center dot 2H(2)O}(n) (X = Cl (7), Br (8), I (9)) have been isolated. Compounds 7-9 are square-wave-shaped, one-dimensional polymers composed of fused S4R repeating units. The common structural motif found both in D4R cubanes 1-6 and polymers 7-9 is the S4R building block, which presumably undergoes further fusion because of the coordinative unsaturation at zinc and the simultaneous presence of free P=O. The closed shell cubanes 1-6 are obviously formed by a face-to-face dimerization involving two S4R units in which the two P=O groups are in cis-configuration. On the other hand, the one-dimensional (1-D) square-wave polymers 7-9 are formed from a face-to-face association of S4R building units in which the two P=O groups are in a trans-configuration. In order to stabilize these elusive S4R zinc phosphates, the reaction between Cl-dippH2 and zinc acetate was carried out in the presence of excess imidazole as an ancillary ligand (1:1:4), although only an imidazole decorated cubane cluster [Zn(Cl-dipp)(imz)]4.2MeOH (10) was isolated. The chelating N,N'-donor 1,10-phenanthroline ligand was used to eventually isolate cyclic S4R phosphate [Zn(mu(2)-Cl-dipp)(1,10-phen)(OH2)](2)center dot MeOH center dot H2O (11). The change of Zn2+ source to zinc nitrate and the phosphate source to 2,6-dimethylphenyl phosphate (dmppH2) led to the isolation of another polymeric phosphate [Zn(dmpp)(MeOH)](n) (12), with a zigzag backbone, formed through an edge-to-edge to polymerization of S4R building units with P=O groups in trans-configuration. The isolation of four different structural types of zinc phosphates A-D in the present study can be rationalized in terms of fusion of S4R rings in a variety of ways to either produce discrete clusters or 1-D polymers.

In this study we present a three-step process for the low-temperature chemical bath deposition of crystalline ZnO films on glass substrates. The process consists of a seeding step followed by two chemical bath deposition steps. In the second step (the first of the two bath deposition steps), a natural polysaccharide, namely hyaluronic acid, is used to manipulate the morphology of the films. Previous experiments revealed a strong influence of this polysaccharide on the formation of zinc oxide crystallites. The present work aims to transfer this gained knowledge to the formation of zinc oxide films. The influence of hyaluronic acid and the time of its addition on the morphology of the resulting ZnO film were investigated. By meticulous adjustment of the parameters in this step, the film morphology can be tailored to provide an optimal growth platform for the third step (a subsequent chemical bath deposition step). In this step, the film is covered by a dense layer of ZnO. This optimized procedure leads to ZnO films with a very high electrical conductivity, opening up interesting possibilities for applications of such films. The films were characterized by means of electron microscopy, X-ray diffraction and measurements of the electrical conductivity.

High quality CoFe2O4 nanoparticles were synthesized using a one-pot, microwave assisted method, that allows forming stable colloidal solutions in alcoholic solvents, as required for the preparation by Chemical Solution Deposition of hybrid nanocomposite ferromagnetic-high Tc YBa2Cu3O7 superconducting films or devices. We have investigated how the thermal process necessary for the preparation of such epitaxial nanocomposites, involving high temperatures (800 °C) and oxygen partial pressures (1 atm), affects the structure and magnetic properties of the isolated nanoparticles. The NPs were fully characterised by XRD, SQUID, STEM-EELS and XMCD at four different stages of the thermal process. Results show that, despite intermediate changes in the cation distribution occur during the process, the final NP magnetization is stable against the thermal treatment. This result opens up perspectives for the preparation of hybrid YBCO films with embedded magnetic NPs using low-cost chemical-solution methods, Authors acknowledge the MICIN (NANOSELECT, CSD2007-00041 and MAT2014-51778-C2-1-R and FEDER), Generalitat de Catalunya (2014SGR 753 and Xarmae), ‘‘Severo Ochoa’’ Programme for Centres of Excellence in R&D (SEV-2015-0496), the CONSOLIDER Excellence Network (MAT2015-68994-REDC) and the EU (EU-FP7 NMP-LA-2012- 280432 EUROTAPES project). Electron microscopy performed at the Centro Nacional de Microscopı´a Electro´nica (UCM) was sponsored by the ERC Starting Investigator Award No. STEMOX#239739. J. G. and M. C. also acknowledge the Ramon y Cajal program (RYC-2012- 11709, RYC-2013-12448). The XMCD experiments were performed at the BOREAS beamline of the ALBA Synchrotron Light Facility with the collaboration of ALBA staff.

Metal Chalcogenides (MCs) have emerged as an extremely important class of nanomaterials with applications ranging from lubrication to energy storage devices. Here we report our discovery of a universal, ultrafast (60 seconds), energy-efficient, and facile technique of synthesizing MC nanoparticles and nanostructures, using microwave-assisted heating. A suitable combination of chemicals was selected for reactions on Polypyrrole nanofibers (PPy-NF) in presence of microwave irradiation. The PPy-NF serves as the conducting medium to absorb microwave energy to heat the chemicals that provide the metal and the chalcogenide constituents separately. The MCs are formed as nanoparticles that eventually undergo a size-dependent, multi-stage aggregation process to yield different kinds of MC nanostructures. Most importantly, this is a single-step metal chalcogenide formation process that is much faster and much more energy-efficient than all the other existing methods and can be universally employed to produce different kinds of MCs (e.g., MoS2, and WS2). NASA LEARN II [NNX14AF49A] We gratefully acknowledge financial support from NASA LEARN II NNX14AF49A. We thank Dr. Runzhe Tao for technical assistance for this experiment.

Magnetic iron oxide nanoparticles (IONs) with controllable physicochemical and magnetic properties were synthesized by a fast and simple solvothermal microwave (MW) assisted approach. The MW-assisted synthesis using a coaxial microwave antenna was carried out in different routes: (i) a fast one-step solvothermal approach, and (ii) a non-aqueous sol-gel system. This innovative configuration obtained IONs maghemite crystal phase, in a very short reaction time (from 5 to 15 min), with a small size (6 nm) and narrow particle size distribution. Magnetization as a function of the applied magnetic field revealed that all the samples showed superparamagnetisms, with a saturation magnetization ranging from 60 to 68 emu g(-1) (T = 300 K). TEM, XRD, FTIR, TG, and magnetic measurements were used to fully characterize the IONs. Not only did the proposed methodologies using the coaxial MW configuration produce IONs with similar or improved physicochemical and magnetic properties, but they also overcame the classical drawbacks of oven-type MW configurations.

Copper sulphide crystallizes in a variety of phases that exhibit distinct optical properties including different optical band gaps in the visible region. The crystalline phases are associated with unique properties shown by semiconductor nanocrystals that could be exploited to produce new photocatalysts with tuned optical behavior. This research reports on the use of ionic liquids as a reaction medium to produce copper sulphide nanocrystals whose crystalline phase depends on the synthesis conditions. Noteworthy, these solvents allow the production of water dispersible copper sulphides following the thermal treatment of Cu(II) alkyldithiocarbamates complexes, used here as single-molecule precursors, thus improving their potential for heterogeneous photocatalysis in the aqueous phase. Finally, the ensuing copper sulphides have been preliminarily assessed for their photocatalytic activity in the degradation of rhodamine B (RhB). The results indicate that the ionic liquid route described here has an impact on the copper sulphides produced and thereby on their performance as photocatalysts.

Activated: The title reaction proceeds efficiently with 1 mol % of palladium and gives tetrahydroquinolines in excellent enantioselectivities (see scheme). The enantiodiscriminating concerted metalation-deprotonation step occurs via a rare seven-membered palladacycle. The cyclopropyl-substituted tetrahydroquinolines can be regioselectively and enantiospecifically reduced to chiral tetrahydrobenzoazepines. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CdO hexagonal sheets were prepared by a simple chemical route assisted by microwave irradiation. Two different preparation procedures were adopted and characterized in the presence of urea as a directing agent and poly-vinyl-pyrrolidone (PVP) as a surfactant. The morphological and microstructural characteristics were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) analysis, diffuse reflectance infrared spectroscopy (DRIFT) and X-ray powder diffraction (XRD). Characterization results have demonstrated that, after annealing at 300 °C, the formation of CdO hexagonal sheets with different thickness. Thicker sheets were obtained when urea and PVP were used. Chemoresistive devices consisting of a thick layer of CdO hexagonal sheets on interdigitated alumina substrates had been fabricated and their electrical and sensing characteristics were investigated. The sensor performances of the CdO sheets for carbon monoxide were reported. The results indicated that both the sensors exhibited high response and quick response-recovery dynamics. The sensing properties were explained in terms of rapid gas diffusion onto the sensing layer surface.

Diethyl phosphonates and tetraethyl alkyldiphosphonates were efficiently and rapidly prepared via the Michaelis–Becker reaction, under microwave irradiation. These compounds were then hydrolyzed to phosphonic and diphosphonic acids or selectively monodealkylated to give monoesters of phosphonic acids and symmetrical diethyl esters of diphosphonic acids. These reactions were also achieved rapidly in satisfactory yields with microwave methodology. This methodology was applied with success to the functionalization of a polymer resin. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:369–377, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20561