359 research outputs found

    Electrochemical alcohols oxidation mediated by N-hydroxyphthalimide on nickel foam surface

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    Alcohol to aldehyde conversion is a critical reaction in the industry. Herein, a new electrochemical method is introduced that converts 1 mmol of alcohols to aldehydes and ketones in the presence of N-hydroxyphthalimide (NHPI, 20 mol%) as a mediator; this conversion is achieved after 8.5 h at room temperature using a piece of Ni foam (1.0 cm2) and without adding an extra-base or a need for high temperature. Using this method, 10 mmol (1.08 g) of benzyl alcohol was also successfully oxidized to benzaldehyde (91%) without any by-products. This method was also used to oxidize other alcohols with high yield and selectivity. In the absence of a mediator, the surface of the nickel foam provided oxidation products at the lower yield. After the reaction was complete, nickel foam (anode) was characterized by a combination of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), and spectroelectrochemistry, which pointed to the formation of nickel oxide on the surface of the electrode. On the other hand, using other electrodes such as Pt, Cu, Fe, and graphite resulted in a low yield for the alcohol to aldehyde conversion

    Ethyl [(2-hydroxy­phen­yl)(pyridinium-2-ylamino)meth­yl]phospho­nate methanol solvate

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    In the title compound, C14H17N2O4P·CH3OH, the planes of the pyridinium-2-ylamino and 2-hydroxy­phenyl groups form a dihedral angle of 75.6 (1)°, with the pyridinium NH group and the 2-hydroxy­phenyl OH group pointing in opposite directions. Three intra­molecular hydrogen bonds are observed. Two phospho­nate and two methanol mol­ecules are connected by O—H⋯O hydrogen bonds as a centrosymmetric dimeric cluster, and inter­act further with other dimeric clusters via N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds and C—H⋯π inter­actions, resulting in a sheet structure

    Diethyl [hydr­oxy(phen­yl)meth­yl]phospho­nate

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    Mol­ecules of the title compound, C11H17O4P, are linked into chiral helical chains along the crystallographic b axis via O—H⋯O hydrogen bonds between the hydr­oxy group and an O atom of the phospho­nate group. One ethyl group is disordered over two positions; the site occupancy factors are ca 0.7 and 0.3

    Modification of nano-clays with ionic liquids for the removal of Cd (II) ion from aqueous phase

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    The present study attempts to synthesize nano-modified clays of Na-bentonite (Bent) and montmorillonite (MT), using three imidazolium-based ionic liquids (ILs) including 3,3′-(hexyl)bis(3-methylimidazolium) bromide chloride ([H(mim)2[Br][Cl]), 1-hexyl-3-methylimidazolium chloride ([Hmim][Cl]) and 1-octyl-3-methylimidazolium chloride ([Omim][Cl]). X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), carbon, hydrogen and nitrogen elemental analysis (CHN), scanning electron microscope (SEM) and specific surface area (SSA) (using N2-BET) techniques provided evidence of successful modification of the guest clays. Removal of Cd (II) from aqueous phase was investigated using the modified clays under different experimental conditions of reaction time, pH and adsorbent dosage. Detailed isotherms and kinetic studies showed that the modified clays have much higher Cd (II) adsorption capacity compared to those of the starting clay minerals. The maximum Cd (II) absorption capacities of 87.46 and 94.6 mg g−1 were observed in [H(mim)2]-MT and [H(mim)2]-Bent with d-values of 35.4 Å and 28.3 Å respectively. The [Omim]-clays had the highest adsorption affinities of Cd (II) in initial concentrations of Cd (II). This study shows that ILs could enhance the clay capacity and tendency for Cd (II) absorption with different trends based on the ILs structures. The modified clays using ILs are green and eco-friendly adsorbents and due to substantial increase in their capacity for the removal of heavy metals, they could have positive economic and environmental impacts

    Homogeneous and heterogeneous catalysts for multicomponent reactions

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    [EN] Organic synthesis performed through multicomponent reactions is an attractive area of research in organic chemistry. Multicomponent reactions involve more than two starting reagents that couple in an exclusive ordered mode under the same reaction conditions to form a single product which contains the essential parts of the starting materials. Multicomponent reactions are powerful tools in modern drug discovery processes, because they are an important source of molecular diversity, allowing rapid, automated and high throughput generation of organic compounds. This review aims to illustrate progress in a large variety of catalyzed multicomponent reactions performed with acid, base and metal heterogeneous and homogeneous catalysts. Within each type of multicomponent approach, relevant products that can be obtained and their interest for industrial applications are presented.The authors wish to gratefully acknowledge the Generalitat Valenciana for the financial support in the project CONSOLIDER-INGENIO 2010 (CSD2009-00050)Climent Olmedo, MJ.; Corma Canós, A.; Iborra Chornet, S. (2012). Homogeneous and heterogeneous catalysts for multicomponent reactions. RSC Advances. 2(1):16-58. https://doi.org/10.1039/c1ra00807bS16582

    Understanding the potential in vitro modes of action of bis(β‐diketonato) oxovanadium(IV) complexes

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    To understand the potential in vitro modes of action of bis(β-diketonato) oxovanadium(IV) complexes, nine compounds of varying functionality have been screened using a range of biological techniques. The antiproliferative activity against a range of cancerous and normal cell lines has been determined, and show these complexes are particularly sensitive against the lung carcinoma cell line, A549. Annexin V (apoptosis) and Caspase-3/7 assays were studied to confirm these complexes induce programmed cell death. While gel electrophoresis was used to determine DNA cleavage activity and production of reactive oxygen species (ROS), the Comet assay was used to determine induced genomic DNA damage. Additionally, Förster resonance energy transfer (FRET)-based DNA melting and fluorescent intercalation displacement assays have been used to determine the interaction of the complexes with double strand (DS) DNA and to establish preferential DNA base-pair binding (AT versus GC)
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