Heck reaction catalyzed by cobalt hollow nanospheres has been developed; the coupling of alkenes with aryl iodide or aryl bromide in the presence of potassium carbonate provides the corresponding products with moderate to good yields, which reveals obvious advantages such as low-cost catalyst, ligand-free condition, the recyclability of the catalyst and simple experimental operation.

The electroreduction of aryl halides (bromides or chlorides) allows the coupling reaction with vinylic acetates, in the presence of 2,2-bipyridine and catalytic amounts of cobalt bromide, leading to styrene derivatives in good yields. q 2003 Elsevier Science Ltd. All rights reserved.

Submit Manuscript | http://medcraveonline.com Abbreviations: CMGG: Carboxymethyl Guar Gum; BMMscs: Bone Marrow Derived Mesenchymal Stem Cells; DMEM: Dulbecco’s Modified Eagle Medium; FBS: Foetal Bovine Serum; Pen-Strep: Penicillin-Streptomycin; LPS: Lipopolysaccharide; Cocl2.6H2O: Cobalt Chloride Hexahydrate; PBS: Phosphate Buffered Saline; EDTA: Ethylene Diamine Tetra Acetic Acid; MTT: 3-(4, 5...

A simple and new simultaneous fourth derivative spectrophotometric method is proposed for the analysis of a two-component system containing cobalt(II) and nickel(II) without separation using 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC) as a chromophoric reagent. The reagent reacts with cobalt(II) and nickel(II) at pH 6.0, forming soluble brown and yellow colored species, respect...

The influence of halide and isothiocyanate ions of the reduction wave of aquopentamminecobalt(‡V) and aquopentamminechromium(‡V) ions at the dropping mercury electrode has been studied by the measurements of current-potential and current-time curves. The cobalt (‡V) complex ion gives a kinetic-controlled reduction wave at more positive potentials than that of the reduction of cobalt(‡V) to coba...

in this paper, macrocyclic cobalt(ii) complexes [col1](no3)2.4h2o (1) and [col2](no3)2.2h2o (2) have been synthesized from the reaction of dialdehydes 1,2-bis(2-formylphenyl)ethane and 1,3-bis(2-formylphenyl)propane, co(no3)2.6h2o and 1,2-cyclohexanediamine with molar ration 1:1:1 in methanole and characterized by elemental analyses and ft-ir spectroscopy. then used as precursors for preparatio...

Mediation of reversible deactivation radical polymerization (RDRP) by cobalt(II) complexes (CMRP) is the most highly developed subcategory of organometallic mediated RDRP (OMRP). Attention was paid to CMRP for its unusual high efficiency observed for the control of acrylate and vinyl acetate polymerization that produced homo- and block copolymers with narrow molecular weight distribution and a ...

Cobalt (II) reacts with 5-methylfuran-2-carbaxaldehyde thiosemicarbazone (5-MFAT) and forms a light yellow colored complex, which was extracted into isobutanol from sodium acetate and acetic acid buffer at pH 6.0. The absorbance value of the Co (II)–5-MFAT complex was measured at different intervals of time at 360 nm, to ascertain the time stability of the complex. The extraction of the complex...

FrmR from Salmonella enterica serovar typhimurium (a CsoR/RcnR-like transcriptional de-repressor) is shown to repress the frmRA operator-promoter, and repression is alleviated by formaldehyde but not manganese, iron, cobalt, nickel, copper, or Zn(II) within cells. In contrast, repression by a mutant FrmRE64H (which gains an RcnR metal ligand) is alleviated by cobalt and Zn(II). Unexpectedly, Fr...

cobalt is widely used in different industrial processes for production of various synthetic materials. for assessment of human exposure to toxic metal of co (ii), environmental and biological monitoring are essential processes, in which, preparation of samples is one of the most time-consuming and error-prone aspects prior to instrumental analysis. the aim of this study was to achieve optimum f...