Diazacrown ethers having two carbodithioate groups were synthesized, and their spectrophotometric properties were studied. Diammonium 1,4,10,13-tetraoxa-7,16-diazacycrooctadecane-N,N'-bis(carbodithioate) (DA18CC) and ammonium 1,4,10-trioxa-7,13-diazacycropentadecane-N,N'-bis(carbodithioate) (DA15CC) reacted with most heavy-metal ions through their two carbodithioate groups, and also reacted wit...

heavy metal toxicity has serious adverse effects on the environment. the metal sequestering characteristics of a novel metal binding peptide (glu-cys) 11 gly+linker+hexahistidine (ec 11 :his 6 ) was investigated to determine if it can absorb cu 2+ or zn 2+ cations. molecular dynamics simulations were carried out using a model of 6 cu 2+ or zn 2+ and other ions enclosed in a fully hydrated simul...

The electrochemical properties of diazophenylcalix[4]arenes bearing ortho-carboxyl group (o-CAC) and ortho-ester group (o-EAC), respectively, in the presence of various metal ions were investigated by voltammetry in CH3CN. o-CAC and o-EAC showed voltammetric changes toward divalent metal ions and no significant changes with monovalent alkali metal ions. However, o-CAC preferentially binds with ...

of past research 1) The individual and competitive adsorption of metal ions on graphene oxides (GOs) studies by experimental and DFT calculation The heavy metal ions can be accumulated in living tissues, so they must be removed from polluted water. Graphene oxides (GOs) are considered as the ideal adsorbent material because the large quantities of oxygen-containing functional groups strengthen ...

the complexation reactions between tl+ and pb2+ ions and crown ethers 12-crown-4(12c4), 15-crown-5 (15c5), benzo-15-crown-5 (b15c5), 18-crown-6 (18c6), dicyclohexyl-18-crown-6 (dc18c6) and aza-18-crown-6 (a18c6) were studied in 90% acetonitrile and 90% ethanol solutions at 25 °c, using an a.c. polarographic technique. the stoichiometry and stability of the complexes were determined by monitorin...

chelating resins based on polyacrylonitrile and diethylenetriamine (pan-dta) wereprepared through the simple reaction of polyacrylonitrile with various volume percents ofdiethylenetriamine (dta), (25, 50, 75 and 100). the prepared resins were applied to removeheavy metal ions such as cu(ii), zn(ii) and cd(ii) from aqueous solutions. the sorptionbehaviors of the resins for these metal ions were ...

the biosorption of heavy metals can be an effective process for the removal of such metal ions from aqueous solutions. in this study, the adsorption properties of nonliving biomass of phanerochaete chrysosporium for pb (ii) and zn (ii) were investigated by the use of batch adsorption techniques. the effects of initial metal ion concentration, initial ph, biosorbent concentration, stirring speed...

The hydrolysis of p-nitrophenyl acetate catalysed by pectin methylesterase is competitively inhibited by pectin and does not require metal ions to occur. The results suggest that the activastion by metal ions may be explained by assuming that they interact with the substrate rather than with the enzyme. With pectin used as substrate, metal ions are required in order to allow the hydrolysis to o...

The structure and activity of nucleic acids depend on their interactions with metal ions. Fundamental to these interactions is the degree of specificity observed between the metal ions and nucleic acids, and a complete description of nucleic acid folding requires that we understand the nature of the interactions with metal ions, including specificity. The prior demonstration that high concentra...