The effects of nitrogenous synergists on the potentiometric responses to divalent transition metal ions were investigated concerning polymeric liquid membranes containing thenoyltrifluoroacetone (Htta) as an ionophore. The tested synergists were pyridine (py) and 4,4'-dioctyl-2,2'-bipyridyl (C8bpy). The potentiometric responses to metal ions, such as Cd2+, Co2+, Ni2+ and Zn2+, were induced by a...

The precise analysis of redox chemistry of MN4-based macrocyclic complexes is of great importance because of stabilization of unusual oxidation states of metal ions by macrocyclic ligand and thus have various applications in biochemistry, electrochemistry, electrocatalysis, pharmaceuticals etc. In this work, MN4-macrocyclic complexes of Co (II) and Ni(II) transition metal ...

The observed rates of ribozyme cleavage reactions are strongly dependent on the nature of the metal ion present. Metal ions can thereby exhibit a stronger inhibiting or accelerating effect compared to Mg(2+), which is usually considered the natural cofactor. Alkaline, alkaline earth, transition, d(10), and other metal ions are applied either to gain a spectroscopic handle on the metal center, a...

background: the present study investigated the effect of the middle east dust storm episodes on the concentration and composition of pm 10 during april to september 2013 in sanandaj city, western iran. methods: sampling was once every six days, and on dusty days using an omni air sampler. the pm 10 sample was collected on polytetrafluoroethylene filters. average of 24 h values of pm 10 mass con...

background: mushroom tyrosinase a potent candidate in clinical studies known as polyphenol oxidase, is a metaloenzyme from the oxidase superfamily widely distributed from lower to higher life forms. it plays a crucial role in sclerotization of exoskeleton in insects, also responsible for skin pigmentation in mammalians. objective: in this study, after reconstitution of mt by some metal ions, th...

By utilizing different coordination properties of a lanthanide ion and a transition metal ion, a heterometallo-supramolecular polymer with Eu(III) and Fe(II) ions introduced alternately (polyEuFe) was precisely prepared via stepwise complexation of the metal ions to a new unsymmetrical ligand with both a dicarboxylate-substituted terpyridine and an unsubstituted terpyridine. The polymer showed ...

the complexation reactions between cu2+, pd2+ and ni2+ metal ions with promethazine (pm) in water or dmf were studied by the spectrophotometric methods at [(15, 25,35 and 45±0.1) °c]. the complexation process was optimized in terms of ph, temperature and contact time. the stoichiometry of the complex was found to be 1:1 (metal ion/ligand). the formation constants of the resulting complexes were...

Salicylic acid-Formaldehyde-m-Cresol (SFM) terpolymer had been synthesized in DMF media by conventional method. The resulting resin had been characterized by FTIR spectra, elemental and thermogravimetric analyses. The morphology of SFM resin had been studied by SEM and Optical photograph. Various parameters like rate of equilibration, effect of pH on ion exchange capacity and effect of conc...

Two N4-type Schiff base ligands named N,N'-bis(2-pyridylmethylidene)-1,2-diiminoethane (L1) and N,N'-bis(2-pyridylmethylidene)-1,3-diiminopropane (L2) have been synthesized by the reaction of pyridine-2-carbaldehyde with ethylenediamine and propylenediamine, respectively. The binding abilities of L1 and L2 in dichloromethane towards Cu<...

Nanocrystals prepared in organic media can be easily self-assembled into close-packed hexagonal monolayers on solvent evaporation for various applications. However, they usually rely on the use of organometallic precursors that are soluble in organic solvents. Herein we report a general protocol to transfer metal ions from an aqueous solution to an organic medium, which involves mixing the aque...