When a number of metal ions were tested as activators over a lOO-fold range of metal ion concentration (0.01 to 1.0 mM), aconitase was specifically activated by Fe(II). Manganese(I1) does not activate aconitase but binds to the enzyme, as shown indirectly by inhibition of the enzyme activation by Fe(I1) and directly by electron paramagnetic resonance. A titration of the enzyme with Mn(I1) may b...

The poly(ethyleneimine)-functionalized silica has been developed successfully as an effective adsorbent for the adsorption removal of Cu(II) ions from electroplating wastewater. The influences of pH, contact time and initial concentration of Cu(II) ions on the adsorption capacity and the effect of adsorbent dosage on the removal efficiency of Cu(II) ions from electroplatin...

The complexes of 2-methoxyhenoxyacetates of Mn(II), Co(II), Ni(II) and Cu(II)with the general formula: M(C9H9O4)3·4H2O, where M(II) = Mn, Co, Ni and Cu have been synthesized and characterized by elemental analysis, IR spectroscopy, magnetic and thermogravimetric studies and also X-ray diffraction measurements. The complexes have colours typical for M(II) ions (Mn(II) a pale pink, Co(II) pink, N...

Cr(III), Mn(II), Fe(III), Co(II) and Ni(II) complexes of N-(2-nitro)-benzilidene-3-hydrazino benzoxazine-2-one (NBHBO) have been synthesized and characterized by elemental analysis, conductance, thermal, spectral and magnetic data. NBHBO acts as a bidentate NN donor towards trivalent and NO donor towards divalent metal ions. Octahedral geometries have been proposed for all the Complexes. The li...

Zero-dimensional (0D) tetrahedral Mn(II) halides (MnX42– (X = Cl, Br, I)) have emerged as solid-state green emitters with high photoluminescence quantum yield (PLQY). However, their PLQYs are significantly dependent on the environment surrounding Mn(II), i.e., organic cation and halide. Although bromide is highly emissive, iodide exhibits relatively low PLQY. Herein, we report preparation of or...

When a number of metal ions were tested as activators over a lOO-fold range of metal ion concentration (0.01 to 1.0 mM), aconitase was specifically activated by Fe(II). Manganese(I1) does not activate aconitase but binds to the enzyme, as shown indirectly by inhibition of the enzyme activation by Fe(I1) and directly by electron paramagnetic resonance. A titration of the enzyme with Mn(I1) may b...

The adsorption of Mn(II) and Co(II) ions from aqueous solution was investigated using batch adsorption experiment at room temperature. The effect of pH, contact time, metal ion concentration and temperature were evaluated. The residual concentrations of the metal ions were determined by atomic absorption spectrophotometer. The results showed that maximum removal of Mn(II) and Co(II) ions occurr...

A new procedure for the determination of chromium species in polluted environmental samples by flame atomic absorption spectrometry was developed in this work. A new material containing 1,5-diphenylcarbazone included in a polymeric matrix was prepared and employed as a solid-phase extraction material for selective separation of Cr(III) ions under dynamic conditions. Chromium(III) ions were reta...

Photosynthetic water oxidation is catalyzed by the Mn4CaO5 cluster of photosystem II. The assembly of the Mn4O5Ca requires light and involves a sequential process called photoactivation. This process harnesses the charge-separation of the photochemical reaction center and the coordination environment provided by the amino acid side chains of the protein to oxidize and organize the incoming mang...