Ternary and quaternary metal chelates of some biologically important bivalent transition metal ions viz. Co(II), Ni(II), Cu(II) and Zn(II) formed with biologically significant ligands, viz. Asparagine (A) and Uracil (B) have been investigated. The relevant stability constants and complexation equilibria of quaternary metal chelates in solution at 30±1 oC and at constant ionic strength (I=0.1M N...

We demonstrate the mixed annihilation electrogenerated chemiluminescence of tris(2,2'-bipyridine)ruthenium(ii) with various cyclometalated iridium(iii) chelates. Compared to mixed ECL systems comprising organic luminophores, the absence of T-route pathways enables effective predictions of the observed ECL based on simple estimations of the exergonicity of the reactions leading to excited state ...

The preparation and characterization of new model complexes for the molybdenum cofactor are reported. The new models are distinctive for the inclusion of pterin-substituted dithiolene chelates and have the formulation Tp(*)MoX(pterin-R-dithiolene) (Tp(*)=tris(3,5,-dimethylpyrazolyl)borate), X=O, S, R=aryl. Syntheses of Mo(4+) and (5+) complexes of two pterin-dithiolene derivatives as both oxo a...

Lead (Pb), depending upon the reactant surface, pH, redox potential and other factors can bind tightly to the soil with a retention time of many centuries. Soil-metal interactions by sorption, precipitation and complexation processes, and differences between plant species in metal uptake efficiency, transport, and susceptibility make a general prediction of soil metal bioavailability and risks ...

Simultaneous extraction of the morpholino dithiocarbamate (MDTC) chelates of Cr(III) and Cr(VI) ion from aqueous samples was accomplished by applying fabric phase sorptive extraction (FPSE) using a cellulose fabric modified with a sol-gel/polytetrahydrofuran composite. Following extraction, the chelates were separated by HPLC on a reverse phase C18 column with acetonitrile:water (65:35; v/v) as...

The multivalent character of dendrimers has positioned these well-defined, highly branched macromolecules at the forefront in the development of new contrast agents for biomedical magnetic resonance imaging (MRI). By modifying the periphery of the dendrimer with gadolinium(III) chelates, the relaxivity of the resulting MRI contrast agent is increased considerably, compared to low molecular weig...

A simple labeling procedure of stem/progenitor cells based on the use of Gd-HPDO3A and Eu-HPDO3A, respectively, is described. The Gd-chelate acts as T(1)-agent for MRI visualization, whereas the corresponding Eu-chelate acts as reporter in fluorescence microscopy. Owing to their substantial chemical equivalence, the two chelates are equally internalized in EPCs (endothelial progenitor cells), t...

In the present study we have synthesized new trinuclear complexes of alkali metal salts with interaction of stable metal chelates of violuric Acid of Ni(II) & Cu(II) having general formula [Ma(H2Va)2.(MbL)2] and [Ma(H2Va)2.(MbX)2] where Ma=Ni (II) or Cu(II) and Mb =Li + , Na & K , H2Va= deprotonated Violuric Acid , L=deprotonated 1-nitroso-2-naphthol or 8-hydroxyquinoline and, X= ClO-4 or SCN ....