novel collagen-based hydrogel nanocomposites were synthesized by graft copolymerization of acrylamide and maleic anhydrid in the presence of different amounts of montmorillonite, using methylenebisacrylamide (mba)and ammonium persulfate (aps) as crosslinker and initiator, respectively. the optimum amount of clay on the swelling properties of the samples was studied. it was found that the hydrog...

The compounds containing the complex ion or complex molecule in which central metal atom or ion is surrounded by a number of oppositely charged ions or molecules are known as co-ordination compounds [1], complex compound or simply complex. Coordination basically refers to the "coordinate covalent bonds" (dipolar bonds) between the ligands and the central atom in 1914, when first coordination co...

Strapped heterobimetallic Hg(II)/Tl(I) porphyrin complexes, with both metal ions bridged by the N-core in a dynamic way, undergo spontaneous Tl(I)-to-Tl(III) oxidation leading to a mono-Tl(III) complex and a mixed valence Tl(I)/Tl(III) bimetallic complex. It provides a new opportunity to tune metal ion translocations in bimetallic porphyrin systems.

The first rare earth metal terminal imido complex has been isolated and structurally characterized. The complex has an extremely short M-N bond length and a nearly linear M-N-C angle. DFT studies showed two p orbitals of N(imido) atom form two bonds with two d orbitals of rare earth metal ion.

Electron paramagnetic resonance (EPR) spectroscopy was used to examine changes in internal structure and dynamics of the hammerhead ribozyme upon metal ion induced folding, changes in pH, and the presence and absence of ribozyme inhibitors. A nitroxide spin-label was attached to nucleotide U7 of the HH16 catalytic core, and this modified ribozyme was observed to retain catalytic activity. U7 wa...

In this work we introduce a practical use of synthesized Schiff base metal complex in sensing application. A new perchlorate-selective electrode based on the complex N, N'-4-nitro-phenylmethanebis-(salicylaldiminato) copper (II) [CuL] as the membrane carrier was developed. The electrode exhibits a good  Nernstian slope of -55.0 ± 1.0 mV/decade and a linear range of  for perchlorate. The lim...

To systematically study the effects of the number of d electrons of the first transition metal ions (Fe, Co, Ni, Cu and Zn) on the formation and stability of metal flavonoid complexes, we took the quercetin/M2+ complex as a model system to investigate the structures and properties of these complexes. Based on considerable structural information obtained through ESI-MSn, all of the first transit...

The interaction of Pb and Zn with Al20 3 in aqueous solution was studied as a function of pH and metal ion concentration. Results indicated the complexation of metal ions by oxide surfaces is strongly pH dependent; the extent of adsorption is a function of pH with an abrupt change within approximately 2 pH units. The adsorption of Pb and Zn on aluminium oxide can be interpreted in terms of a sm...

A peptide has been designed so that its chelating affinity for one type of metal ion regulates its affinity for a second, different type of metal ion. The prochelator peptide (PCP), which is a fusion of motifs evocative of calcium loops and zinc fingers, forms a 1 : 2 Zn : peptide complex at pH 7.4 that increases its affinity for Zn 3-fold in the presence of Tb (log b2 from 13.8 to 14.3), while...

a binding study of nickel ions by a new recombinant human growth hormone (hgh), produced as an injected drug, has been done at 27˚c in nacl solution (50 mm) using an isothermal titration calorimetry. there is a set of three identical and non-interacting binding sites for nickel ions. the intrinsic dissociation equilibrium constant and the molar enthalpy of binding are 40 μm and -16.5 kj/mol, re...