The mechanism of Aβ aggregation in the absence of metal ions is well established, yet the role that Zn2+ and Cu2+, the two most studied metal ions, released during neurotransmission, paly in promoting Aβ aggregation in the vicinity of neuronal synapses remains elusive. Here we report the kinetics of Zn2+ binding to Aβ and Zn2+/Cu2+ binding to Aβ-Cu to form ternary complexes under near physiolog...

Methods of quantum chemistry have been applied to double-charged complexes involving the transition metals Ni(2+), Cu(2+) and Zn(2+) with the aromatic amino acids (AAA) phenylalanine, tyrosine and tryptophan. The effect of hydration on the relative stability and geometry of the individual species studied has been evaluated within the supermolecule approach. The interaction enthalpies, entropies...

Flow injection-solid phase spectrometry (FI-SPS) has been applied to the determination of cobalt(II) in water samples. The complex formed between cobalt and 5-Br-PADAB was on-line protonated and concentrated on an AG 50W-X2 cation-exchanger in a flow-through cell. The increase in absorbance caused by the accumulation of the complex in the resin was continuously measured. The interference by cop...

UV/TiO2 photocatalysis of chelated copper in aqueous solutions has been performed starting from Cu(II)-tartaric acid, Cu(II)-citric acid, Cu(II)-EDTA and Cu(II)-DTPA,in the presence of oxygen and at acidic pH. The photocatalytic reaction obeys first-order kinetic equation. The influence of Cu(II) on photocatalytic oxidation of organic ligands and how the various organics will affe...

The reaction of di-2-pyridyl ketone with copper dichloride dihydrate and tartaric acid in water afforded the title compound, [Cu(C(11)H(10)N(2)O(2))(2)]C(4)H(4)O(6). The Cu(II) atom lies on an inversion center N,O,N'-chelated by two di-2-pyridylmethane-diol ligands in a tetragonally distorted octa-hedral geometry. The tartrate anion is also located on an inversion center and has disordered hydr...

The crystal structure of the title compound, [Cu(NO(3))(C(21)H(14)ClN(3))(H(2)O)]NO(3)·[Cu(NO(3))(2)(C(21)H(14)ClN(3))]·H(2)O, con-sists of two crystallographically independent Cu(II) complexes, in which each copper cation is penta-coordinated by three N atoms of the chelating ligand and two O atoms of nitrate anions or water mol-ecules. One of the coordinated nitrate anions is disordered over ...

The mol-ecular structure of the title compound, [CuCl2(C11H20N2S)2], shows the Cu(II) atom with a distorted tetra-hedral geometry from two Cl atoms [Cu-Cl = 2.2182 (6) Å] and two thione S atoms [Cu-S = 2.3199 (6) Å]. The angles at the copper cation, which lies on a twofold rotation axis, are Cl-Cu-Cl = 142.84 (4)°, Cl-Cu-S = 94.80 (2) and 99.97 (2)°, and S-Cu-S = 132.46 (4)°. The planes of the ...

The title complex, [Cu(C(11)H(10)N(2)O(2))(2)](BF(4))(2)·2H(2)O, was isolated as a dihydrate from a 1:2 molar mixture of copper(II) tetra-fluoridoborate hexa-hydrate with di-2-pyridyl ketone in aqueous solution. The centrosymmetric complex cation is structurally similar to that found in previously reported salts and exhibits Cu-O bonds deviating by 25 degrees from an octa-hedral geometry by the...