The structure of copper(II) complexes formed with triethanolamine (TEA) core poly(amidoamine) (PAMAM) dendrimers from generation 0 (G0) to 4 (G4) were investigated by the electron paramagnetic resonance (EPR) technique and molecular simulations. Different square planar coordination modes were detected as a function of copper(II) concentration, whose dynamic evolution relates to the high structu...

Blue copper proteins (Type I) exhibit unusual spectral and chemical properties such as higher reduction potentials and small hyperfine coupling constants A|| in the EPR spectrum in comparison with other copper(II) complexes. Such unusual properties are justified partly by the tetralhedral geometry around the copper(II) site and partly by the CuN2S2 chromophores in which the soft S atoms coordin...

Two novel symmetrical bis!tetradentate Schi} base ligands\ H1L and H3L\ have been prepared from the condensation of N\N?!bis"2!aminopropyl#oxamide with pyridine!1!carbaldehyde and pyrrol!1!car! baldehyde\ respectively[ The ligands react with copper"II# nitrate in basic medium to yield the dinuclear complexes ðCu1LŁ"NO2#1 and ðCu1LŁ[ ðCu1LŁ"NO2#1 reacts with sodium azide to yield the neutral din...

Copper(II) complexes, containing aliphatic tripodal tetramine ligand, [Cu(trpn)(NH3)] 2+ (1), [Cu(tren)(NH3)] 2+ (2), [Cu(332)(NH3)] 2+ (3) and [Cu(322)(NH3)] 2+ (4) are optimized at B3LYP/ LANL2DZ and B3LYP/GEN levels of theory in gas phase (where (trpn), (tren), (332) and (322) are N(CH2CH2CH2NH2)3, N(CH2CH2NH2)3, N[(CH2CH2CH2NH2)2(CH2CH2NH2)] and N[(CH2CH2CH2NH2)(CH2CH2NH2)2], respectively)....

We have solved the single crystal structure to 1.2-A resolution of the Z-DNA sequence d(CGCGCG) soaked with copper(II) chloride. This structure allows us to elucidate the structural properties of copper in a model that mimics a physiologically relevant environment. A copper(II) cation was observed to form a covalent coordinate bond to N-7 of each guanine base along the hexamer duplex. The occur...

Bleaching of eumelanin has been studied in model systems consisting of synthetic dopa-melanin and various concentrations of hydrogen peroxide, molecular oxygen, and copper(II) ions at neutral and alkaline pH. The data show that at neutral pH, in the dark, metal-ion-free melanin is very resistant to oxidation by hydrogen peroxide. However, the rate of bleaching of melanin, induced by H2O2 is sig...

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 cu2+, cd2+, co2+, ni2+, zn2+ and pb2+ ions were evaluated by p...