Ultrafast transient absorption spectra in the deep to near UV range (212-384 nm) were measured for the [Cu(II)(MeOH)(5)Cl](+) complexes in methanol following 255-nm excitation of the complex into the ligand-to-metal charge-transfer excited state. The electronically excited complex undergoes sub-200 fs radiationless decay, predominantly via back electron transfer, to the hot electronic ground st...

To determine the efficiency of copper (Cu) supplementation, a feeding experiment was carried out with 240 day old broiler chicks (vencobb-100). Birds were divided into four dietary treatments: i) C no additives, ii) T1-75 mg inclusion of Cu/kg diet, iii) T2-150 mg inclusion of Cu/kg diet, iv) T3-250 mg inclusion of Cu/kg diet. The present study was carried out in the Department of Animal Physio...

At high levels, copper in grape mash can inhibit yeast activity and cause stuck fermentations. Wine yeast has limited tolerance of copper and can reduce copper levels in wine during fermentation. This study aimed to understand copper tolerance of wine yeast and establish the mechanism by which yeast decreases copper in the must during fermentation. Three strains of Saccharomyces cerevisiae (lab...

A pyrenyl-appended calix[2]triazole[2]arene displaying excellent selectivity for Cu(2+) over other metal ions in pyrenyl excimer emission changes was synthesized. The binding mode with Cu(2+) was supported through nuclear magnetic resonance (NMR) studies and density functional theory (DFT) calculations. Fluorescence imaging demonstrates that this new copper sensor is capable of detecting intrac...

The title dinuclear copper complex, [Cu(2)Br(4)(C(28)H(32)N(6))], is located on an inversion center. The unique Cu(II) ion is in a slightly distorted square-pyramidal environment in which the N atoms of a dipicolyl-amine group and a bromide ligand form the basal plane. The apical site is occupied by a second Br atom. While the Cu-N distances involving the pyridine N atoms are the same within ex...

Oxidation of functioning copper has restricted its applicability as a catalyst for commercially important epoxidation of propylene to form propylene oxide. Here, we report that steady-state selectivity in propylene epoxidation on copper (Cu) nanoparticles increases sharply when the catalyst is illuminated with visible light. The selectivity increase is accompanied by light-induced reduction of ...

Copper (I) occurs in a variety of systems of current interest. It is present in high-temperature supercon­ ductors, but in addition the complexes of Cu(I) are im portant reagents in synthetic organic chemistry, they have interesting photochemical properties, and Cu(I) is an essential constituent of a number of en­ zymes. Twenty years ago our knowledge of the chem­ istry of divalent copper, Cu (...

-A synthetic investi :ation ofcopper(II) ibuprofenate (lbup) addition compounds with 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen) and 2,9-dimethyl-l,10-phenanthroline (dmph) has led to the isolation of dinuclear adducts of the forms [Cu(Ibup)2(bpy)]z'4H20 (1) and [Cu(Ibup)2(phen)]2 (2) and a mononuclear adduct Cu(lbup)2(dmph) (3). Spectroscopic data for adducts 1 and 2 are consistent with ...

Although the genome of Escherichia coli K-12 encodes just a few copper-containing enzymes, this transition metal is critical for the bacterium to derive energy from oxygen reduction and to protect itself from injury (1). For example, the CuB site within cytochrome bo oxidase facilitates the flow of electrons from ubiquinol to oxygen during aerobic respiration. A putative copper-binding site wit...

The bifunctional nature of Cu-ALOx-on-carbon catalysts, used in the direct catalytic conversion of ethanol to ethyl acetate, prompted an examination of the dispersion of Cu on the composite catalyst. For this, the NzO-method of Osinga et al. for estimation of bare metallic copper surface on composite copper catalysts has been adapted for use on a gravimetric adsorption unit and Ohen applied to ...