Search results for "COPP"
showing 10 items of 3147 documents
The oxamate route, a versatile post-functionalization for metal incorporation in MIL-101(Cr): Catalytic applications of Cu, Pd, and Au
2013
Abstract A new consecutive post-functionalization method has been developed for the inclusion of additional metal functionalities in Metal Organic Frameworks (MOFs) through oxamate as chelating agent. This may result in catalytic centers of metal–organic complexes or in controlled formation of metal nanoparticles, demonstrated for Cu, Pd and Au, in the highly stable MIL-101(Cr) framework. In a first post-synthesis step, reduction of the NO 2 -MIL-101(Cr) leads to the formation of NH 2 -MIL-101(Cr). The second functionalization consists of a straightforward condensation of the amino groups of the ligand with ethyl chloro-oxoacetate resulting in the formation of free oxamates attached to the …
Mo(CO)6 dissociation on Cu(111) stimulated by a Scanning Tunneling Microscope
2013
Abstract The surface of Cu(111) was exposed to molybdenum hexacarbonyl Mo(CO)6 with monolayer coverage at temperature 160 K and studied by a Scanning Tunneling Microscope. The monolayer structure has a hexagonal arrangement and forms a (√7 × √7) R19 superlattice on the copper (111) plane. Upon repeated scanning the monolayer is transformed into a (1 × 2) superstructure with 3-fold oriented domains. The domains of (1 × 2) superstructure can change orientation under scanning according to 3-fold surface symmetry. From analysis of the domain mobility, it follows that CO groups of carbonyl fragments are organized in the (1 × 2) superstructure conditioning the domain reorientation. The observed s…
Laser spectroscopy of gallium isotopes beyond N = 50
2012
The installation of an ion-beam cooler-buncher at the ISOLDE, CERN facility has provided increased sensitivity for collinear laser spectroscopy experiments. A migration of single-particle states in gallium and in copper isotopes has been investigated through extensive measurements of ground state and isomeric state hyperfine structures. Lying beyond the N = 50 shell closure, 82Ga is the most exotic nucleus in the region to have been studied by optical methods, and is reported here for the first time. ispartof: pages:012071-6 ispartof: Journal of Physics: Conference Series vol:381 issue:1 pages:012071-6 ispartof: Rutherford Centennial Conference on Nuclear Physics location:Manchester, UK dat…
Presentation of the DSIP method for study of recrystallization process in subsurface zone induced by sandblasting
2011
In the paper we demonstrate the application of the positron annihilation experimental technique based on the scan of the positron implantation profile for observation of the recrystallization process in the subsurface zone (SZ). The SZ was created in the copper sample whose surface was exposed to a sandblasting treatment and then annealed at different temperatures. Application of 68Ge/68Ga positron source allows us to scan the depth of c.a. 150 μm. It was found that recrystallization goes faster close to the surface than in deeper regions. The complete rebuilding of the microstructure takes place at temperature of 600 °C. Some changes in the defect structure begin at temperature of 300 °C.
The Lure of Katanga Copper : Tanganyika Concessions Limited and the Anatomy of Mining and Mine Exploration 1899–1906
2016
This article provides a rare opportunity to follow the inception of mining and mine exploration economy in the first years of the European presence in colonial Zambia and Katanga as seen through the eyes of prospectors and mining experts working for the London-based company Tanganyika Concessions Limited. It draws on company records as well as the personal records of the early company employees who worked in North Western Rhodesia and adjoining Katanga until 1906. The most thought-provoking documents include diaries, letters and photographs, which depict the organisation and processes of early mining work, modes of mine exploration, and relations within the first mining communities and betw…
Relationship between cobalt, copper and zinc content of soils and vegetables
1992
The relationship between cobalt, copper and zinc content of soils and the vegetables grown in them is discussed. Samples of soil and edible vegetables were taken from 15 different sites, corresponding to four agricultural areas exposed to different degrees of environmental pollution: high industrial and traffic, high industrial and urban, and low industrial and urban pollution. Elements were determined by atomic absorption spectroscopy. Variance analysis (ANOVA) was applied to cobalt, copper and zinc content of vegetables and soils in order to detect significant differences among soils of different areas and the vegetables grown there. The possible relationship between the heavy metal conte…
Modeling Tyrosinase and Catecholase Activity Using New m-Xylyl-Based Ligands with Bidentate Alkylamine Terminal Coordination
2012
Chemical model systems possessing the reactivity aspects of both tyrosinase and catechol oxidase are presented. Using two m-xylyl-based ligands providing bidentate alkylamine terminal coordination, 1,3-bis[(N,N-dimethylaminoethyl)aminomethyl]benzene (L(H,H)) and 1,3-bis[(N,N,N'-trimethylaminoethyl)aminomethyl]benzene (L(Me,Me)), four new dicopper(I) complexes, [Cu(I)(2)(L(H,H))(MeCN)(4)][ClO(4)](2) (1), [Cu(I)(2)(L(H,H))(PPh(3))(2)(MeCN)(2)][ClO(4)](2) (2), [Cu(I)(2)(L(Me,Me))(MeCN)(2)][ClO(4)](2) (3), and [Cu(I)(2)(L(Me,Me))(PPh(3))(2)][ClO(4)](2) (4), have been synthesized and characterized. Complex 2 has been structurally characterized. Reaction of the dicopper(I) complex 3(2+) with diox…
Response of soil bacterial community structure to successive perturbations of different types and intensities
2008
SummaryIn soil, genetic structure modifications of indigenousbacterial community consecutively to a severe stress(mercury contamination) were delayed when thecommunity was pre-exposed to various minor per-turbations (heat, copper and atrazine). Such minorperturbations induced transitory community struc-ture modifications leading to an increase of commu-nity stability towards a severe mercury stress. Theseresults illustrated well the short-term pre-adaptationprocess for bacterial community hypothesizing thatcommunity submitted to perturbations become moreresistant to withstand another stress. Compared with other environmental matrices of the bio-sphere, soils are considered as the main reservo…
Biosorption of copper by wine-relevant lactobacilli
2011
Must and wine may be contaminated with elevated copper concentrations by the use of fungicides or in course of the vinification process. Hitherto only a few practicable and harmless procedures exist to reduce an excess of copper from must and wine. For this reason we investigated the biosorption of copper by eight wine-relevant Lactobacillus species. Both, living and heat-inactivated cells revealed a significant degree of Cu adsorption. It was shown that Cu binding correlated positively with an increasing pH value of the environment. The highest binding capacity of the tested lactic acid bacteria was found for L. buchneri DSM 20057 with a maximum of 46.17 μg Cu bound per mg cell in deionize…
Metal complex-DNA binding: Insights from molecular dynamics and DFT/MM calculations.
2012
Molecular dynamics (MD) simulations, followed by density functional theory/molecular mechanics (DFT/MM) calculations, provided a detailed structure of the binding site between the cationic metallointercalator (dipyrido [3,2-a:2',3'-c]phenazine)(glycinato)copper(II), [Cu(gly)(dppz)](+), and the two dodeca-deoxynucleotide duplexes [dodeca(dG-dC)]2 and [dodeca(dA-dT)]2. Three simultaneous DNA binding types were detected in the fully optimized DFT/MM structures: 1) metal coordination through exocyclic oxygen atoms of nitrogen bases; 2) intercalation of the dppz chromophore between stacked Watson-Crick AT-AT and GC-GC bases; and 3) hydrogen bonding between the glycinato ligand and amine groups o…