Copper frameworks

The key to the superconducting properties of these ceramics seems to be the presence of planes of copper and oxygen atoms bonded to one another. The significance of the other atoms in the lattice seems to be to provide a stmctural framework for the copper and oxygen atoms. Thus, in the superconducting compound YBa2Cu30, the substitution of other rare earths for yttrium resrrlts in little change in the properties of the material. 

Using 1,4,8,11-tetraazacyclotetradecane, the structure of complex (800) (distorted trigonal planar Cu-Cu 6.739 A) was determined. Reactivity with 02 was investigated to demonstrate the formation of trans-l,2-peroxo species.585 As part of their work with copper(I) complexes with 02, the structure of a dicopper(I) complex ((801) distorted tetrahedral 7.04 A), supported by macrocyclic ligand environment, was reported by Comba and co-workers. Tolman and co-workers structurally characterized a three-coordinate copper(I)-phenoxide complex (802) (planar T-shaped) that models the reduced form of GO.587 The copper(I) analogue [Cu(L)][CF3-SO3]-0.43MeOI I (803) of a copper(II) complex (534) was also reported to demonstrate the role of ligand framework conformability in CV /Cu1 redox potentials.434 Wilson and co-workers... 

Intramolecular cyclopropanation of 4-aryl-1 -diazo-2-butanones 240 allows construction of the bicyclo[5.3.0]decane framework 12). In a reaction sequence analogous to that described above for the intermolecular ketocarbenoid reaction, bicyclo-[5.3.0]deca-l,3,5-trien-8-ones 241 are formed. They rearrange to the conjugated isomers 242 at the high temperatures needed if the reaction is catalyzed by copper 2311 or CuCl 232), but can be isolated in excellent yield from the Rh2(OAc)4-promoted reaction which occurs at lower temperature 233... 

The CO-TPD technique together with DFT calculations were previously successfully used to characterize monovalent copper positions in Cu-ZSM-5 and Cu-Na-FER catalysts[4, 5]. Recently it was observed that the CO molecule can also form adsorption complexes, where the CO molecule is bonded between two extra-framework cations [6]. It is likely that the formation of similar species between the Cu+ and K+ ions can also occur. The presence of adsorption complexes on such heterogeneous dual cation site was evidenced by the FTIR experiments [7]. The formation of CO complexes on dual cation sites was not considered in our previous TPD models where three types of Cu+ sites were taken into account. 

In the closely related compound AgCuS, the sulfur atoms form a slightly distorted hexagonal close-packed array. The Cu+ ions are located in positions within this framework to form layers, while the Ag+ ions lie between the sulfur-copper layers. These Ag+ ions show a progressively greater anisotropic thermal motion as the temperature rises, until, above 93°C, they are essentially completely mobile, leading to extremely high silver ion conductivity. 

As some necessary meteorological data were unavailable, we employed two different techniques to estimate the element abundance in air. Reverse calculations, in the framework of the American program MEPAS, allowed us to find the concentration fields based on experimental and especially adapted meteorological data. The second technique included direct calculations in the framework of the Russian standardized program Ecologist, which took into account the actual chemical composition of copper-smelting production contaminants. Both techniques had some restrictions, mainly insufficient initial information on the sources of contaminants and limited possibilities of the analytical equipment used. 

Low-cost material programs include the European Union s 54 million sixth framework research program on nanotechnologies and nanosciences, knowledge-based multifunctional materials, new production processes and devices. In partnership with the European Space Agency (ESA), the 5-year project seeks to find catalysts less expensive than platinum, which is used widely in fuel cells. As an alternative to platinum, nickel, cobalt and copper alloys are a possible solution. 

In contrast to Bosman et al., who only found metal complexation in the periphery of polypropylene imine) dendrimers, Tomalia and co-workers reported on the incorporation of copper ions into the interior of PAMAM dendrimers judging from EPR and UV/Vis studies [220, 221]. Metal binding in the dendrimer interior has also been observed for dendrimers carrying multiple ligands for metal complexation within their framework such as crown-ethers [222, 223] (Cs(I)-complexes), piperazine [224] (Pd(II)- and Cu(II)-complexes) or triazocyclononane [225] (Cu(II)- and Ni(II)-complexes). In most cases addition of the metal-salt to the dendrimer led to the formation of 1 1 complexes. 

Petit C, Bandosz TJ. The synthesis and characterization of copper-based metal organic framework/graphite oxide composites, Carbon 2011, 49, 563-572. 

While no complete pattern-dependent model has been presented to date for copper CMP, one step forward is a model framework for pattern-... 

Copper ions are supported with atomic dispersion due to the ion-exchange properties of zeolites and are difficult to collect owing to the framework structure of zeolite. 

The above redox behaivor of copper ions in zeolites is very distinct from those on other supports or in aqueous solution and is a specific phenomenon observed only on the zeolite. Die copper (I) ion in zeolites is fairly stable, as mentioned above, whereas the copper(II) ion supported on silica gel is readily and directly reduced to copperfO). The difficulty of generating Cu in zeolites may prevent the formation of copper particles. This may be the reason why we need a zeolite framework structure and why silica gel is a poor support for reacti(Mi.26... 

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