Copper, organometallic complexes

Precipitation is often applied to the removal of most metals from wastewater including zinc, cadmium, chromium, copper, fluoride, lead, manganese, and mercury. Also, certain anionic species can be removed by precipitation, such as phosphate, sulfate, and fluoride. Note that in some cases, organic compounds may form organometallic complexes with metals, which could inhibit precipitation. Cyanide and other ions in the wastewater may also complex with metals, making treatment by precipitation less efficient. A cutaway view of a rapid sand filter that is most often used in a municipal treatment plant is illustrated in Figure 4. The design features of this filter have been relied upon for more than 60 years in municipal applications. 

Organometallic complexes of copper, silver, and gold are ideal precursors for carbene complexes along with some C- and N-coordinated species. Their reactivity pattern, in particular in oxidative addition reactions, was the most comprehensively studied. 

Organometallic complexes of copper, nickel, and palladium have been used in indole syntheses from arenes. Most of the reactions proceed under relatively mild conditions and in some cases give rise to formation of the less common 2-substituted compounds.68 Good yields of such 2-substituted derivatives are formed in reactions of o-iodoarylamines with cuprous acetylides in dimethylformamide (Scheme 41 ).69 The efficiency of this type of... 

Similar to chemical vapor deposition, reactants or precursors for chemical vapor synthesis are volatile metal-organics, carbonyls, hydrides, chlorides, etc. delivered to the hot-wall reactor as a vapor. A typical laboratory reactor consists of a precursor delivery system, a reaction zone, a particle collector, and a pumping system. Modification of the precursor delivery system and the reaction zone allows synthesis of pure oxide, doped oxide, or multi-component nanoparticles. For example, copper nanoparticles can be prepared from copper acetylacetone complexes [70], while europium doped yttiria can be obtained from their organometallic precursors [71]. 

The trimerization of alkynes is a general and useful method for the preparation of aromatic compounds [152]. However, this method has serious limitations when three different alkynes are used, as numerous regioisomers may be formed. Taka-hashi and co-workers have reported the beginnings of a solution using zirconocy-clopentadienes prepared in situ from two different alkynes. Substituted arenes were obtained upon addition of a third alkyne to the organometallic complex in the presence of copper chloride [153] or a nickel complex [154], This approach is nevertheless limited by the fact that at least one of the alkynes must be symmetrical, and by... 

The organometallic complexes are quite various cobaltocene/bis(ethylaceto-acetato) copper (II) [366], CuCl or CuBr/bipyridyl [367, 368], cobaltoxime complex [369], reduced nickel/halide system [370], organoborane [371], ruthenium complex/trialkoxyaluminum system [372]. 

Coupling of the cyclobutadiene complex 88 [48] with the protected acetylene 89 furnished the tetrayne 90, copper-mediated coupling of which, after removal of its acetylenic trime-thylsilyl groups, yielded the organometallic complex 91 [49]. 1H NMR analysis of this... 

The copper must complex to the alkene and then transfer the alkyl group to the Sn2 position as it gathers in the chloride. This might well be the mechanism, though it is often difficult to draw precise mechanisms for organometallic reactions. 

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