Copper association with ethylene

The nucleophilicity of the organocuprate cluster derives mainly from the filled copper 3d orbital, in combination with the carbon orbital associated with bonding to copper. These orbitals for the TS for reaction with methyl bromide and ethylene oxide are shown in Figure 8.4. 

An extensive literature exists on the characterization and structure—activity correlation of industrial copper-alumina oxychlorination catalysts [95-120]. At least two different major copper species have been identified. At low concentrations of copper (below ca 5 %), a well-dispersed copper species in intimate interaction with the alumina surface is formed. This species has a very low oxychlorination activity. At higher concentrations, a second species, probably formed by the de-position/precipitation of the copper chloro complexes, is observed. The latter gives rise to the active sites during the oxychlorination reaction. On the basis of an FTIR study of the oxychlorination reaction Finocchio et al. [42] postulated the formation of surface copper chloride-ethylene r-complex intermediates (which lead eventually to EDC) and weakly adsorbed HCl during oxychlorination. Formate species associated with copper and probable precursors for formation of the oxides of carbon by combustion were also identified. 

Among the polymers which contain clear crystalline phases are poly(ethylene) and PTFE. Their properties, however, are very different from those usually associated with crystalline solids in particular, they tend to exhibit low rigidity and at ambient temperatures are soft and deformable rather than brittle. This is because, unlike say sodium chloride or copper sulphate, crystalline polymers include both amorphous and crystalline regions. 

After the first works on the copper-catalyzed aiylation of alkyl amines in the presence of ethylene glycol (2 equiv.) L15 [134] or diethylsalicylamide (5-20 mol%) L16 [135] as ligands, Buchwald reported in 2006 a room-temperature procedure for this type of reaction (Scheme 4). The condensation of primary or secondary alkyl amines [136, 137], and amino alcohols (selective N- versus O-arylation) with aryl iodides was performed at 25°C, thanks to the help of cheap 1,3-diket(Mie ligands L17 associated with Cul (5%). Harsher cmiditions (90°C) had to be applied from aryl bromides (Scheme 4). 

Initial adhesion tests were made with 3.5- X 1- X 0.064-inch specimens of aluminum (Aluminum Associates No. 2024) and cold-rolled steel (polished ASTM A-415). Later tests were made with strips of copper, chrome-coated steel (Weirton Steel Co.), and brass with molded nylon 66 bars and with Mylar 300A poly (ethylene terephthalate) film. Before use, the specimens were washed (scrubbed with a soft bristle brush) with a solution of Alconox detergent, rinsed with water, rinsed with acetone, and dried. 

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