Ethane-, copper

C49H440S8Zn4, catena-jn-Benzenethiolato-(methanol-benzenethiolato-hexa-/Li benzenethiolato)-tetra-zinc (II), 46B, 1236 C5 2H4 8Cl2Cu2P4S4f Di jLi-chior0 b 1 s[ jLi-1, 2-bis(diphenylphosphinothio-yl)ethane]copper(I), 45B, 1375... 

A small portion of vinyl chloride is produced from ethane via the Transcat process. In this process a combination of chlorination, oxychlo-rination, and dehydrochlorination reactions occur in a molten salt reactor. The reaction occurs over a copper oxychloride catalyst at a wide temperature range of 310-640°C. During the reaction, the copper oxychloride is converted to copper(I) and copper(II) chlorides, which are air oxidized to regenerate the catalyst. Figure 6-1 is a flow diagram of the Transcat process for producing vinyl chloride from ethane. ... 

In refrigerating systems, halogen derivatives of methane and ethane marketed under the trade names of Arctons and Freons are without action on pure aluminium and its copper-free alloys in dry conditions, but in wet conditions monochlorodi-, dichloromono-and trichloromonofluoromethanes can hydrolyse to produce slight attack on the aluminium. 

Similar structural changes of the copper layer on ruthenium are observed for the ethane hydrogenolysls reaction shown In Figure 10 (12). The effect of copper at low coverages Is to simply block active ruthenium sites on a one to one basis with three dimensional cluster growth occurring at roughly a third of a monolayer. 

Figure 10. Relative rate of ethane hydrogenolysls on a Ru(OOOl) catalyst as a function of copper coverage. Reaction temperature 5S0K. Sulfur poisoning data from Figure 8 have been replotted for comparison.

The proposed reaction mechanism involves intermolecular nucleophilic addition of the amido ligand to the olefin to produce a zwitterionic intermediate, followed by proton transfer to form a new copper amido complex. Reaction with additional amine (presnmably via coordination to Cn) yields the hydroamination prodnct and regenerates the original copper catalyst (Scheme 2.15). In addition to the NHC complexes 94 and 95, copper amido complexes with the chelating diphosphine l,2-bis-(di-tert-bntylphosphino)-ethane also catalyse the reaction [81, 82]. 

Fig. 6. Activities of copper-nickel alloy catalysts for the hydrogenolysis of ethane to methane and the dehydrogenation of cyclohexane to benzene. The activities refer to reaction rates at 316° C. Ethane hydrogenolysis activities were obtained at ethane and hydrogen pressures of 0.030 and 0.20 atm., respectively. Cyclohexane dehydrogenation activities were obtained at cyclohexane and hydrogen pressures of 0.17 and 0.83 atm, respectively (74).

Summary of Kinetic Parameters for Ethane Hydrogenolysis on Copper-Nickel Alloys (74)... 

The reaction of benzotriazoles with aryl halides catalyzed by a mixture of Pd(dppe)Cl2 (DPPE = bis-(diphenylphosphino)ethane) or Pd(dppf)Cl2, copper(I)iodide or copper(II)carboxylates, and a phase-transfer catalyst has been shown to proceed in good yield in DMF solvent.104 Both copper and palladium were required for these reactions to occur at the N-l position in high yields. Similar results for the coupling of amines with aryliodonium salts in aqueous solvent were observed.105... 

Apte and Gunn [23] used liquid-liquid extraction, involving 1 1 1 trichlor-ethane extraction of the ammonium pyrrolidine dithiocarbamates to concentrate copper, nickel, lead, and cadmium from estuary water. (Detection limits... 

The potential triple A D D D A A interaction between cytosine and bis(amidino-0-methylurea)ethane, when co-ordinated to copper(II), is shown in Scheme 12 (l.h.s.). Alternative complementary interactions between amidino-O-alkylureas and DNA pyrimidine bases include the double D A A-D interaction with thymine shown in Scheme 12 (r.h.s.). 

Finally, some organocopper compounds undergo charge disproportionation under the influence of ligands that bind strongly to copper. Treatment of mesityl-copper with l,2-bis-(diphenylphosphino)ethane (DPPE), for example, results in the formation of bis(mesityl)copper anions and a copper cation to which four phosphorus atoms of two DPPE molecules are coordinated [75]. 

Figure 5.18 In-situ STM images recorded in CUSO4/H2SO4 electrolyte of Cu UPD growth on Au(l 1 1) modified by two different types of thiols, (a) SAM of ethane thiol (250x250nm ) with a ramified structure and (b) SAM of MBP2 (600 x 600 nm ) with circular copper patches [43], Enlarged area reveals nanometer-sized islands protruding on patches, (a) Reproduced with permission from Ref [210].

A hydroxoaqua copper complex containing N, N, N, A -tetramethyl-1,2-diamino-ethane (250) is an excellent catalyst for the hydrolysis of sarin, O-isopropyl methylphosphonofluoridate (251), and diethyl p-nitrophenyl phosphate (252 R = Et). The mechanism of the reaction probably involves bound hydroxide attacking the phosphoryl group with concomitant electrophilic catalysis by copper. 

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