Diethyl cadmium

SYNS CADMIUM DIETHYL DirmOCARBAMATE ETHYL CADMATE ETHYL TUADS... 

CADMIUM DIAZIDE see CAD350 CADMIUM DIBROMIDE see CAD600 CADMIUM DICHLORIDE see CAE250 CADMIUM DICYANIDE see CAF500 CADMIUM DIETHYL DITHIOCARBAMATE see BJB500... 

Cadmium diethyl, 90 per cent. cadmium di-n-propyl, 85 per cent. cadmium di-n-butyl, 70 per cent. cadmium di-isobutyl, 75 per cent. cadmium di-isoamyl, 55 per cent. 

Cadrainm. Heat at 100- 130 C. Cadmium diethyl (not free from mercury). Frankland and Duppa, Tran Chem. Soc., 1864, 17, Annalen, 1S64, 130, 117. 

Cadmium dimethyl. Cadmium diethyl Cadmium di-n-propyl Cadmium di-u-butyl Cadmium di-isoamyl Cadmium di-isobutyl... 

Diethyl l,l-difluoro-2-alkenyIphosphonates have recently been synthesized in moderate yields (23-62%) through a copper(I)-catalyzed addition of zinc" or cadmium diethyl difluoromethylphosphonate to terminal" or perfluorinated internal acetylenes in DMF. 

The lead which separates may be fully utilized in the synthesis of tetraethyllead by adding an organocadmium compound and ethyl iodide to the reaction mixture. The essential step in this multistage process clearly is ethylation of lead by cadmium diethyl ... 

CdEC Cadmium diethyl dithiocarbamate ETHYL CADMATE ... 

Similarly, triphenyltin hydride reacts with diethylzinc or diethyl-cadmium in a strongly solvating solvent, such as oxolane (tetrahydro-furan) or 1,2-dimethoxyethane, to give the solvated, metal-metal-bonded products (272). 

Rodionova and Ivanov [667] used chelate extraction in the determination of copper, bismuth, lead, cadmium, and zinc in seawater. The metal complexes of diethyl and dithiophosphates are extracted in carbon tetrachloride prior to determination by atomic absorption spectrometry. 

Di-n-butylcadmium was prepared by the rapid addition of cadmium chloride (50.4 g, 0.275 mol) to a cooled solution of n-butylmagnesium bromide formed from magnesium (12.15 g, 0.50 mol) and n-butyl bromide (75.4 g, 0.55 mol) in anhydrous diethyl ether (550 ml). Following the addition, the reaction mixture was stirred at 0°C for 2 h. The di-n-butylcadmium reaction mixture, including the precipitate, was then added to a stirred solution of phosphorus trichloride (85.9 g,... 

Block, M. and Part, P. (1986). Increased availability of cadmium to perfused rainbow trout (Salmo gairdneri, Rich) gills in the presence of the complexing agents diethyl dithiocarbamate, ethyl xanthate and isopropyl xanthate, Aquat. Toxicol., 8, 295-302. 

Drying, usually by physical methods, is one of the most common unit operations in both laboratory or industrial scale process chemistry, and since heating is usually employed to remove volatiles, thermally unstable materials may decompose if overheated. As a light-hearted example, when a faulty oven thermostat led to overheating of mercuric thiocyanate, a monstrous Pharaoh s serpent resulted. Drying moist cadmium propionate in an electric oven led to explosive ignition of the diethyl ketone vapour produced as an unforeseen by-product. Drying 3,5-dinitro-2-toluamide had more serious consequences. 

One of the first examples of addition of a zinc enolate to an alkyne was a report dealing with the zinc or cadmium stearate-catalyzed addition of substituted malonates to acetylene under pressure250. Later, Schultze described the intermolecular nucleophilic addition of the zinc enolate derived from diethyl bromomalonate to phenylacetylene in refluxing xylene leading to the alkylidene malonate 392 (equation 171)251. 

Dialkoxyphosphinydifluoromethyl cadmium reagent can be readily prepared via reaction of diethyl bromodifluoromethylphosphonate with acid-washed cadmium powder [270] (Scheme 93). This cadmium reagent exhibits remarkable stability and versatile chemical reactivity. Typical examples are outlined below [271-273] (Scheme 93). 

Many organocadmium compounds are known but few have been of commercial importance. Wanklyn first isolated diethyl cadmium in 1856. The properties of this and other dialkylcadmiums are listed in Table 4. In general, these materials are prepared by reaction of an anhydrous cadmium halide with a Grignard or alkyUithium reagent followed by distillation of the volatile material in an inert atmosphere or in vacuo. Only the liquid dimethyl compound is reasonably stable and then only when stored in a sealed tube. Dimethylcadmium is mildly pyrophoric in air and produces dense clouds of white, then brown, cadmium oxide smoke, which is highly toxic if breathed (45). When dropped into water, the liquid sinks in large droplets that decompose with a series of small explosive jerks and pops. For this reason, and particularly because of the low thermal stability, most dialkylcadmium materials are prepared and used in situ without separation, eg, in the conversion of acid chlorides to speciality ketones (qv) ... 

Many dialkyl and diaryl cadmium compounds have found use as polymerization catalysts. For example, the diethyl compound catalyzes polymerization of vinyl chloride, vinyl acetate, and methyl methacrylate (45), and when mixed with TiCl can be used to produce polyethylene and crystalline polypropylene for filaments, textiles, glues, and coatings (45). With >50% TiCl diethyl cadmium polymerizes dienes. Diethyl cadmium maybe used as an intermediate ethylating agent in the production of tetraethyllead. The diaryl compounds such as diphenylcadmium [2674-04-6]> (C H Cd, (mp 174°C) are also polymerization catalysts. These compounds are also prepared using Grignard or arylUthium reagents in tetrahydrofiiran (THF) solvent but may be prepared by direct metal substitution reactions such as ... 

Pyrrole- and indole-carboxylic acid chlorides react with dialkyl- and diaryl-cadmium to yield the ketones and it is noteworthy that the reaction of the anhydride of indole-2,3-dicarboxylic acid with diphenylcadmium produces 3-benzoylindole-2-carboxylic acid and not its isomer (53JCS1889). The ability of l-methylindole-2-carboxylic acid to react with nucleophiles is enhanced by conversion into the mixed anhydride with methanesulfonic acid. The mixed anhydride reacts with carbanions derived from diethyl malonate and from methyl acetate to yield the indolyl (3- keto esters (80TL1957). 

Both 1 1 and 2 1 complexes of Af,.ZV-diethyl- and N,iV-dimethyl-thiourea with zinc, cadmium and mercury halides have been prepared. The 2 1 complexes are either monomeric and tetrahedral or polymeric and halogen-bridged with octahedral metal coordination the 1 1 complexes also possess a polymeric, halogen-bridged structure, but with tetrahedral metal coordination.894 5... 

General caution and safety. The metal alkyls trimethylaluminum, trimethylgallium, trimethylindium, triethylindium, dimethylzinc, and diethyl-zinc all spontaneously inflame in air (pyrophoric) and are violently reactive toward water and carbon dioxide. Dimethylcadmium fumes upon exposure to air but does not inflame, and decomposes, sluggishly, in water. As with cadmium dichloride, and in common with all cadmium compounds, dimethylcadmium is extremely toxic. A dry powder extinguisher, sand bucket, and fire blanket should be at hand at all times. 

The remaining diethyl ether is fractionally distilled off from the dimethyl-cadmium at atmospheric pressue (bp 34-35°C). Distillation is continued until pure dimethylcadmium has started to cross the still head (bp 105-106°C)—at which point the argon flow through the paraffin-oil bubbler is increased to a rapid purge while the oil bath is lowered quickly to prevent distillation of further product. The system is allowed to stand for several minutes to allow any dimethylcadmium in the Vigreux column to drain back down into the distillation flask and valve D is then closed. A small amount of dimethylcadmium will decompose during this distillation process, as witnessed by the cadmium metal residue formed in the distillation flask, but this is unavoidable and does not significantly affect the subsequent yield of product. 

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