Ethylenebis dimethylphosphine

Ethylenebis(dimethylphosphine) is an air-sensitive, colorless liquid which boils at 180°/760 mm. specific gravity, O.9O43 d5, 1.4887. It inflames on contact with air but may be kept indefinitely in sealed ampuls under nitrogen. 

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Uranium. tetrakis(phenoxy)bis[ethylenebis-(dimethylphosphine)]-structure, 1,89... 

Ethoxytriethyldiphosphinyl oxide, 3094 Ethyldimethylphosphine, 1735 Ethylenebis(dimethylphosphine), 25 85 Ethylphosphine, 0949... 

Chlorophenylmagnesium bromide Magnesium, bromo(p-chloro-phenyl)- (8) Magnesium, bromo(4-chlorophenyl)- (9) (873-77-8) Ni(dmpe)Cl2 Nickel, dichloro[ethylenebis[dimethylphosphine]]-... 

Ethyl 2,3-diazidopropionate, 1897 Ethyl diazoacetate, 1499 Ethyl 4-diazo-l,2,3-triazole-5-carboxylate, 1847 Ethyl 3,4-dihydroxybenzenesulfonate, 2983 t Ethyldimethylamine, 1721 t 3-Ethyl-2,3-dimethylpentane, 3197 Ethyldimethylphosphine, 1729 1,2-Ethylenebis(ammonium) perchlorate, 0960 Ethylenebis(dimethylphosphine), 2581a 2,2 -(l,2-Ethylenebis)3-phenyloxaziridine, 3700 Ethylenediamine dinitrate, see 1,2-Diammonioethane nitrate, 0962a Ethylenediamine, see 1,2-Diaminoethane, 0949 Ethylene dibromide, see 1,2-Dibromoethane, 0781 Ethylenedicaesium, 0794... 

If the ultimate goal of the synthesis is ethylenebis(dimethylphosphine) (DMPE), an alternative synthesis4 based on ethylenebis(dichlorophosphine)5 is recommended. This alternative procedure is convenient and is being adapted for publication in Inorganic Syntheses. 

ETHYLENEBIS(DIMETHYLPHOSPHINE) [l,2-BIS(DIMETHYLPHOSPHINO)ETHANE], TETRAMETHYLDIPHOSPHANE DISULFIDE, AND TETRAMETHYLDIPHOSPHANE... 

Diphosphines are of considerable interest as ligands because of their excellent donor chelating properties with transition-metal ions, and are used to stabilize unusual oxidation states. Complexes formed with ethylenebis(dimethylphosphine) have increased electron density at the metal atom and are particularly reactive compared with the analogous ethylenebis(diphenylphosphine) complexes.1... 

The preparation of ethylenebis(dimethylphosphine) has been described by metallation of phosphine with sodium, followed by methylation of the resulting sodium phosphide with iodomethane. Two further metallation-methylation sequences using sodamide and iodomethane produce sodium dimethylphosphide, which is treated with 1,2-dichloroethane in liquid ammonia, to give the diphosphine.2 Other procedures involve heating tetramethyldiphosphane with ethylene,3 or tetramethyldiphosphane disulfide with ethylene, both... 

The present procedure starts with tetramethyldiphosphane disulfide which is desulfurized with iron powder to tetramethyldiphosphane. The diphosphane is cleaved with sodium in liquid ammonia, followed by addition of 1,2-dichloroethane, to give ethylenebis-(dimethylphosphine). This procedure avoids the use of phosphine (PH3) and eliminates the need for high-pressure apparatus. Sections A and B for preparing tetramethyldiphosphane and the disulfide have been reported5,6 and are reproduced with some modifications. The total working time for Secs. A, B, and C is 3 days. 

Caution. Dimethylphosphine, ifformed by traces of moisture, is evolved and may collect in vacuum-line traps or may disperse through the sewer system if a water aspirator is used.) The ethylenebis-(dimethylphosphine) distills at 65-66° at 10 torr yield is 13.5 g. (50%). 

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