Ethanediylbis diphenylphosphine Complexes of Iron

Fe(CH2CH2)[(C6Hs)2PCH2CH2P(C6H5)]2 + 3 Al(OC2HsXCsH702)C2H5 + 

Alternatively, the mixture may be decomposed by the careful, dropwise addition of 200 mL ethanol to the cooled, stirred solution (much gas is evolved), followed by the cautious addition of water. The yield of unrecrystallized product is 85 g (80%). 

2-ethanediylbis(diphenylphosphine)](ethylene)iron is a brick-red powder which is mildly air sensitive and should be stored and used in an inert atmosphere. The complex is only slightly soluble in diethyl ether and more soluble in aromatic solvents and tetrahydrofuran. The 31P 1H nmr spectrum consists of an A2B2 spin system 5a = 94.5 5b = 78.1 ppm, Jab = 40 Hz. 

The analogous diphosphine complex can be prepared with methylenebis(di-phenylphosphine) but not with 1,3-propanediylbis(diphenylphosphine). 

2-[2-DIPHENYLPHOSPHINO)ETHYL] PHENYLPHOSPHIN0 PHEN YL-CfPi 1 ETHANEDIYLBIS(DIPHENYLPHOSPHINE)] HYDRIDOIRON 

Bis((l,2-ethanediylbis(diphenylphosphine)](ethene)iron (17.6 g, 20 mmole) is suspended in toluene (120 mL) in a three-necked, 250-mL flask equipped with a nitrogen bubbler, reflux condenser, and magnetic stirring bar. The mixture is brought to reflux and maintained at this temperature for 20 minutes. The solution lightens slightly over this time as ethylene is evolved. The hot mixture is filtered and then cooled to room temperature. The volume of solvent is reduced under vacuum to about 25 mL. Pentane (80 mL) is added slowly, and the resultant orange solids are collected by vacuum filtration and washed with 

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