1,2-Bis(diphenylphosphino)ethane (dppe) is an

organophosphorus compound Organophosphorus compounds are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. Some organophosphorus compounds are highly effective i ...

with the formula (PhPCH) (Ph =

phenyl In organic chemistry, the phenyl group, or phenyl ring, is a cyclic group of atoms with the formula C6 H5, and is often represented by the symbol Ph. Phenyl group is closely related to benzene and can be viewed as a benzene ring, minus a hydrogen ...

). It is a commonly used

bidentate ligand In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electro ...

coordination chemistry A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Man ...

. It is a white solid that is soluble in organic solvents.

Preparation

The preparation of dppe is by the

alkylation Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effectin ...

of NaPPh: :P(CH) + 2 Na → NaP(CH) + NaCH NaP(CH), which is readily air-oxidized, is treated with

1,2-dichloroethane The chemical compound 1,2-dichloroethane, commonly known as ethylene dichloride (EDC), is a chlorinated hydrocarbon. It is a colourless liquid with a chloroform-like odour. The most common use of 1,2-dichloroethane is in the production of vin ...

(ClCHCHCl) to give dppe: :2 NaP(CH) + ClCHCHCl → (CH)PCHCHP(CH) + 2 NaCl

Reactions

The reduction of dppe by

lithium Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense soli ...

to give PhHP(CH)PHPh has been reported. :PhP(CH)PPh + 4 Li → PhLiP(CH)PLiPh + 2 PhLi Hydrolysis gives the bis(secondary phosphine): :PhLiP(CH)PLiPh + 2 PhLi + 4HO → PhHP(CH)PHPh + 4 LiOH + 2 CH : Treatment of dppe with conventional oxidants such as

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3 ...

(HO), aqueous

bromine Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest element in group 17 of the periodic table ( halogens) and is a volatile red-brown liquid at room temperature that evaporates readily to form a simi ...

(Br), etc., produces dppeO in low yield (e.g., 13%) as a result of non-selective oxidation.Encyclopedia of Reagents for Organic Synthesis 2001 John Wiley & Sons, Ltd Selective mono-oxidation of dppe can be achieved by reaction with PhCHBr to give dppeO. Hydrogenation of dppe gives the ligand

bis(dicyclohexylphosphino)ethane Bis(dicyclohexylphosphino)ethane, abbreviated dcpe, is an organophosphorus compound with the formula (C6H11)2PCH2CH2P(C6H11)2. It is a white solid that is soluble in nonpolar organic solvents. The compound is used as a bulky and highly basic d ...

Coordination complexes

Many coordination complexes of dppe are known, and some are used as homogeneous catalysts. Dppe is almost invariably chelating, although there are examples of monodentate (e.g., W(CO)(dppe)) and of bridging behavior.Cotton, F.A.; Wilkinson, G. ''Advanced Inorganic Chemistry: A Comprehensive Text'', 4th ed.; Wiley-Interscience Publications: New York, NY, 1980; p.246. The natural bite angle is 86°.

Related compounds

1,2-Bis(dimethylphosphino)ethane 1,2-Bis(dimethylphosphino)ethane (dmpe) is a diphosphine ligand in coordination chemistry. It is a colorless, air-sensitive liquid that is soluble in organic solvents. With the formula (CHPMe), dmpe is used as a compact strongly basic spectator ...

* Bis(diphenylphosphino)methane

References

{{DEFAULTSORT:Bisdiphenylphosphinoethane Chelating agents Diphosphines Phenyl compounds 1,2-Ethanediyl compounds