Английская Википедия:1,2-Bis(diphenylphosphino)ethane

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1,2-Bis(diphenylphosphino)ethane (dppe) is an organophosphorus compound with the formula (PhШаблон:SubPCHШаблон:Sub)Шаблон:Sub (Ph = phenyl). It is a commonly used bidentate ligand in coordination chemistry. It is a white solid that is soluble in organic solvents.

Preparation

The preparation of dppe is by the alkylation of [[sodium diphenylphosphide|NaPPhШаблон:Sub]]:[1][2]

P(CШаблон:SubHШаблон:Sub)Шаблон:Sub + 2 Na → NaP(CШаблон:SubHШаблон:Sub)Шаблон:Sub + NaCШаблон:SubHШаблон:Sub

NaP(CШаблон:SubHШаблон:Sub)Шаблон:Sub, which is readily air-oxidized, is treated with 1,2-dichloroethane (ClCHШаблон:SubCHШаблон:SubCl) to give dppe:

2 NaP(CШаблон:SubHШаблон:Sub)Шаблон:Sub + ClCHШаблон:SubCHШаблон:SubCl → (CШаблон:SubHШаблон:Sub)Шаблон:SubPCHШаблон:SubCHШаблон:SubP(CШаблон:SubHШаблон:Sub)Шаблон:Sub + 2 NaCl

Reactions

The reduction of dppe by lithium to give PhHP(CHШаблон:Sub)Шаблон:SubPHPh has been reported.[3]

PhШаблон:SubP(CHШаблон:Sub)Шаблон:SubPPhШаблон:Sub + 4 Li → PhLiP(CHШаблон:Sub)Шаблон:SubPLiPh + 2 PhLi

Hydrolysis gives the bis(secondary phosphine):

PhLiP(CHШаблон:Sub)Шаблон:SubPLiPh + 2 PhLi + 4HШаблон:SubO → PhHP(CHШаблон:Sub)Шаблон:SubPHPh + 4 LiOH + 2 CШаблон:SubHШаблон:Sub
[[Image:HFeCl dppe 2.svg|thumb|left|The bis(dppe) complex [[Chlorobis(dppe)iron hydride|HFeCl(dppe)Шаблон:Sub]] is one of the most accessible transition metal hydrides.]]

Treatment of dppe with conventional oxidants such as hydrogen peroxide (HШаблон:SubOШаблон:Sub), aqueous bromine (BrШаблон:Sub), etc., produces dppeO in low yield (e.g., 13%) as a result of non-selective oxidation.[4] Selective mono-oxidation of dppe can be achieved by reaction with PhCHШаблон:SubBr to give dppeO. Шаблон:NumBlk Шаблон:NumBlk

Hydrogenation of dppe gives the ligand bis(dicyclohexylphosphino)ethane.

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)Шаблон:Sub(dppe)) and of bridging behavior.[5] The natural bite angle is 86°.[6]

Related compounds

References

Шаблон:Reflist

  1. Шаблон:Cite journal
  2. Girolami, G.; Rauchfuss, T.; Angelici, R. Synthesis and Technique in Inorganic Chemistry, 3rd ed.; University Science Books: Sausalito, CA, 1999; pp. 85-92. Шаблон:ISBN
  3. Шаблон:Cite journal
  4. Encyclopedia of Reagents for Organic Synthesis 2001 John Wiley & Sons, Ltd
  5. Cotton, F.A.; Wilkinson, G. Advanced Inorganic Chemistry: A Comprehensive Text, 4th ed.; Wiley-Interscience Publications: New York, NY, 1980; p.246. Шаблон:ISBN
  6. Шаблон:Cite journal