1,2-Bis(diphenylphosphino)ethane (dppe) is an organophosphorus compound with the formula (PhPCH) (Ph = phenyl). It is a common symmetrical bidentate ligand in coordination chemistry. It is a white solid that is soluble in organic solvents.
Preparation The preparation of dppe entails the alkylation of NaP(C6H5)2 with 1,2-dichloroethane:Girolami, G.; Rauchfuss, T.; Angelici, R. Synthesis and Technique in Inorganic Chemistry, 3rd ed.; University Science Books: Sausalito, CA, 1999; pp. 85-92.
Reactions The reduction of dppe by lithium gives the disecondary phosphine:
Hydrolysis gives the bis(secondary phosphine).
Treatment of dppe with hydrogen peroxide produces the phosphine oxides .Encyclopedia of Reagents for Organic Synthesis 2001 John Wiley & Sons, Ltd Selective mono-oxidation of dppe can be achieved by benzylation followed by hydrolysis:
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)(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 Bis(diphenylphosphino)methane
References