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1,2-Bis(diphenylphosphino)ethane

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1,2-Bis(diphenylphosphino)ethane
dppe
Names
Preferred IUPAC name (Ethane-1,2-diyl)bis(diphenylphosphane)
Other names 1,2-Bis(diphenylphosphino)ethane
Diphos
Dppe
Identifiers
CAS Number
3D model (JSmol)
Beilstein Reference 761261
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.015.246 Edit this at Wikidata
EC Number
  • 216-769-2
Gmelin Reference 9052
PubChem CID
UNII
CompTox Dashboard (EPA)
InChI
  • InChI=1S/C26H24P2/c1-5-13-23(14-6-1)27(24-15-7-2-8-16-24)21-22-28(25-17-9-3-10-18-25)26-19-11-4-12-20-26/h1-20H,21-22H2Key: QFMZQPDHXULLKC-UHFFFAOYSA-N
  • InChI=1/C26H24P2/c1-5-13-23(14-6-1)27(24-15-7-2-8-16-24)21-22-28(25-17-9-3-10-18-25)26-19-11-4-12-20-26/h1-20H,21-22H2Key: QFMZQPDHXULLKC-UHFFFAOYAX
SMILES
  • P(c1ccccc1)(c2ccccc2)CCP(c3ccccc3)c4ccccc4
  • c1ccc(cc1)P(CCP(c2ccccc2)c3ccccc3)c4ccccc4
Properties
Chemical formula C26H24P2
Molar mass 398.42 g/mol
Melting point 140 to 142 °C (284 to 288 °F; 413 to 415 K)
Hazards
GHS labelling:
Pictograms GHS07: Exclamation markGHS09: Environmental hazard
Signal word Warning
Hazard statements H302, H315, H319, H332, H335, H410
Precautionary statements P261, P264, P270, P271, P273, P280, P301+P312, P302+P352, P304+P312, P304+P340, P305+P351+P338, P312, P321, P330, P332+P313, P337+P313, P362, P391, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). checkY verify (what is  ?) Infobox references
Chemical compound

1,2-Bis(diphenylphosphino)ethane (dppe) is an organophosphorus compound with the formula (Ph2PCH2)2 (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:

2 NaP(C6H5)2 + ClCH2CH2Cl → (C6H5)2PCH2CH2P(C6H5)2 + 2 NaCl

Reactions

The reduction of dppe by lithium give the disecondary phosphine:

(C6H5)2PCH2CH2P(C6H5)2 4 Li → Li(C6H5)PCH2CH2P(C6H5)Li + 2 C6H5Li

Hydrolysis gives the bis(secondary phosphine).

Li(C6H5)PCH2CH2P(C6H5)Li + 2 H2O → H(C6H5)PCH2CH2P(C6H5)H + 2 LiOH
The bis(dppe) complex HFeCl(dppe)2 is one of the most accessible transition metal hydrides.

Treatment of dppe with hydrogen peroxide produces the phosphine oxides (C6H5)2P(O)CH2CH2P(C6H5)2 and (C6H5)2P(O)CH2CH2P(O)(C6H5)2. Selective mono-oxidation of dppe can be achieved by benzylation followed by hydrolysis:

(C6H5)2PCH2CH2P(C6H5)2 + C6H5CH2Br → (C6H5)2PCH2CH2P(C6H5)2(CH2C6H5)]Br
(C6H5)2PCH2CH2P(C6H5)2(CH2C6H5)]Br + NaOH → (C6H5)2PCH2CH2P(O)(C6H5)2 + C6H5CH3 + NaBr

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)5(dppe)) and of bridging behavior. The natural bite angle is 86°.

Related compounds

References

  1. W. Hewertson and H. R. Watson (1962). "283. The preparation of di- and tri-tertiary phosphines". J. Chem. Soc.: 1490–1494. doi:10.1039/JR9620001490.
  2. Girolami, G.; Rauchfuss, T.; Angelici, R. Synthesis and Technique in Inorganic Chemistry, 3rd ed.; University Science Books: Sausalito, CA, 1999; pp. 85-92. ISBN 0-935702-48-2
  3. Dogan, J.; Schulte, J.B.; Swiegers, G.F.; Wild, S.B. (2000). "Mechanism of Phosphorus-Carbon Bond Cleavage by Lithium in Tertiary Phosphines. An Optimized Synthesis of 1, 2-Bis (phenylphosphino) ethane". J. Org. Chem. 65 (4): 951–957. doi:10.1021/jo9907336. PMID 10814038.
  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. ISBN 0-471-02775-8
  6. Birkholz (née Gensow), Mandy-Nicole; Freixa, Zoraida; van Leeuwen, Piet W. N. M. (2009). "Bite angle effects of diphosphines in C–C and C–X bond forming cross coupling reactions". Chemical Society Reviews. 38 (4): 1099–1118. doi:10.1039/B806211K. PMID 19421583.
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