1,2-Bis(diphenylphosphino)ethane
{{Chembox
|Watchedfields = changed
|verifiedrevid = 477203175
|Name = 1,2-Bis(diphenylphosphino)ethane
|ImageFile = DPPE structure.svg
|ImageFile1 = Dppe-from-xtal-2001-3D-balls.png
|ImageName1 = dppe
|PIN = (Ethane-1,2-diyl)bis(diphenylphosphane)
|OtherNames = 1,2-Bis(diphenylphosphino)ethane
Diphos
Dppe
|Section1={{Chembox Identifiers
|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
|ChEBI_Ref = {{ebicite|correct|EBI}}
|ChEBI = 30669
|ChemSpiderID = 66873
|PubChem = 74267
|EC_number = 216-769-2
|UNII = KL33QE52I4
|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,21-22H2
|SMILES = P(c1ccccc1)(c2ccccc2)CCP(c3ccccc3)c4ccccc4
|InChIKey = QFMZQPDHXULLKC-UHFFFAOYAX
|SMILES1 = c1ccc(cc1)P(CCP(c2ccccc2)c3ccccc3)c4ccccc4
|ChEMBL_Ref = {{ebicite|correct|EBI}}
|ChEMBL = 68683
|Beilstein = 761261
|Gmelin = 9052
|StdInChI_Ref = {{stdinchicite|correct|chemspider}}
|StdInChI = 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,21-22H2
|StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
|StdInChIKey = QFMZQPDHXULLKC-UHFFFAOYSA-N
|CASNo_Ref = {{cascite|correct|CAS}}
|CASNo = 1663-45-2
}}
|Section2={{Chembox Properties
|Formula = C{{sub|26}}H{{sub|24}}P{{sub|2}}
|MolarMass = 398.42 g/mol
|MeltingPtC = 140 to 142
}}
|Section7 = {{Chembox Hazards
|GHSPictograms = {{GHS07}}{{GHS09}}
|GHSSignalWord = Warning
|HPhrases = {{H-phrases|302|315|319|332|335|410}}
|PPhrases = {{P-phrases|261|264|270|271|273|280|301+312|302+352|304+312|304+340|305+351+338|312|321|330|332+313|337+313|362|391|403+233|405|501}}
}}
}}
1,2-Bis(diphenylphosphino)ethane (dppe) is an organophosphorus compound with the formula (Ph{{sub|2}}PCH{{sub|2}}){{sub|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:{{cite journal | journal = J. Chem. Soc. | year = 1962 | pages = 1490–1494 | doi = 10.1039/JR9620001490 | title = 283. The preparation of di- and tri-tertiary phosphines | author = W. Hewertson and H. R. Watson}}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}}
:{{chem2|2 NaP(C6H5)2 + ClCH2CH2Cl -> (C6H5)2PCH2CH2P(C6H5)2 + 2 NaCl}}
Reactions
The reduction of dppe by lithium give the disecondary phosphine:{{cite journal
| author = Dogan, J.
|author2= Schulte, J.B.|author3= Swiegers, G.F.|author4= Wild, S.B.
| year = 2000
| title = Mechanism of Phosphorus-Carbon Bond Cleavage by Lithium in Tertiary Phosphines. An Optimized Synthesis of 1, 2-Bis (phenylphosphino) ethane
| journal = J. Org. Chem.
| volume = 65
| issue = 4
| pages = 951–957
| doi = 10.1021/jo9907336
|pmid= 10814038}}
:{{chem2|(C6H5)2PCH2CH2P(C6H5)2 4 Li -> Li(C6H5)PCH2CH2P(C6H5)Li + 2 C6H5Li}}
Hydrolysis gives the bis(secondary phosphine).
:{{chem2|Li(C6H5)PCH2CH2P(C6H5)Li + 2 H2O -> H(C6H5)PCH2CH2P(C6H5)H + 2 LiOH}}
:Image:HFeCl dppe 2.svg is one of the most accessible transition metal hydrides.]]
Treatment of dppe with hydrogen peroxide produces the phosphine oxides {{chem2|(C6H5)2P(O)CH2CH2P(C6H5)2 and (C6H5)2P(O)CH2CH2P(O)(C6H5)2}}.Encyclopedia of Reagents for Organic Synthesis 2001 John Wiley & Sons, Ltd Selective mono-oxidation of dppe can be achieved by benzylation followed by hydrolysis:
:{{chem2|(C6H5)2PCH2CH2P(C6H5)2 + C6H5CH2Br -> (C6H5)2PCH2CH2P(C6H5)2(CH2C6H5)]Br}}
:{{chem2|(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){{sub|5}}(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. {{ISBN|0-471-02775-8}} The natural bite angle is 86°.{{cite journal |last1=Birkholz (née Gensow) |first1=Mandy-Nicole |last2=Freixa |first2=Zoraida |last3=van Leeuwen |first3=Piet W. N. M. |title=Bite angle effects of diphosphines in C–C and C–X bond forming cross coupling reactions |journal=Chemical Society Reviews |date=2009 |volume=38 |issue=4 |pages=1099–1118 |doi=10.1039/B806211K |pmid=19421583}}
Related compounds
References
{{Reflist}}
{{DEFAULTSORT:Bisdiphenylphosphinoethane}}