View source for Chemistry: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<br />Diphos<br />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 [[Chemistry:Organophosphorus compound|organophosphorus compound]] with the formula (Ph{{sub|2}}PCH{{sub|2}}){{sub|2}} (Ph = phenyl). It is a commonly used [[Chemistry:Ligand|bidentate ligand]] in coordination chemistry. It is a white solid that is soluble in organic solvents.

==Preparation==
The preparation of dppe is by the [[Chemistry:Alkylation|alkylation]] of NaPPh{{sub|2}}:<ref>{{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}}</ref><ref>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}}</ref>
:P(C{{sub|6}}H{{sub|5}}){{sub|3}} + 2 Na → NaP(C{{sub|6}}H{{sub|5}}){{sub|2}} + NaC{{sub|6}}H{{sub|5}}
NaP(C{{sub|6}}H{{sub|5}}){{sub|2}}, which is readily air-oxidized, is treated with 1,2-dichloroethane (ClCH{{sub|2}}CH{{sub|2}}Cl) to give dppe:
:2 NaP(C{{sub|6}}H{{sub|5}}){{sub|2}} + ClCH{{sub|2}}CH{{sub|2}}Cl → (C{{sub|6}}H{{sub|5}}){{sub|2}}PCH{{sub|2}}CH{{sub|2}}P(C{{sub|6}}H{{sub|5}}){{sub|2}} + 2 NaCl

==Reactions==
The reduction of dppe by [[Chemistry:Lithium|lithium]] to give PhHP(CH{{sub|2}}){{sub|2}}PHPh has been reported.<ref>{{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}}</ref>
:Ph{{sub|2}}P(CH{{sub|2}}){{sub|2}}PPh{{sub|2}} + 4 Li → PhLiP(CH{{sub|2}}){{sub|2}}PLiPh + 2 PhLi
Hydrolysis gives the bis(secondary phosphine):
:PhLiP(CH{{sub|2}}){{sub|2}}PLiPh + 2 PhLi + 4H{{sub|2}}O → PhHP(CH{{sub|2}}){{sub|2}}PHPh + 4 LiOH + 2 C{{sub|6}}H{{sub|6}}
:[[Image:HFeCl dppe 2.svg|thumb|left|The bis(dppe) complex [[Chemistry:Chlorobis(dppe)iron hydride|HFeCl(dppe){{sub|2}}]] is one of the most accessible transition metal hydrides.]]

Treatment of dppe with conventional oxidants such as [[Chemistry:Hydrogen peroxide|hydrogen peroxide]] (H{{sub|2}}O{{sub|2}}), aqueous [[Chemistry:Bromine|bromine]] (Br{{sub|2}}), etc., produces dppeO in low yield (e.g., 13%) as a result of non-selective oxidation.<ref name="Encycl1">Encyclopedia of Reagents for Organic Synthesis 2001 John Wiley & Sons, Ltd</ref> Selective mono-oxidation of dppe can be achieved by reaction with PhCH{{sub|2}}Br to give dppeO.
{{NumBlk|:|Ph{{sub|2}}P(CH{{sub|2}}){{sub|2}}PPh{{sub|2}} + PhCH{{sub|2}}Br → Ph{{sub|2}}P(CH{{sub|2}}){{sub|2}}PPh{{sub|2}}(CH{{sub|2}}Ph){{sup|+}}Br{{sup|−}}|{{EquationRef|2.3.}}}}
{{NumBlk|:|Ph{{sub|2}}P(CH{{sub|2}}){{sub|2}}PPh{{sub|2}}(CH{{sub|2}}Ph){{sup|+}}Br{{sup|−}} + NaOH + H{{sub|2}}O → Ph{{sub|2}}P(CH{{sub|2}}){{sub|2}}P(O)Ph{{sub|2}}|{{EquationRef|2.4.}}}}

Hydrogenation of dppe gives the ligand [[Chemistry:Bis(dicyclohexylphosphino)ethane|bis(dicyclohexylphosphino)ethane]].

==Coordination complexes==
Many coordination complexes of dppe are known, and some are used as homogeneous catalysts.  Dppe is almost invariably [[Chemistry:Chelation|chelating]], although there are examples of monodentate (e.g., W(CO){{sub|5}}(dppe)) and of bridging behavior.<ref name="Cotton1">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}}</ref>  The natural [[Chemistry:Bite angle|bite angle]] is 86°.<ref name="vanLeeuwen">{{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}}</ref>

==Related compounds==
*[[Chemistry:1,2-Bis(dimethylphosphino)ethane|1,2-Bis(dimethylphosphino)ethane]]
*[[Chemistry:Bis(diphenylphosphino)methane|Bis(diphenylphosphino)methane]]

==References==
{{Reflist}}

{{DEFAULTSORT:Bisdiphenylphosphinoethane}}
[[Category:Chelating agents]]
[[Category:Phenyl compounds]]
[[Category:1,2-Ethanediyl compounds]]

{{Sourceattribution|1,2-Bis(diphenylphosphino)ethane}}