Bis(diphenylphosphino)methane

1,1-bis(diphenylphosphino)methane
Names
	IUPAC name methylenebis(diphenylphosphane)
	Other names Methylenebis(diphenylphosphine); dppm
Identifiers
CAS Number	2071-20-7 ;
3D model (JSmol)	Interactive image;
ChEMBL	ChEMBL307780 ;
ChemSpider	67509 ;
ECHA InfoCard	100.016.541
CompTox Dashboard (EPA)	DTXSID10174766 ;
	InChI InChI=1S/C25H22P2/c1-5-13-22(14-6-1)26(23-15-7-2-8-16-23)21-27(24-17-9-3-10-18-24)25-19-11-4-12-20-25/h1-20H,21H2 Key: XGCDBGRZEKYHNV-UHFFFAOYSA-N ; InChI=1/C25H22P2/c1-5-13-22(14-6-1)26(23-15-7-2-8-16-23)21-27(24-17-9-3-10-18-24)25-19-11-4-12-20-25/h1-20H,21H2 Key: XGCDBGRZEKYHNV-UHFFFAOYAH;
	SMILES P(c1ccccc1)(c2ccccc2)CP(c3ccccc3)c4ccccc4;
Properties
Chemical formula	C25H22P2
Molar mass	384.39 g/mol
Appearance	White powder or crystalline powder
Melting point	118 to 122 °C (244 to 252 °F; 391 to 395 K)
Solubility in water	Insoluble in water
Hazards
Safety data sheet (SDS)	External MSDS
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

1,1-Bis(diphenylphosphino)methane (dppm), is an organophosphorus compound with the formula CH₂(PPh₂)₂. Dppm, a white, crystalline powder, is used in inorganic and organometallic chemistry as a ligand.^[1] It is more specifically a chelating ligand because it is a ligand that is attached to the central metals (the phosphorus) by bonds from two or more donor atoms.

Synthesis and reactivity

1,1-Bis(diphenylphosphino)methane was first prepared by the reaction of sodium diphenylphosphide (Ph₂PNa) with dichloromethane:^[2]

Ph₃P + 2 Na → Ph₂PNa + NaPh

2NaPPh₂ + CH₂Cl₂ → Ph₂PCH₂PPh₂ + 2 NaCl

The methylene group (CH₂) in dppm (and especially its complexes) are mildly acidic. The ligand can be oxidized to give the corresponding oxides and sulfides CH₂[P(E)Ph₂]₂ (E = O, S). The methylene group is even more acidic in these derivatives.

Coordination chemistry

As a chelating ligand, 1,1-bis(diphenylphosphino)methane forms a four-membered ring with the constituents MP₂C. The ligand promotes the formation of bimetallic complexes that feature five-membered M₂P₂C rings. In this way, dppm promotes the formation of bimetallic complexes. One such example is the dipalladium chloride, Pd₂Cl₂(dppm)₂. In this complex, the oxidation state for the Pd centres are I. Bis(diphenylphosphino)methane gives rise to a family of coordination compounds known as A-frame complexes.^[3]

Ball-and-stick model of [Pd₂Cl₂(dppm)₂].^[4]

References

^ Humphrey, Mark G.; Lee, Jeanne; Hockless, David C.R.; Skelton, Brian W.; White, Allan H. (1993). "Mixed-Metal Cluster Chemistry". Organometallics. 12 (3468): 3468. doi:10.1021/om00033a017.
^ W. Hewertson; H. R. Watson (1962). "The preparation of di- and tri-tertiary phosphines". J. Chem. Soc. 12: 1490–1494. doi:10.1039/JR9620001490. {{cite journal}}: Unknown parameter |last-author-amp= ignored (|name-list-style= suggested) (help)
^ Albéniz, Ana C.; Espinet, Pablo (2006). "Palladium: Inorganic & Coordination Chemistry". Encyclopedia of Inorganic Chemistry. Encyclopedia of Inorganic Chemistry. doi:10.1002/0470862106.ia178. ISBN 0-470-86078-2. {{cite encyclopedia}}: Unknown parameter |last-author-amp= ignored (|name-list-style= suggested) (help)
^ G. Besenyei; L. Párkányia; E. Gács-Baitza; B. R. James (January 2002). "Crystallographic characterization of the palladium(I) dimers, syn-Pd2Cl2(dppmMe)2 and Pd2Cl2(dppm)2; solution conformational behavior of syn- and anti-Pd2Cl2(dppmMe)2 and their (μ-Se) adducts [dppmMe=μ-1,1-bis(diphenylphosphino)ethane, and DPPM=μ-bis(diphenylphosphino)methane]". Inorg. Chim. Acta. 327 (1): 179–187. doi:10.1016/S0020-1693(01)00682-X.

[1] Humphrey, Mark G.; Lee, Jeanne; Hockless, David C.R.; Skelton, Brian W.; White, Allan H. (1993). "Mixed-Metal Cluster Chemistry". Organometallics. 12 (3468): 3468. doi:10.1021/om00033a017.

[2] W. Hewertson; H. R. Watson (1962). "The preparation of di- and tri-tertiary phosphines". J. Chem. Soc. 12: 1490–1494. doi:10.1039/JR9620001490. {{cite journal}}: Unknown parameter |last-author-amp= ignored (|name-list-style= suggested) (help)

[3] Albéniz, Ana C.; Espinet, Pablo (2006). "Palladium: Inorganic & Coordination Chemistry". Encyclopedia of Inorganic Chemistry. Encyclopedia of Inorganic Chemistry. doi:10.1002/0470862106.ia178. ISBN 0-470-86078-2. {{cite encyclopedia}}: Unknown parameter |last-author-amp= ignored (|name-list-style= suggested) (help)

[4] G. Besenyei; L. Párkányia; E. Gács-Baitza; B. R. James (January 2002). "Crystallographic characterization of the palladium(I) dimers, syn-Pd2Cl2(dppmMe)2 and Pd2Cl2(dppm)2; solution conformational behavior of syn- and anti-Pd2Cl2(dppmMe)2 and their (μ-Se) adducts [dppmMe=μ-1,1-bis(diphenylphosphino)ethane, and DPPM=μ-bis(diphenylphosphino)methane]". Inorg. Chim. Acta. 327 (1): 179–187. doi:10.1016/S0020-1693(01)00682-X.

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