1,2-Bis(dimethylphosphino)ethane (dmpe) is a diphosphine ligand in coordination chemistry. It is a colorless, air-sensitive liquid that is soluble in organic solvents. With the formula (CH2PMe2)2, dmpe is used as a compact strongly basic spectator ligand (Me = methyl), Representative complexes include V(dmpe)2(BH4)2, Mn(dmpe)2(AlH4)2, Tc(dmpe)2(CO)2Cl, and Ni(dmpe)Cl2.[2]
Synthesis
It is synthesised by the reaction of methylmagnesium iodide with 1,2-bis(dichlorophosphino)ethane:[3]
- Cl2PCH2CH2PCl2 + 4 MeMgI → Me2PCH2CH2PMe2 + 4 MgICl
Alternatively it can be generated by alkylation of sodium dimethylphosphide.
The synthesis of dmpe from thiophosphoryl chloride has led to serious accidents and has been abandoned.[4]
Related ligands
- Bis(dicyclohexylphosphino)ethane, a bulkier analogue, which is also a solid.
- 1,2-Bis(diphenylphosphino)ethane, more air-stable than dmpe, but less basic.
- 1,2-Bis(dimethylphosphino)benzene, a more rigid analogue of dmpe.
- Tetramethylethylenediamine, the diamine analogue of dmpe.
References
- ^ Sigma-Aldrich Co., 1,2-Bis(dimethylphosphino)ethane. Retrieved on 2013-07-20.
- ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
- ^ R. J. Burt; J. Chatt; W. Hussain; G. J. Leigh (1979). "A convenient synthesis of 1,2-bis(dichlorophosphino)ethane, 1,2-bis(dimethylphosphino)ethane and 1,2-bis(diethylphosphino)ethane". Journal of Organometallic Chemistry. 182 (2): 203–6. doi:10.1016/S0022-328X(00)94383-3.
- ^ Bercaw, J. E.; Parshall, G. W. (1985). "Preparation of Tetramethyldiphosphine Disulfide and Ethylenebis(Dimethylphosphine) (Dmpe)". Inorganic Syntheses. Vol. 23. pp. 199–200. doi:10.1002/9780470132548.ch42. ISBN 9780470132548.