Triphos
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| Triphos | |
|---|---|
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| IUPAC name | 1,1,1-Tris(diphenylphosphinomethyl)ethane |
| Other names | Triphos, tdppme, tdme |
| Identifiers | |
| CAS number | [22031-12-5] |
| Properties | |
| Molecular formula | C41H39P3 |
| Molar mass | 624.67 g/mol |
| Appearance | white crystals |
| Melting point |
99-102 °C |
| Solubility in water | Insoluble |
| Hazards | |
| S-phrases | 22-24/25 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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1,1,1-Tris(diphenylphosphinomethyl)ethane, also known as triphos, is an organophosphorus compound with the formula CH3C[CH2PPh2]3. Triphos, an air sensitive white solid, is a widely used tridentate ligand in inorganic and organometallic chemistry.
Contents |
[edit] Synthesis
Triphos is prepared by the reaction of sodium diphenylphosphide (Ph2PNa) and CH3C(CH2Cl)3:[1]
- Ph3P + 2 Na → Ph2PNa + NaPh
- Ph2PNa + CH3C(CH2Cl)3 → CH3C[CH2PPh2]3
The required sodium diphenylphosphide is conveniently obtained by cleaving triphenylphosphine with sodium in liquid ammonia, treating it with water, and then extracting it with ether.
[edit] Coordination Properties
[edit] Facial Coordination
Triphos forms complexes with many transition metals. It usually serves as a tripodal ligand that occupies three facial sites. [2] Triphos confers high thermal stability to its complexes, thus triphos-metal complexes are used to analyze mechanistic aspects of homogenous catalysts.[3] For example, rhodium forms complexes with CH3C[CH2PPh2]3 like [(triphos)RhCl(C2H4)], [(triphos)RhH(C2H4)], and [(triphos)Rh(C2H5)(C2H4)], which are steps in a catalytic cycle for hydrogenation of alkenes, alkynes, and organic nitriles.[4]
[edit] Non-Facial Coordination
Triphos sometimes acts as a bidentate-chelating ligand. Illustrative cases include fac-[Mn(CO)3Br(ɳ2-triphos)] and [M(CO)4(ɳ2-triphos)],where M is Cr, Mo, or W. [2] Triphos acts as a tridentate-bridging ligand in an icosohedral Au13 cluster. The phosphine bridges three chlorogold(I) groups to form the tripod molecule of trichloro-1,1,1-(diphenylphosphinomethyl)ethanetrigold(I), CH3C[CH2PPh2AuCl]3. [5]
[edit] References
- ^ W. Hewertson and H. R. Watson (1962). "283. The preparation of di- and tri-tertiary phosphines". J. Chem. Soc.: 1490–1494. doi:.
- ^ a b Fernández, Eduardo J.; Gimeno, M. Concepción; Laguna, Antonio; Laguna, Mariano; López-de-Luzuriaga, José M.; & Olmos, Elena (1996). "Different Coordination modes of 1,1,1-tris(diphenylphosphinomethyl) ethane Ligand in Gold(I) and Gold(III) Complexes". Journal of Organometallic Chemistry 514: 169. doi:.
- ^ Bianchini, Claudio; Marchi, Andrea; Marvelli, Lorenza; Peruzzini, Maurizio; Romerosa, Antonio; Rossi, Roberto (1996). "Multiple Re-C Bonds at the [{MeC(CH2PPh2)3}Re(CO)2]+ Auxiliary". Organometallics 15: 3804. doi:.
- ^ Bianchini, Claudio; Meli, Andrea; Peruzzini, Maurizio; Vizza, Francesco (1990). "Tripodal Polyphosphine Ligands in Homogeneous Catalysis. 1. Hydrogenation and Hydroformylation of Alkynes and Alkenes Assisted by Organorhodium Complexes with [{MeC(CH2PPh2)3}Re(CO)2]". Organometallics 9: 226. doi:.
- ^ Cooper, Mervyn K.; Henrick, Kim; McPartlin, Mary; & Latten, Jozef L. (1982). "The synthesis and X-ray structure of trichloro-1,1,1-(diphenylphosphinomethyl)ethanetrigold(I)". Inorganica Chimica Acta 65: L185. doi:.
