Triphos

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Triphos
File:Triphos.png
style="background: #F8EABA; text-align: center;" colspan="2" | Identifiers
CAS number 22031-12-5
style="background: #F8EABA; text-align: center;" colspan="2" | Properties
Molecular formula C41H39P3
Molar mass 624.67 g/mol
Appearance white crystals
Melting point

99-102 °C

Solubility in water Insoluble
style="background: #F8EABA; text-align: center;" colspan="2" | 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 references

1,1,1-Tris(diphenylphosphinomethyl)ethane, also known as triphos, is an organophosphorus compound with the formula CH3C[CH2PPh2]3. An air sensitive white solid, triphos is a tridentate ligand in inorganic and organometallic chemistry.

Synthesis

Triphos is prepared by the reaction of sodium diphenylphosphide and CH3C(CH2Cl)3:[1]

3 Ph2PNa + CH3C(CH2Cl)3 → CH3C[CH2PPh2]3 + 3 NaCl

The required sodium diphenylphosphide is conveniently obtained by cleaving triphenylphosphine with sodium in liquid ammonia.

Coordination chemistry

Triphos forms complexes with many transition metals. It usually functions as a tripodal ligand that occupies three facial sites.[2] Triphos complexes often exhibit high thermal stability. Such 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)], provide model intermediates in the catalytic cycle for hydrogenation of alkenes.[4]

Triphos sometimes behaves as a bidentate-chelating ligand. Illustrative cases include fac-[Mn(CO)3Br(η2-triphos)] and [M(CO)42-triphos)],where M is Cr, Mo, or W. [2] Triphos serves 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]

References

  1. W. Hewertson and H. R. Watson (1962). "283. The preparation of di- and tri-tertiary phosphines". J. Chem. Soc.: 1490–1494. doi:10.1039/JR9620001490. 
  2. 2.0 2.1 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:10.1016/0022-328X(95)06025-R. 
  3. 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:10.1021/om9602264. 
  4. 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:10.1021/om00115a035. 
  5. 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:10.1016/S0020-1693(00)93540-0.