Triphos

Triphos
IUPAC name Bis(diphenylphosphinoethyl)phenylphosphine
Other names Triphos,
Identifiers
CAS number	23582-02-7 Y
Properties
Molecular formula	C34H29P3
Molar mass	534.55 g/mol
Appearance	white crystals
Melting point	129-130 °C
Solubility in water	Insoluble
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Triphos
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 references

Triphos is the name for two organophosphorus compounds. Both are air sensitive white solids that serve as tridentate ligands in coordination and organometallic chemistry. One is C₃-symmetric and the other has C_s symmetry.

Contents 1 Bis(diphenylphosphinoethyl)phenylphosphine 1.1 Synthesis 1.2 Coordination chemistry 2 1,1,1-Tris(diphenylphosphinomethyl)ethane 2.1 Synthesis 2.2 Coordination chemistry 3 References

Bis(diphenylphosphinoethyl)phenylphosphine

Bis(diphenylphosphinoethyl)phenylphosphine is called triphos, is a linear tridentate triphosphine.

Synthesis

Bis(diphenylphosphinoethyl)phenylphosphine is prepared by the free-radical-catalysed addition of phenylphosphine to vinyldiphenylphosphine:^[1]

2 Ph₂PCH=CH₂ + H₂PPh → [Ph₂PCH₂CH₂]₂PPh

Coordination chemistry

This isomer of triphos is more flexible and can bind to an octahedral metal center give either a facial or meridional isomers. Many of its derivatives are square planar complexes of the type [MX(triphos)]⁺ (M = Ni, Pd, Pt; X = halide).

1,1,1-Tris(diphenylphosphinomethyl)ethane

1,1,1-Tris(diphenylphosphinomethyl)ethane is called triphos.

Synthesis

Triphos is prepared by the reaction of sodium diphenylphosphide and CH₃C(CH₂Cl)₃:^[2]

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 adjacent coordination sites.^[3] Triphos complexes often exhibit high thermal stability. Such complexes are used to analyze mechanistic aspects of homogenous catalysts.^[4] 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.^[5]

Triphos sometimes behaves as a bidentate-chelating ligand. Illustrative cases include fac-[Mn(CO)₃Br(η²-triphos)] and [M(CO)₄(η²-triphos)],where M is Cr, Mo, or W. ^[3] 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. ^[6]

References

1. ^ "Synthesis of Polytertiary Phosphines and ‘Mixed’ Phosphorus–Sulphur and ‘Mixed’ Phosphorus–Nitrogen Polydentate Ligands via Free-Radical Catalysis" Daniel L. DuBois, William H. Myers and Devon W. Meek J. Chem. Soc., Dalton Trans., 1975, 1011-1015.doi:10.1039/DT9750001011
2. ^ 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. 
3. ^ ^{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:10.1016/0022-328X(95)06025-R. 
4. ^ 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. 
5. ^ 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". Organometallics 9: 226. doi:10.1021/om00115a035. 
6. ^ 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 (2): L185. doi:10.1016/S0020-1693(00)93540-0.