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Tris(trimethylsilyl)phosphine

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Tris(trimethylsilyl)phosphine
Names
Other names
tris(trimethylsilyl)phosphane
Identifiers
ECHA InfoCard 100.154.516 Edit this at Wikidata
Properties
C9H27PSi3
Molar mass 250.544 g·mol−1
Appearance colorless liquid
Density 0.863 g/cm3
Melting point 24 °C (75 °F; 297 K)
Boiling point 243–244 °C (469–471 °F; 516–517 K)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
poison, inflammable
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Tris(trimethylsilyl)phosphine is the organophosphorus compound with the formula P(SiMe3)3 (Me = methyl). It is a colorless liquid that ignites in air and hydrolyses readily.[1]

Synthesis

Tris(trimethylsilyl)phosphine is prepared by treating trimethylsilyl chloride, white phosphorus, and sodium-potassium alloy:[2]

1/4 P4 + 3 Me3SiCl + 3 K → P(SiMe3)3 + 3 KCl

Several other methods exist.[1]

Copper phosphide cluster Cu96P30{P(SiMe3)2}6(PEt3)18 with C and H atoms omitted for clarity (red=Cu, purple=P, gray=Si). Tris(trimethylsilyl)phosphine the reagent used to install the phosphide ligands.[3]

Reactions

The compound hydrolyzes to give phosphine:

P(SiMe3)3 + 3 H2O → PH3 + 3 HOSiMe3

Treatment of certain acyl chlorides with tris(trimethylsilyl)phosphine gives phosphaalkynes, one example being tert-butylphosphaacetylene.[4]

Synthesis of a phosphaalkyne using tris(trimethylsilyl)phosphine.

Reaction with potassium tert-butoxide cleaves one P-Si bond, giving the phosphide salt:[5]

P(SiMe3)3 + KO-t-Bu → KP(SiMe3)2 + Me3SiO-t-Bu

It is a reagent in the preparation of metal phosphido clusters by reaction with metal halides or carboxylates. In such reactions the silyl halide or silyl carboxylate is liberated as illustrated in this idealized reaction:

P(SiMe3)3 + 3 CuCl → Cu3P + 3 ClSiMe3

Safety

Tris(trimethylsilyl)phosphine spontaneously ignites in air, thus it is handled using air-free techniques.

References

  1. ^ a b Kosarev, Sergey A.; Collier, Steven J. (2011). "tris(trimethylsilyl)phosphin". Handbook of Reagents for Organic Synthesis: Reagents for Silicon-Mediated Organic Synthesis: 422–427. doi:10.1002/047084289X.rn01332. {{cite journal}}: Cite has empty unknown parameter: |1= (help)
  2. ^ Becker, Gerd; Schmidt, Helmut; Uhl, Gudrun; Uhl, Werner (1990). "Tris(trimethylsilyl)phosphine and lithium bis(trimethylsilyl)phosphide·bis(tetrahydrofuran)". Inorganic Syntheses. 27: 243–9. doi:10.1002/9780470132586.ch48.
  3. ^ Fenske, D.; Holstein, W. (1994). "[Cu96P30{P(SiMe3)2}6(PEt3)18], a New Phosphorus-Bridged Copper Cluster". Angew. Chem. Int Ed. Engl. 33: 1290–1292. doi:10.1002/anie.199412901.
  4. ^ M. Regitz (1990). "Phosphaalkynes: new building blocks in synthetic chemistry". Chem. Rev. 90: 191–213. doi:10.1021/cr00099a007..
  5. ^ "Phosphaalkynes". Phosphorus(III) Ligands in Homogeneous Catalysis. Wiley-VCH. 2012. pp. 343–354. doi:10.1002/9781118299715.ch11. {{cite book}}: Unknown parameter |authors= ignored (help); Unknown parameter |editors= ignored (|editor= suggested) (help)