Phosphine oxide

See also: Phosphine oxides

Phosphine oxide is the inorganic compound with the formula H₃PO. Although stable as a dilute gas, liquid or solid samples are unstable. Unlike many other compounds of the type PO_xH_y, H₃PO is rarely discussed and is not even mentioned in major sources on main group chemistry.^[1]

Phosphine oxide

Identifiers
CAS Number	13840-40-9
3D model (JSmol)	Interactive image
PubChem CID	57448882
InChI InChI=1S/H3OP/c1-2/h2H3 Key: MPQXHAGKBWFSNV-UHFFFAOYSA-N
SMILES [O-][PH3+]
Properties
Chemical formula	H3OP
Molar mass	49.997 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

H₃PO has been detected by mass spectrometry as a reaction product of oxygen and phosphine,^[2] by means of FT-IR in a phosphine-ozone reaction^[3]

Generation

Phosphine oxide has been claimed as the product of a reaction of phosphine with vanadium oxytrichloride as well as with chromyl chloride. The product was obtained by matrix isolation.^[4] It has also been reported relatively stable in a water-ethanol solution by electrochemical oxidation of white phosphorus, where it slowly disproportionates into phosphine and hypophosphorous acid.^[5]

Phosphine oxide is reported as an intermediate in the room-temperature polymerization of phosphine and nitric oxide to solid P_xH_y.^[6]

Further reading

• Chesnut, D. B.; Savin, A. (1999). "The Electron Localization Function (ELF) Description of the PO Bond in Phosphine Oxide". Journal of the American Chemical Society. 121 (10): 2335–2336. doi:10.1021/ja984314m.
• Alkorta, Ibon; Sánchez-Sanz, Goar; Elguero, José; Del Bene, Janet E. (2014). "Pnicogen Bonds between X═PH₃ (X = O, S, NH, CH₂) and Phosphorus and Nitrogen Bases". The Journal of Physical Chemistry A. 118 (8): 1527–1537. Bibcode:2014JPCA..118.1527A. doi:10.1021/jp411623h. PMID 24547683.