Phosphinous acid

Phosphinous acid
Names
	Other names hydroxyphosphine
Identifiers
CAS Number	13840-40-9;
3D model (JSmol)	Interactive image;
ChemSpider	126521;
PubChem CID	143409;
CompTox Dashboard (EPA)	DTXSID80276387 ;
	InChI InChI=1S/H3OP/c1-2/h1H,2H2 Key: RYIOLWQRQXDECZ-UHFFFAOYSA-N;
	SMILES OP;
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

Phosphinous acid is the inorganic compound with the formula H₂POH. It exists, fleetingly, as a mixture with its less stable tautomer H₃PO (phosphine oxide). This mixture has been generated by low temperature oxidation of phosphine with ozone.^[1] H₂POH is mainly of pedagogical interest. Organophosphinous acids are more prevalent than the parent H₂POH.

Organophosphinous acids

Phosphinous acids exist mainly as minor tautomers of secondary phosphine oxides. For example diphenylphosphinous acid, which is not detectable directly, is invoked as the tautomer of diphenylphosphine oxide.

Highly electron-withdrawing substituents stabilize the phosphinous acid tautomer as illustrated by (CF₃)₂POH.^[2]

References

^ Withnall, Robert; Andrews, Lester (1987). "FTIR spectra of the photolysis products of the phosphine-ozone complex in solid argon". Journal of Physical Chemistry. 91 (4): 784–97. doi:10.1021/j100288a008.
^ Bader, Julia; Berger, Raphael J. F.; Stammler, Hans-Georg; Mitzel, Norbert W.; Hoge, Berthold (2011). "First Solid-State Structures of Real Diorganyl Phosphinous Acids R₂POH (R=CF₃, C₂F₅)". Chemistry - A European Journal. 17 (48): 13420–13423. doi:10.1002/chem.201102370. PMID 22052837.

[1] Withnall, Robert; Andrews, Lester (1987). "FTIR spectra of the photolysis products of the phosphine-ozone complex in solid argon". Journal of Physical Chemistry. 91 (4): 784–97. doi:10.1021/j100288a008.

[2] Bader, Julia; Berger, Raphael J. F.; Stammler, Hans-Georg; Mitzel, Norbert W.; Hoge, Berthold (2011). "First Solid-State Structures of Real Diorganyl Phosphinous Acids R₂POH (R=CF₃, C₂F₅)". Chemistry - A European Journal. 17 (48): 13420–13423. doi:10.1002/chem.201102370. PMID 22052837.

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