ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Potassium persulfate oxidizes triphenylphosphine to triphenylphosphine oxide in 60% aqueous acetonitrile. It has been suggested that the oxygen of the product, triphenylphosphine oxide, might originate from solvent water, following nucleophilic attack on an intermediate phosphonium ion. We have investigated the origin of the oxygen in the oxidation of triphenylphosphine by potassium persulfate in 60% aqueous acetonitrile containing 20% [18O]water. The product was analyzed by using the 18O isotope effect in 31P NMR spectroscopy. The magnitude of the 18O isotope-induced shift was determined by synthesizing triphenylphosphine [18O]oxide and was found to be 0.038 ppm upfield. The product of the oxidation reaction in 20% [18O]water displayed no 18O isotope effect. The origin of the oxygen in the oxidation reaction is the persulfate ion, consistent with an alternative mechanism involving nucleophilic attack by water at the sulfur atom of a phosphonium peroxysulfate intermediate.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/kin.550160912
