Triphenyl Phosphite Ozonide

[29833-83-8] C18H15O6P (MW 358.30) InChI = 1S/C18H15O6P/c1-4-10-16(11-5-1)19-25(23-22-24-25,20-17-12-6-2-7-13-17)21-18-14-8-3-9-15-18/h1-15H InChIKey = BVCCTQHXJQXLKM-UHFFFAOYSA-N (source of singlet oxygen;2 avoids complicating effects of radiation on reactants and products sometimes associated with photochemical generation of singlet oxygen; can also transfer dioxygen in a bimolecular process3 not involving singlet oxygen) Physical Data: reagent is labile and is prepared and used in situ. Solubility: sol dichloromethane, carbon tetrachloride, benzene, acetonitrile, trichlorofluoromethane, toluene, chlorobenzene, methanol, isopropyl alcohol, acetone, diethyl ether, and pyridine. Form Supplied in: reagent is prepared as needed. Analysis of Reagent Purity: 31P NMR. Preparative Methods: a solution of triphenyl phosphite in CH2Cl2 is added to O3-saturated (blue color) CH2Cl2 at −78 °C. Ozone is added periodically in order to maintain the blue color. The alternative procedure of adding ozone to a solution of the triphenyl phosphite in CH2Cl2 leads to lower yields of the ozonide since the phosphite reacts with the ozonide. When the ozonide is to be used as a source of singlet oxygen the solution is allowed to warm to about −25 °C in the presence of the substrate. Direct transfer of dioxygen in a bimolecular process occurs at −70 °C.2, 4, 5 Handling, Storage, and Precautions: decomposes with O2 evolution at temperatures above about −25 °C. While solid triphenyl phosphite ozonide has occasionally been isolated1b,6-8 this procedure is not recommended since the solid has been observed1b,7, 8 to detonate, with flashes of red light, upon warming.