Abstract:The stoichiometry and rate constants for the reaction of triphenylphosphite and triphenylphosphine with ozone were measured at several temperatures. The rate was first order in each reactant, with k = (3f 1) x lo4 and ( 5 f 2 ) x lo3 M -' s-' , respectively, for the reaction of ozone with triphenylphosphine and triphenylphosphite (2,4-dimethylhexane, -9 0 ) . The reaction of ozone with triphenylphosphite has a low activation energy in carbon tetrachloride. The stoichiometry was 1:l for both compounds under the… Show more
“…After warming the solution to +20 °C (Figure b), signal a1 at δ 31P −62.8 ppm disappeared to give cleanly the signal of triphenyl phosphate 8 (δ P = −17.3 ppm) with exhaustion of molecular oxygen. Thus, our experiments well reproduced the reported results …”
Section: Resultssupporting
confidence: 93%
“…The formation of TPPO (δ 31P −62.8 ppm, relative to 85% H 3 PO 4 ; lit. −63 ppm (ref a)), signal a1, and small amount of triphenyl phosphate 8 (δ 31P −17.3 ppm), signal a2, were clearly observed (Figure a). 1 …”
Section: Resultsmentioning
confidence: 96%
“…Triphenyl phosphite ozonide (TPPO), formed by the addition of ozone to triphenyl phosphite below −70 °C, has attracted considerable attention from its unique structure and reactivity (Scheme ). − The decomposition spontaneously occurs at ca. −30 °C to give triphenyl phosphate and singlet oxygen. 3b,d, Thus, the ozonide (TPPO) has been well recognized as a chemical source of singlet oxygen ( 1 O 2 ).…”
The direct oxygenation of s-trans dienes, silyl dienol ethers (SDEs) 2, by triphenyl phosphite ozonide (TPPO) has been examined in detail. The regioselective oxygenation was found to give hydroperoxide 3, alcohol 4, ketone 5, dimer 6, and peroxy phosphate 7 with concomitant formation of triphenyl phosphate 8 and diphenyl trimethylsilyl phosphate 10. The formation of peroxy phosphate 7 was found for the first time in TPPO oxygenation reactions. The low temperature (31)P and (1)H NMR spectroscopic analyses proved the direct reaction of SDEs with TPPO without generation of singlet oxygen. The formation of the oxygenated products 3-7 is reasonably explained by the intervention of the zwitterion ZI, which can be formed by the nucleophilic attack of SDE to the central oxygen of the ozonide. The regioselective attack of SDE to the central oxygen of the ozonide was supported by the quantum chemical calculation (B3LYP/6-31G).
“…After warming the solution to +20 °C (Figure b), signal a1 at δ 31P −62.8 ppm disappeared to give cleanly the signal of triphenyl phosphate 8 (δ P = −17.3 ppm) with exhaustion of molecular oxygen. Thus, our experiments well reproduced the reported results …”
Section: Resultssupporting
confidence: 93%
“…The formation of TPPO (δ 31P −62.8 ppm, relative to 85% H 3 PO 4 ; lit. −63 ppm (ref a)), signal a1, and small amount of triphenyl phosphate 8 (δ 31P −17.3 ppm), signal a2, were clearly observed (Figure a). 1 …”
Section: Resultsmentioning
confidence: 96%
“…Triphenyl phosphite ozonide (TPPO), formed by the addition of ozone to triphenyl phosphite below −70 °C, has attracted considerable attention from its unique structure and reactivity (Scheme ). − The decomposition spontaneously occurs at ca. −30 °C to give triphenyl phosphate and singlet oxygen. 3b,d, Thus, the ozonide (TPPO) has been well recognized as a chemical source of singlet oxygen ( 1 O 2 ).…”
The direct oxygenation of s-trans dienes, silyl dienol ethers (SDEs) 2, by triphenyl phosphite ozonide (TPPO) has been examined in detail. The regioselective oxygenation was found to give hydroperoxide 3, alcohol 4, ketone 5, dimer 6, and peroxy phosphate 7 with concomitant formation of triphenyl phosphate 8 and diphenyl trimethylsilyl phosphate 10. The formation of peroxy phosphate 7 was found for the first time in TPPO oxygenation reactions. The low temperature (31)P and (1)H NMR spectroscopic analyses proved the direct reaction of SDEs with TPPO without generation of singlet oxygen. The formation of the oxygenated products 3-7 is reasonably explained by the intervention of the zwitterion ZI, which can be formed by the nucleophilic attack of SDE to the central oxygen of the ozonide. The regioselective attack of SDE to the central oxygen of the ozonide was supported by the quantum chemical calculation (B3LYP/6-31G).
“…Razumovskii et al (67) determined the rate constants for reaction of ozone with polymer solutions in CCl 4 at 20°C and it was 7.5 x 10 5 for natural rubber. He studied the rate constants for the reactions of ozone with triphenyl phosphite and triphenylphosphine at several temperatures (68) . The rate in dimethyl hexane was of first order in each reactant, with K = (3 ± 1) x 10 4 and (5 ± 2) x 10 3 M -1 sec -1 , respectively the reaction of ozone with triphenylphosphine had a lower activation energy in CCl 4 .…”
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
