Kinetics and mechanism of ozone addition to tetrafluoroethylene and hexafluoropropylene

• Published in: Russian chemical bulletin Vol. 70; no. 1; pp. 132 - 139
• Main Authors: Kiryukhin, D. P., Krisyuk, B. E., Maiorov, A. V.
• Format: Journal Article
• Language: English
• Published: New York Springer US 2021; Springer Nature B.V
• Subjects: Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Full Articles; Inorganic Chemistry; Low temperature; Organic Chemistry; Ozone; Quantum chemistry; Rate constants; cryoscopic calorimetry; quantum chemical calculation; hexafluoropropylene; activation energy; rate constant; ozone; tetrafluoroethylene
• ISSN: 1066-5285; 1573-9171
• DOI: 10.1007/s11172-021-3067-9

The DSC method was used to study the low-temperature (77–280 K) ozonolysis of perfluoroleflns, tetrafluoroethylene (TFE) and hexafluoropropylene (HFP), in the direct interaction with ozone in the absence of solvents and oxygen. The values of activation energy ( E a /kJ mol −1 ), rate constants ( k /L (mol s) −1 ), and the Arrhenius equation were obtained: for TFE k = 1.2 · 10 6 exp[(−42.0±2)/( RT )] at T = 150–165 K and for HFP k = 1.2 · 10 3 exp[(−39.9±2)/( RT )] at T = 170–190 K. The quantum chemical calculation for the addition of ozone to TFE and HFP via the mechanisms of concerted (Criegee mechanism) and nonconcerted (DeMore mechanism) addition was performed at the UB2PLYP/aug-cc-pVDZ level. The ozonolysis of TFE proceeds via the DeMore mechanism, whereas both mechanisms contribute certainly to the reaction of HFP ozonolysis.