Abstract
The kinetics of 1,1-dimethylpropyl peroxy radicals recombination in polar solvents—water, methanol, and their mixtures—was studied by EPR spectroscopy in combination with the stopped-flow method, and the rate constants of this reaction were determined. Peroxyl radicals were generated by mixing solutions of Ce4+ sulfate and 1,1-dimethylpropyl hydroperoxide. The observed EPR signal of the peroxyl radical is a singlet with a g-factor of 2.015 ± 0.001, and a line width of ΔH = (1.36 ± 0.02) × 10−3 T for methanol and ΔH = (9.7 ± 0.2) × 10−4 T for water. The measured rate constants of (CH3)2C(O2 ·)CH2CH3 radical recombination at 298 K are 2k t = (3.9 ± 0.4) × 104 L mol−1 s−1 for water and 2k t = (5.2 ± 0.5) × 103 L mol−1 s−1 for methanol. A linear relationship between ln(2k t ) and the Kirkwood function (ε−1)/(2ε + 1), where e is the dielectric constant of the medium, has been established, indicating an important role of nonspecific solvation in the recombination of tertiary peroxyl radicals.
Similar content being viewed by others
References
Denisov, E.T. and Afanas’ev, I.B., Oxidation and Antioxidants in Organic Chemistry and Biology, Boca Raton, Fla.: CRC, Taylor and Francis Group, 2005.
Mill, T. and Hendry, D.G., in Comprehensive Chemical Kinetics, Bamford, C.H. and Tipper, C.F.., Eds., Amsterdam: Elsevier, 1980, vol. 16, p. 1.
Denisov, E.T., Denisova, T.G., Trepalin, S.V., and Drozdova, T.I., Data Base of Oxidation and Antioxidants in Organic Chemistry, Boca Raton, Fla.: CRC, Taylor and Francis Group, 2005.
Emanuel’, N.M., Zaikov, G.E., and Maizus, Z.K., Rol’ sredy v radikal’no-tsepnykh reaktsiyakh okisleniya organicheskikh soedinenii (Role of the Medium in FreeRadical Chain Oxidation of Organic Compounds), Moscow: Nauka, 1973.
Shuvalov, V.F., Cand. Sci. (Chem.) Dissertation, Chernogolovka, Moscow oblast: Inst. of Chemical Physics, 1977.
Caldin, E.F., Fast Reactions in Solution, Oxford: Blackwell, 1964.
Degtyareva, T.G., Solyanikov, V.M., and Denisov, E.T., Neftekhimiya, 1972, vol. 12, no. 6, p. 854.
Spravochnik khimika (Chemist’s Handbook), vol. 2: Osnovnye svoistva neorganicheskikh i organicheskikh soedinenii (Main Properties of Inorganic and Organic Compounds., Nikol’skii, B.P., Ed., Leningrad: Goskhimizdat, 1963, 2nd ed.
Handbook of Chemistry and Physics, Lide, D.R., Ed., Boca Raton, Fla.: CRC, Taylor and Francis Group, 2004–2005, 85th ed.
Howard, J.A., in Advances in Free Radical Chemistry, Williams, G.H., Ed., London: Logos, 1972, vol. 4, p. 49.
Denisov, E.T., Sarkisov, O.M., and Likhtenshtein, G.I., Khimicheskaya kinetika (Chemical Kinetics), Moscow: Khimiya, 2000.
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © T.G. Denisova, V.F. Shuvalov, 2016, published in Kinetika i Kataliz, 2016, Vol. 57, No. 1, pp. 25–28.
Rights and permissions
About this article
Cite this article
Denisova, T.G., Shuvalov, V.F. Recombination of 1,1-dimethylpropyl peroxy radicals in polar solvents. Kinet Catal 57, 22–25 (2016). https://doi.org/10.1134/S0023158416010031
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S0023158416010031