Thermal Stability of Cyclododecylidene-1,1-bishydroperoxide in the Presence of Ferrocene
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mal Stability of Cyclododecylidene-1,1-bishydroperoxide in the Presence of Ferrocene N. M. Andriyashinaa, S. A. Grabovskya,*, and N. N. Kabalnovaa a Ufa
Institute of Chemistry, Russian Academy of Sciences, Ufa, 450054 Russia *e-mail: [email protected] Received June 26, 2020; revised June 26, 2020; accepted July 9, 2020
Abstract—Thermal stability of cyclododecylidene-1,1-bishydroperoxide in xylene has been studied and activation parameters of the reaction have been determined. The thermolysis has been accompanied by the reaction with ferrocene and the induced radical chain decomposition of cyclododecylidene-1,1-bishydroperoxide. Keywords: cyclododecylidene-1,1-bishydroperoxide, ferrocene, thermal stability
DOI: 10.1134/S1070363220110018
The ferrocene–peroxide system is known to initiate the processes of olefins polymerization [1–6]. Benzoyl peroxide interaction with ferrocene has been the best studied [7–10]. It has been recently shown that benzoyl peroxide in the presence of ferrocene is consumed simultaneously in several reactions including heatinduced decomposition, decomposition induced by iron(III) ions, and the reaction with ferrocene yielding ferrocenium cation-radical [11]. The data on the interaction of hydroperoxides with ferrocene have been scarce and controversial. For example, hydroperoxides of butyl, tert-butyl, and cumyl are inactive in the reaction with ferrocene [8]. The ESR study has shown that ferrocene derivatives slowly decompose t-BuOOH with the formation of alkoxy radicals, the interaction revealing the induction period [12]. The reactions between FcBF4 and t-BuOOH are fast [Eqs. (1), (2)]. Characteristic blue-green color of the ferrocenium salt solution has instantly turned yellow (typical of reduced ferrocene) upon addition of t-BuOOH. Fc + t-BuOOH → Fc+• + OH− + t-BuO• (slow),
(1)
FcBF4 + t-BuOOH → Fc + HBF4 + t-BuOO• (very fast).
(2)
A series of studies have reported the investigation of ferrocene derivatives with hydrogen peroxide, organic peroxides, and certain hydroperoxides in the presence of acids [13–15]. It has been shown that alkanes are readily oxidized by H2O2 or t-BuOOH into the corresponding
alkyl hydroperoxides under mild homogeneous conditions in the presence of catalytic amounts of ferrocene and pyrazine-2-carboxylic acid [16]. The data on thermal stability of 1,1-bishydroperoxides (efficient catalysts of olefins polymerization) have been scarce as well [17–19]. It has been reported that cyclic 1,1-bishydroperoxides are relatively stable at room temperature, and their stability is increased with the increase in molecular mass. For example, cyclododecylidene-1,1-bishydroperoxide and 2-n-nonylcyclododecylidene-1,1-bishydroperoxide can be stored at room temperature during up to 6 months without any sign of decomposition [20, 21]. Herein we investigated thermal stability of cyclododecylidene-1,1-bishydroperoxide 1 in xylene in the presence as well as in the absence of ferrocene. Kinetic curves of compound 1 consumption followed the firstorder equation with high correlation c
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