Kinetics and mechanism of the reaction of ozone with 3,6-di-tert-butylpyrocatechol

The reaction of ozone with 3,6-di-tert-butylpyrocatechol at 20°C was investigated, and it was found that the main reaction product was 3,6-di-tert-butylquinone, while the reaction rate was proportional to the concentrations of the reagents. A reaction scheme explaining the mechanism of formation of the main and side products is proposed.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1443–1447, June, 1992.     

Rules for antioxidant action of 3,6-di-tert-butylpyrocatechol

Russian Chemical Bulletin -     

Reaction of 3,6-di-tert-butylpyrocatechol with thionyl chloride in the presence of dimethylformamide

Conclusions An unusual type of reaction of 3,6-di-tert-butylpyrocatechol with thionyl chloride was discovered, which leads to the formation of elementary sulfur. A mechanism, including the formation of sulfuran, was proposed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1635–1637, July, 1984.     

Interaction of bromine with 3,6-di-tert-butylpyrocatechol and its ethers and esters

Conclusions 3, 6-Di-tert-butylpyrocatechol forms 3,4-dibromo-6-tert-butylpyrocatechol on bromination. Protection of one or both hydroxyl groups allows a classical electrophilic substitution to be carried out.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1100–1103, May, 1977.     

Low-temperature oxidation of 3,6-di-tert-butyl-o-benzoquinone and 3,6-di-tert-butylpyrocatechol with tert-butyl hydroperoxide in the presence of aluminum, titanium, and zirconium tert-butylates

Systems consisting of metal (Al, Ti, Zr) tert-butylate and tert-butyl hydroperoxide oxidize 3,6-di-tert-butyl-o-benzoquinone under mild conditions (room temperature, benzene). With (t-BuO)₃Al and (t-BuO)₄Zr, the major reaction products are 5-hydroxy-3,6-di-tert-butyl-2,3-epoxy-p-benzoquinone, and with (t-BuO)₄Ti, 2-hydroxy-3,6-di-tert-butyl-p-benzoquinone. Under the conditions of this reaction, 3,6-di-tert-butylpyrocatechol initially transforms into 3,6-di-tert-butyl-o-benzoquinone. The reactions involve metalcontaining peroxides.     

Delocalization of unpaired electron in anion-radicals of diethyldiphenyl- and tetraphenylsilanes

Conclusions In the anion-radicals of diethyldiphenylsilane and tetraphenylsilane the delocalization of the unpaired electron bears a dynamic character, which is manifested in a strong alternation of the width of the line with change in the temperature.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2114–2116, September, 1972.     

An intramolecular charge/electron transfer chemiluminescence mechanism of oxidophenyl-substituted 1,2-dioxetane

The chemiluminescence (CL) mechanism of oxidophenyl-substituted 1,2-dioxetane was investigated by performing TD-DFT calculations on biradicals of three model compounds. We propose a novel mechanism of CL in which excitation of a dissociative intermediate by infrared radiation (IRE) of the surrounding solvent is considered. The excitation energies and oscillator strengths (f-values) were estimated for intermediates along the reaction coordinate (Rx). The difference in efficiencies of CL between syn- and anti-isomers of m-oxidophenyl-dioxetane is explained using the difference in potential curves of the singlet excited states (S) and the IRE mechanism. At the point where the biradical of the anti-isomer decomposes into two fragments, the interaction between the S and triplet (T) states is induced by a significant back electron transfer (BET) from the dioxetane group to the oxido-phenyl group and the S(1) excited state is stabilized and CL efficiency is enhanced. In the syn-isomer, the barrier in the S(1) potential curve to reach the final CL state is higher than for the anti-isomer, which reduces the efficiency. The poor CL yield for the p-isomer is ascribed to a much higher barrier in the potential curve of the S(1) state.