- Solvent effect on the rate of β-scission of the tert-butoxyl radical
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The transient absorption spectrum of the tert-butoxyl radical in the UV region was obtained by the laser flash photolysis technique. The rate constants for β-scission and self-termination reactions of tert-butoxyl radicals were measured in five solvents; the Arrhenius parameters of the rate constant for β-scission kβ were determined. It was shown that both the solvent polarity and ability for hydrogen bonding accelerate the reaction of β-scission. The solvent effect on the rate constant of the β-scission reaction is discussed in terms of a simple Onzager-Betcher model, a point dipole model, and a model of the H-bonded complex of the radical with the solvent molecule.
- Tsentalovich, Yuri P.,Kulik, Leonid V.,Gritsan, Nina P.,Yurkovskaya, Alexandra V.
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- Autoxidation of Biological Molecules. 2. The Autoxidation of a Model Membrane. A Comparison of the Autoxidation of Egg Lecithin Phosphatidylcholine in Water and in Chlorobenzene
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The kinetics of autoxidation of egg lecithin phosphatidylcholine in homogeneous solution in chlorobenzene and as a bilayer dispersion in 0.1 M aqueous NaCl has been studied at 30 deg C under 760 torr of O2.The autoxidations were initiated by the thermal decomposition of di-tert-butyl hyponitrile.The efficiency of chain initiation, e, was determined by the induction period method using α-tocopherol as the chain-breaking antioxidant.In chlorobenzene e was ca. 0.66 but in the aqueous dispersion e was only ca. 0.091.The reduced efficiency of initiation in the bilayeris attributed to a reduction in the fraction of tert-butoxyls which escape from the solvent cage, and this in turn is due to the fact that the bilayer has a high microviscosity.The rate of autoxidation of the egg lecithin in chlorobenzene is proportional to the lecithin concentration and to the square root of the rate of chain initiation, and is virtually independent of the oxygen pressure, which means that this autoxidation follows the usual kinetic rate law.In the aqueous dispersion the concentration of egg lecithin in the bilayer cannot be altered, but since the rate of autoxidation is proportional to the square root of the rate of chain initiation and is virtually independent of the oxygen pressure, the usual kinetic rate law would also appear to be followed.The oxidizability of egg lecithin in chlorobenzene is 0.61 M-1/2 s-1/2, and in the aqueous dispension it is 0.0165 M-1/2 s-1/2.The reduction in oxidizability in the bilayer is attributed to the diffusion of the peroxyl radical center, which is a polar moiety, out of the autoxidizable, nonpolar, interior region of the bilayer and into the nonautoxidizable, polar surface region.As a consequence, chain progogation will be retarded and chain termination will be accelerated.
- Barclay, L.R.C.,Ingold, K.U.
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- Interaction of 9-substituted anthracenes with oxidation systems tert-butylhydroperoxide-metal tert-butoxide
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9-R-Anthracenes (R = Me, Ph) are effective acceptors of peroxyl and metalalkoxyl radicals in the systems tert-butylhydroperoxide-metal tert-butoxide (M = Al, V, Cr; C6H6, 20°C). Isolation of 9-R-9,10-dihydro-9,10-di-tert-butylperoxyanthracenes, 10-R-10-tert-butylperoxy-9-anthrones as major products reliably confirms the formation of tert-butylperoxy radicals and can be used for quantitative assessment of their content.
- Stepovik,Malysheva,Fukin
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- Titanium tetra-tert-butoxide-tert-butyl hydroperoxide oxidizing system: Physicochemical and chemical aspects
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The reaction of titanium tetra-tert-butoxide with tert-butyl hydroperoxide (1: 2) (C6H6, 20 C) involves the steps of formation of the titanium-containing peroxide (t-BuO)3TiOOBu-t and peroxytrioxide (t-BuO)3TiOOOBu-t. The latter decomposes with the release of oxygen, often in the singlet form, and also homolytically with cleavage of both peroxy bonds. The corresponding alkoxy and peroxy radicals were identified by ESR using spin traps. The title system oxidizes organic substrates under mild conditions. Depending on the substrate structure, the active oxidant species can be titanium-containing peroxide, peroxytrioxide, and oxygen generated by the system.
- Stepovik,Gulenova,Martynova,Mar'Yasin,Cherkasov
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- Kinetic study of the reactions of tert-butyl radicals in the liquid phase in the presence and absence of oxygen
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The photolyses of solutions of 2,2′-azoisobutane and 2,2,4,4-tetramethylpentan-3-one in decane in glass and metal cells, have been used to generate tert-butyl and, by reaction with oxygen, tert-butylperoxyl radicals. Time-dependent product yields from reactions in oxygenated and oxygen-free solutions have been measured over a range of temperatures (298-398 K). For each precursor, for a given set of conditions, the general features of the reactions are independent of the cell used, although the absolute rates of product formation are different. The major difference between the reactions of the two precursors lies in the initial photochemical step. For 2,2′-azoisobutane this leads directly to two tert-butyl radicals whereas the ketone gives a tert-butyl and a 2,2-dimethylpropanoyl radical. The product distributions can be accounted for in terms of the reactions of these radicals within a solvent cage in competition with cage escape and subsequent reaction. A single kinetic model that accounts for the reactions of both precursors, in the presence or absence of oxygen, at the temperatures studied, is described.
- Costello, Andrew R.,Lindsay Smith, John R.,Stark, Moray S.,Waddington, David J.
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- Induced decomposition of di(tert-butyl)trioxide
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Thermal decomposition of di(tert-butyl)trioxide (ButOOOBut) in a wide range of concentrations was studied by visible and IR chemiluminescence. Induced decomposition of ButOOOBut caused by its reaction with the peroxy radicals formed in the solvent (CH2Cl2) was found and investigated.
- Khursan,Khalizov,Shereshovets
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- The role of onium salts in the oxidation of hydrocarbons by O2 catalysed by cationic phase-transfer reagents
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Systematic investigations by Fukui et al. concluded that the oxidation of hydrocarbons (p-xylene, cumene, etc) can be accelerated not only by ammonium salts, but also by other onium salts, such as sulfonium, phosphonium, selenonium, arsonium, and the telluronium salts. An explanation for the long-observed fact that the catalytic activities of cationic phase transfer catalysts depend on the nature of the counteranions in the onium salts was presented. Such decomposition of the model substance tert-butyl hydroperoxide (t-BHP) results in O2, tert-butanol (90-95%), di-tert-butyl peroxide (5-10%), and traces of CO2. It was assumed that the interaction between hydroperoxide and onium cation was mainly electrostatic in nature and that its effectivity depended on the positive charge density on the onium cation, which was controlled by the nature and dimensions of the counteranion. The role of water in the decomposition of t-BHP was also revealed.
- Csanyi,Palinko,Rockenbauer,Jaky,Korecz
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- Recombination of Tertiary Butyl Peroxy Radicals. Part 1.-Products Yields between 298 and 373 K
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Overall product distributions resulting from the recombination of t-butyl peroxy radicals have been studied over the temperature range 298-373 K.The results indicate that over this range there is a switch from the terminating channels (forming alcohol and aldehyde/ketone) towards non-terminating channels (forming two alkoxy radicals) for the two further recombination processes that follow the initial combination of t-butyl peroxy radicals:.There is also direct evidence for the presence of a terminating channel to form di-t-butyl peroxide.This reaction proceeds at a rate of ca. 0.14 of the non-terminating recombination rate at 298 K, but this fraction falls to 0.025 at 333 K and the reaction is not evident at 373 K.Our results demonstrate the importance of abstraction reactions involving alkoxy radicals (t-butoxy and methoxy) and one of the principal recombination products, t-butyl hydroperoxide.Rate constant ratios involving these processes have been derived from the product distributions and from additional studies in which t-butyl hydroperoxide was added.Rate constants of ca. 10-13 cm3 molecule-1 s-1 for these abstraction processes are consistent with our results.
- Kirsch, Leslie J.,Parkes, David A.
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- HETEROGENEOUS CATALYSIS IN THE LIQUID-PHASE OXIDATION OF OLEFINS. - 4. THE ACTIVITY OF A SUPPORTED VANADIUM OR CHROMIUM OXIDE CATALYST IN THE DECOMPOSITION OF t-BUTYL HYDROPEROXIDE.
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The liquid-phase decomposition of t-butyl hydroperoxide (t-BuOOH) has been carried out in benzene under an N//2 atmosphere using a vanadium or chromium oxide, supported on gamma -Al//2O//3 or SiO//2 as the catalyst, for the purpose of clarifying the reaction mechanism of the cyclohexane oxidation. The decomposition of t-BuOOH on the supported oxide catalyst was a first-order reaction; the main products were t-butyl alcohol, di-ti-butyl peroxide, and acetone, suggesting that t-BuOOH is decomposed homolytically on the catalyst by the Haber-Weiss mechanism. The effect of the vanadium-chromium binary system formation was small, but the interaction between metal oxides and the supports appeared to be important in the t-BuOOH decomposition.
- Takehira,Hayakawa,Ishikawa
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- Kinetic Electron Paramagnetic Resonance Study of the Reactions of t-Butylperoxyl Radicals in Aqueous Solution
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The kinetics of reactions of t-butylperoxyl radicals in aqueous solution have been measured using electron paramagnetic resonance, ultraviolet absorption spectroscopy and gas chromatography.The rate constants for the overall self-reaction, the separate terminating and non-terminating reactions are very similar to those observed in non-polar solvents and the gas phase.The t-butoxy radicals, formed by the non-terminating reaction, can either undergo scission, which leads to methylperoxyl radicals, or react with further t-butyl hydroperoxide to regenerate t-butylperoxy radicals.The cross-termination reaction between methylperoxyl and t-butylperoxyl radicals is an important route in the overall termination sequence.The propagation reaction occurs significantly only at high concentrations of t-butyl hydroperoxide, ( > 0.3 mol dm-3) and its rate constant is much lower than that in non-polar solutions.
- Bennett, John E.
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- Process for producing organic peroxides
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The present invention relates to a method for producing organic peroxides and separating, purifying and concentrating sulfuric acid from aqueous effluents of said organic peroxide production process.
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Paragraph 0097-0099
(2021/09/29)
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- PROCESS FOR PRODUCING AN ORGANIC PEROXIDE
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This invention relates to a process for producing an organic peroxide and isolating, purifying, and concentrating the sulfuric acid from the aqueous effluents of said organic peroxide production process.
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Page/Page column 15
(2020/09/08)
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- Method for continuously producing tert-butyl hydroperoxide
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The invention relates to a method for continuously producing tert-butyl hydroperoxide, wherein the method comprises the following steps: adding tert-butyl alcohol and hydrogen peroxide into a reactiondevice, and carrying out catalytic heating to obtain a mixture of tert-butyl alcohol, water, tert-butyl hydroperoxide and di-tert-butyl peroxide; a water phase and an oil phase are separated, the oilphase is rectified, a tert-butyl hydroperoxide product is produced at a tower kettle of a rectifying tower, a mixture of water, tert-butyl alcohol and di-tert-butyl peroxide is produced at the towertop of the rectifying tower, part of a water layer flows back after the mixture is layered through a reflux tank, a mixture of tert-butyl alcohol and di-tert-butyl peroxide is produced at an oil layer, and the oil layer is washed with water and then layered; the separated oil layer is di-tert-butyl peroxide, the water layer is stripped by a stripping tower, the tower top of the stripping tower isa tert-butyl alcohol aqueous solution, the tert-butyl alcohol aqueous solution returns to the reaction device for reaction, and water at the tower kettle of the stripping tower is recycled. The process is continuous in production, convenient for automatic control, high in recovery rate and high in separation rate. The reaction, separation and purification processes are optimized, the wastewater amount is reduced, the product purity is high, and the quality is stable.
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Paragraph 0024-0028
(2020/12/15)
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- Synthetic method for dialkyl peroxide
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The invention belongs to the technical field of chemical synthesis, and in particular relates to a synthetic method for dialkyl peroxide. The method comprises the following step: adding an alkyl alcohol compound, a compound containing a peroxide bond and a polyvinyl alcohol compound amino acid catalyst into an organic solvent to be stirred and dehydrated to react to synthesize the dialkyl peroxide, wherein the polyvinyl alcohol compound amino acid catalyst is prepared by polymerizing a spherical polyvinyl alcohol matrix and compound amino acids. In a production process of the peroxide, a chemical raw material sulfuric acid or sodium hydroxide with certain corrosion is avoided, the synthetic process of the peroxide is optimized, and the waste water discharge containing sulfuric acid or sodium hydroxide in the industrial production process is reduced.
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Paragraph 0057-0062; 0075-0076
(2019/04/13)
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- Di-tert-butyl peroxide production process
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The invention relates to the field of processing and production of oxides, particularly to a di-tert-butyl peroxide production process, which comprises: (1) selecting raw materials; and (2) adding hydrogen peroxide into a reaction kettle, starting stirring, opening a coolant valve, slowly adding sulfuric acid to the reaction kettle, slowly adding t-butanol into the reaction kettle, closing the coolant valve after completing the adding, heating with hot water, carrying out a reaction for 1-3 h, closing the stirring, standing, separating the waste acid to enter a waste acid storage tank, placingthe upper layer organic phase (crude product) in a washing kettle, washing for 8-12 min with a sodium hydroxide solution, standing, separating the waste liquid, washing twice with a large amount of water, standing, separating the waste liquid, adding dry magnesium sulfate, stirring, opening a kettle bottom valve, placing a standing device spread with a filtering cloth, standing, carrying out filtering and packaging, and analyzing the content. According to the present invention, the production process has beneficial effects of process simplifying, production cycle shortening, energy consumption reducing and pollution reducing.
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Paragraph 0008-0009
(2019/07/10)
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- Synthetic method for organic intermediate di-tert-butyl peroxide
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The invention discloses a synthetic method for the organic intermediate di-tert-butyl peroxide. The synthetic method comprises the following steps: adding 2-methyl-2-propylamine and a potassium sulfate solution into a reaction vessel, controlling a stirring speed to be 110-130 rpm, controlling solution temperature to be 5-10 DEG C, adding aluminum isopropoxide, adding a diethylene glycol diethyl ether solution in batches within 30-50 min, and continuing a reaction for 90-120 min; and then adding nickel fluoride powder, controlling a stirring speed to be 220-250 rpm, continuing the reaction for2-4 h, carrying out standing for 30-50 min so as to allow the solution to be layered, carrying out washing with a sodium chloride solution for 30-40 min, then carrying out washing with a 1-pentanol solution for 20-40 min, carrying out recrystallization in a 2-hexanone solution, and then carrying out dehydration with a dehydrating agent so as to obtain the finished di-tert-butyl peroxide.
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Paragraph 0016; 0017; 0019-0020; 0024; 0025
(2018/07/30)
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- A method of preparing di-tert-butyl peroxide
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A method of preparing di-tert-butyl peroxide is disclosed and belongs to the technical field of organic synthesis. The method includes a step of adding tert-butyl alcohol and sulfuric acid into a first reaction device, reacting under stirring, and controlling the temperature and reaction time of the reaction under stirring in the first reaction device to obtain a tert-butyl hydrogen sulfate liquid, a step of adding a recovered mother liquor into a second reaction device, adding crude tert-butyl alcohol and the tert-butyl hydrogen sulfate liquid into the second reaction device, and controlling the temperature and reaction time of a reaction under stirring in the second reaction device to obtain a reaction product, a step of feeding the reaction product to a liquid separating tank, and performing liquid separating to obtain an upper oil phase that is the di-tert-butyl peroxide and a lower water phase that is a mother liquor adopted as a recovery mother liquor for a next turn of reactions. The method is simple and short in process steps, and can allow the content of the di-tert-butyl peroxide in the upper oil phase to be 97.5% or above, thus meeting requirements on industrial scaled-up production. The method avoids environment pollution, saves raw materials, reduces the cost and achieves circular economy.
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Paragraph 0020; 0022; 0024; 0026; 0028
(2017/02/24)
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- Oxidizing properties of the tert-butyl hydroperoxide-tetra-tert- butoxychromium system
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tert-Butyl hydroperoxide reacts with the tetra-tert-butoxychromium by oxidizing the latter to chromyl CrV=O (C6H6, 20 C). At t-BuOOH-Cr(OBu-t)4 ratio of 2: 1 or higher, oxygen is released. The occuring processes include the formation of chromium-containing peroxides and peroxytrioxydes. The t-BuOOH-Cr(OBu-t)4 system oxidizes aromatic hydrocarbons of various structures (anthracene, 9,10-dimethylanthracene, 1,1-diphenylethylene, alkylarenes), as well as primary and secondary alcohols. Depending on the structure of the substrate, the oxidants are: in situ generated oxygen including that in the singlet state, peroxy radicals, or chromium-containing peroxides.
- Stepovik,Potkina,Poddelskii
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p. 2005 - 2017
(2014/01/17)
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- Synthesis, single crystal structures and efficient catalysis for tetralin oxidation of two novel complexes of Cu(II) with 2-aminomethyl pyridine
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Two novel Cu(II) complexes were synthesized through the reaction of 2-aminomethyl pyridine (AMP) with CuCl2·2H2O by changing the metal/ligand ratio. Their structures were thoroughly characterized by FT-IR, elemental analysis and X-ray diffraction method. The results revealed that complex 1 [Cu(AMP)Cl2] consists of isolated binuclear molecules unit and displays distorted tetragonal pyramid. Complex 2 [Cu(AMP) 2(H2O)2]Cl2 exhibits a octahedral geometry. The complexes were both evaluated as catalysts in the tetralin oxidation with TBHP as oxidant. Complex 1 showed high catalytic activity and selectivity towards α-tetralone under mild conditions. Thus, under the optimized conditions (acetonitrile 10 ml, catalyst 0.045 mmol, tetralin 4.5 mmol, 65% TBHP 22.5 mmol, T = 50 °C), the conversion of tetralin reached 89% with a selectivity of 71% towards α-tetralone. Compared with complex 1, complex 2 displayed low catalytic activity mainly due to the strong steric hindrance from the two coordinated 2-aminomethyl pyridine molecules.
- Wang, Chunling,Zhang, Yuecheng,Yuan, Baoguo,Zhao, Jiquan
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scheme or table
p. 173 - 179
(2011/02/24)
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- Specific features of the reaction of vanadyl acetylacetonate with tert-butyl hydroperoxide
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Reaction of vanadyl acetylacetonate with tert-butyl hydroperoxide (benzene, 20°C) at any molar ratio leads to the elimination of ligand and its oxidation mainly to CO2 and acetic acid. At the (acac)2VO: t-BuOOH ratio above 1:10 liberation of oxygen partially in the singlet state takes place.
- Stepovik,Gulenova
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experimental part
p. 1663 - 1670
(2011/05/14)
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- System vanadium alkoxy compound-tert-butyl hydroperoxide-oxidant of hydrocarbon C-H bonds
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Vanadium alkoxy compounds [(t-BuO)4V, (t-BuO)3VO] react with tert-butyl hydroperoxide (C6H6, 20°C) to liberate oxygen, partly in the singlet form, and to form alkoxyl and peroxyl radicals via the intermediacy of vanadium peroxides and trioxide. These systems are capable of oxidizing hydrocarbon C-H bonds. The process is radical in nature and involves formation of carbon-centered radicals and their reaction with oxygen generated in the systems. Vanadium-containing peroxides, too, take part in the oxidation reaction.
- Stepovik,Gulenova,Tishkina,Cherkasov
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p. 1254 - 1262
(2008/03/12)
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- Preparation of dialkyl peroxides
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A process is disclosed for the preparation of a dialkyl peroxide comprising reacting one or more members selected from the group consisting of an alkylating alcohol of the formula ROH, and an olefin of the formula (R2)(R2a)C═C(R3)(R3a), wherein R is C1–C10 allyl, and R2, R2a, R3, and R3a are independently selected from hydrogen and C1–C10 alkyl; with a hydroperoxide of the formula R1OOH, wherein R1 is C1–C10 allyl; in the presence of an effective amount of a substantially solid, insoluble, heterogenous acidic catalyst; followed by separation of the reaction mixture from said catalyst; wherein said catalyst has readily available acidity for organic reactions and exists in the solid phase in the processes of the invention, while the reactants in those processes, by contrast, exist in the liquid and/or gaseous phase, whence the catalyst is referred to as heterogeneous.
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(2008/06/13)
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- Reaction of zirconium alkoxides with tert-butyl hydroperoxide. Oxidative ability of the Zr(OBu-t)4-t-BuOOH system
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Oxidation of the isopropoxy group in the Zr(i-PrO)4·i- PrOH complex involves both direct reaction with tert-butyl hydroperoxide and intermediate formation of zirconium peroxy compound. Zirconium tetra-tert-butoxide reacts with tert-bytyl hydroperoxide to form metal-containing peroxide and trioxide. Decomposition of the latter leads to oxygen evolution and is accompanied by radical formation. The alkoxyl and peroxyl radicals formed were identified by ESR spectroscopy. The nature of the oxidant (oxygen, zirconium-containing peroxide and-trioxide) in the Zr(OBu-t)4-t-BuOOH system is determined by the structure of the substrate molecule. Pleiades Publishing, Inc., 2006.
- Gulenova,Stepovik,Cherkasov
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p. 980 - 988
(2008/02/03)
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- Preparation of di-t-alkyl peroxides and t-alkyl hydroperoxides from n-alkyl ethers
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A process for production of a t-alkyl peroxide compound includes the steps of: a) reacting an n-alkyl t-alkyl ether with a reactant mixture comprising an acid catalyst and a compound of the formula RO2H??(I) ?where R is H or t-alkyl, provided that if R is t-alkyl the t-alkyl peroxide compound product is a di-t-alkyl peroxide, and b) isolating a reaction product comprising said t-alkyl peroxide compound from the mixture resulting from step a). The process can be used to prepare t-butyl hydroperoxide or di-t-butyl peroxide from methyl t-butyl ether. Sulfuric acid may be used as the acid catalyst.
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- The reactions of 3,6-di-tert-butyl-1,2-benzoquinone and 3,6-di-tert-butylcatechol with tert-butyl hydroperoxide
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Reaction of 3,6-di-tert-butyl-1,2-benzoquinone and 3,6-di-tert-butylcatechol with tert-butyl hydroperoxide in aprotlc solvents leads to the generation of semiquinone (SQ 'H), alkylperoxy (ROO'), and alkyloxy radicals. The reaction of SQ'H and ROO' produces 2,5-di-tert-butyl-6-hydroxy-1,4-benzoquinone, 3,6-di-tert-butyl-1-oxacyclohepta-3,5-diene2,7-dione, and 2,5-di-tert-butyl-3,6-dihydroxy-1,4-benzoquinone. The radical generated from solvent attacks SQ' H at position 4 with C-C bond formation. 4-Benzyl-2,5-di-tert-butyl-6-hydroxycyclohexa-2,5-diene-1-dione produced in this way is transformed into 4-benzyl-3,6-di-tert-butyl-1,2-benzoquinone under the reaction conditions.
- Glushakova,Skorodumova,Nevodchikov,Abakumova,Makarenko,Cherkasov,Druzhkov
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p. 934 - 937
(2007/10/03)
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- Ditertiary butyl peroxide preparation from tertiary butyl hydroperoxide
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Disclosed is a method of selective preparation of ditertiary butyl peroxide from tertiary butyl hydroperoxide and t-butanol which comprises reacting said tertiary butyl hydroperoxide and t-butanol over a solid acid catalyst selected from: a) an acidic montmorillonite clay; b) an acidic zeolite selected from the group consisting of dealuminized Y-zeolite and pentasil zeolite; c) an acidic organic resin; and d) heteropoly acids supported on an oxide selected from Group III or Group IV.
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- Ditertiary butyl peroxide preparation from tertiary butyl hydroperoxide
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Disclosed is a method of selective preparation of ditertiary butyl peroxide from tertiary butyl hydroperoxide and t-butanol which comprises reacting said tertiary butyl hydroperoxide and t-butanol over a Beta-zeolite catalyst under hydroperoxide conversion conditions.
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Reaction of alkyl hydroperoxides (1(ary), 2(ary) or 3(ary)) upon tertiary alkyl trichloroacetimidates under acidic catalysis yielded unsymmetrical dialkyl peroxides with yields in the range 30-70%.
- Bourgeois,Montaudon,Maillard
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p. 2477 - 2484
(2007/10/02)
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- ACID-CATALYZED DECOMPOSITIONS OF HYDROPEROXIDES IN THE PRESENCE OF KETONES
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Ketones and aldehydes accelerate decomposition of hydroperoxides in acetonitrile solution in the presence of strong acids.An explanation of the effect, due to the formation of semiperketals (semiperacetals) which undergo rapid acid-catalytic decomposition, is proposed.The macrostage character of the reaction of acid-catalyzed decomposition of cyclohexyl hydroperoxide was demonstrated for the first time.The initially slow decomposition takes place homolytically and yields the product cyclohexanone, which accelerates decomposition.
- Petrov, L. V.,Drozdova, T. I.,Lyuta, L. Ya.,Solyanikov, V. M.
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p. 226 - 232
(2007/10/02)
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- Detection of Alkylperoxo and Ferryl, (Fe(IV)=O)(2+), Intermediates during the Reaction of tert-Butyl Hydroperoxide with Iron Porphyrins in Toluene Solution
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PFeII and PFeIIIOH (P is a porphyrin dianion) catalyze the decomposition of tert-butyl hydroperoxide in toluene solution without appreciable attack on the porphyrin ligand. (1)H NMR spectroscopic studies at low temperature (-70 deg C) give evidence for the formation of a high-spin, five-coordinate intermediate, PFeIIIOOC(CH3)3.On warming this decomposes to PFeIIIOH (P = tetramesitylporphyrin, TMP) or PFeIIIOFeIIIP (P = tetra-p-tolylporphyrin, TTP) with the formation of (TMP)FeIV=O as an observed intermediate in the first case.Treatment of PFeIIIOOC(CH3)3 at -70 deg C with N-methylimidazole (MeIm) yields the intermediate (MeIm)PFeIV=O.Organic products formed from this reaction are tert-butyl alcohol, di-tert-butyl peroxide, benzaldehyde, acetone, and benzyl-tert-butyl peroxide, which arise largely from a radical chain process initiated by the iron porphyrin but continuing without its intervention.
- Arasasingham, Ramesh D.,Cornman, Charles R.,Balch, Alan L.
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p. 7800 - 7805
(2007/10/02)
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- RELATIVE YIELDS OF EXCITED KETONES FROM SELF-REACTIONS OF ALKOXYL AND ALKYLPEROXYL RADICAL PAIRS
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We have measured the ratios of excited ketones that arise from the self-reactions of alkoxyl (2R1R2CHO.) and peroxyl (2R1R2CHO. radicals.This was accomplished by measuring the chemiluminescence emission from solutions of R1R2CHO2H, or R1R2CH2 and O2, in the presence of a free-radical initiator trans-RON=NOR, in which R=t-Bu or R1R2CH in paired experiments.The excited states were trapped with 2-tert-butyl-9,10-dibromoanthracene or another fluorescent derivative of anthracene.The peroxyls were less efficient sources by 17percent, 48percent, and 42percent than the alkoxyls for the cases in which R1R2C=O was acetophenone in ethylbenzene, cyclohexanone in cyclohexane, and 1-tetralone in t-BuPh and in t-BuOH, respectively.The activation energy for formation of excited 1-tetralone (To and/or S1) from two 1-tetralylperoxyl radicals was 6 +/- 3 kcal/mol higher than for production of excited state from the corresponding pair of alkoxyl radicals.The results are consistent with but do not demand the hypotesis that excited carbonyl states arise in peroxyl terminations by way of alkoxyl pairs.
- Lee, S.-H.,Mendenhall, G. D.
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p. 4318 - 4323
(2007/10/02)
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- (17)O-ENRICHED HYDROGEN PEROXIDE AND T.BUTYL HYDROPEROXIDE: SYNTHESIS, CHARACTERIZATION AND SOME APPLICATIONS
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Solutions of (17)O-labelled hydrogen peroxide and t.butyl hydroperoxide in water or anhydrous solvents are easily obtained, starting from labelled oxygen.These stable enriched (17)O prducts are valuable reagents to synthesize various labelled molecules, which have been characterized by (17)O-NMR spectroscopy.Chemical shifts of several O-containing groups are given.
- Barieux, J.J.,Schirmann, J.P.
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p. 6443 - 6446
(2007/10/02)
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- Reactions of the 2,6-Di-tert-butyl-4-(N-tert-butylnitrono)-phenoxyl Radical
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The title compound, a phenoxyl radical containing a nitrono group, reacts with alcohols and tert-butylhydroperoxide yielding phenol and products of secondary solvent reactions.The reactions with lead tetraacetate, tert.-butoxy and 2-cyanoisopropyl radicals give high yields of cyclohexadienone adducts (6, 7 and 10) containing unchanged nitrono function.The reaction with dibenzoylperoxide, however, leads to the modification of the nitrono group yielding the N-benzoyloxycarboxamide (8).In the acidic decomposition of the tert-butoxy radical adduct we suggest a nitrenium ion (16) as an intermediate.
- Schulz, Manfred,Bach, Barbara,Reinhardt, Michael
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p. 579 - 587
(2007/10/02)
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- RATE CONSTANTS FOR THE FORMATION OF OXIRANES BY γ-SCISSION IN SECONDARY β-t-BUTYLPEROXYALKYL RADICALS
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Rate constants for the title reactions have been determined from the ratios of oxirane to peroxide obtained in the reductons of β-bromoalkyl t-butyl peroxides with tributyltin hydride.At ca. 298 K the rate constants are 0.32, 1.12, 1.96, 2.0 and 6.2E6 s-1 for β-t-butylperoxy derivatives of trinorbornan-2-yl (exo) cyclohexyl, 1-methylpropyl , cyclopentyl and 1-ethylbutyl, respectively.The results are discussed in terms of steric and electronic effects in the transition state leading to ring closure of the radicals.
- Bloodworth A. J.,Courtneidge, J. L.,Davies, Alwyn G.
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p. 523 - 528
(2007/10/02)
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- INVESTIGATIONS IN THE FIELD OF FUNCTIONAL ORGANIC PEROXIDES. XIII. CARBOXYL-CONTAINING DIALKYL PEROXIDES, THE MUTUAL EFFECT OF THE FUNCTIONAL GROUPS
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The induction and steric constants for tert-butylperoxy-containing substituents, calculated on the basis of kinetic investigation of the ionization and alcoholysis of tert-butylperoxy carboxylic acids and hydrolysis of their methyl esters, exceed the analogous values for the majority of related alkoxy-containing groups.The presence of the functional groups has an appreciable effect on the rate of thermal decomposition of the substituted peroxides.The steric factors, field effect, and intra- and intermolecular hydrogen bonds are significant.
- Rakhimov, A. I.,Baklanov, A. V.
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p. 476 - 480
(2007/10/02)
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- Catalysis by Phthalocyanines, XXVI. - Decomposition of Hydroperoxides on Iron and Cobalt Phthalocyanine
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The decomposition of 7-cumyl hydroperoxide and tert-butyl hydroperoxide on iron or cobalt phthalocyanine in 1-chloronaphthalene, 1-bromonaphthalene and 3-chlorotoluene proceeds with evolution of oxygen and according to second order kinetics (Figures 2 and 3; Tables 1 - 3 and 7); the yield of oxygen is not quantitative (Figure 1, Tables 1 - 3 and 7).Evolution of oxygen is not observed in 1-methylnaphthalene and decalin. - In the presence of N-(2-naphthyl)aniline the oxygen yield decreases with increasing concentration of the inhibitor (Table 4).The inhibitor efficiency is influenced by substituents in the phenyl group (Table 5), a Hammett relation being fulfilled in the case of 3-Cl and 4-Cl or CH3O (Figure 4). - 2-Benzyl-2-propyl hydroperoxide decomposes without evolution of oxygen.The decomposition rate on cobalt phthalocyanine is influenced by the composition of the solvent systems (1-chloronaphthalene/decalin, 1-chloronaphthalene/3-chlorotoluene, 3-chlorotoluene/decalin) (Table 6). - The mechanism of the decomposition of the hydroperoxides, especially the stabilizing reactions of the radicals, and the attack of the inhibitors is discussed in the light of previous results.
- Kropf, Heinz,Spangenberg, Jochen,Gunst, Andreas,Hinrichsen, Jens
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p. 1923 - 1938
(2007/10/02)
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- Chemiluminescence in the Reaction of a Sulfurane with Alkyl Hydroperoxides
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The reaction of Martin's sulfurane 1 with tert-butyl hydroperoxide, in the presence of 9,10-dibromoanthracene, emits light in two stages.The early stage, beginning on warming to about -40 deg C, coincides with the formation of olefin, and is intensified by degassing and quenched by oxygen or by organic sulfides.The later stage, seen on warming from -20 to -10 deg C, occurs during the formation of acetone from the hydroperoxide; this luminescence is eliminated by degassing and quenched by 2,6-di-tert-butyl-p-cresol and organic sulfides.Similar phenomena are observed with cumyl hydroperoxide.Relevant observations are reported on the NMR shifts produced in alcohol proton signals by diphenyl sulphoxide and dimethyl sulfoxide and on the CIDNP signals occurring during the reaction.Some conclusions are drawn concerning the mechanism of the luminescence.
- Bartlett, Paul D.,Aida, Tetsuo,Chu, Hsien-Kun,Fang, Tai-Shan
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p. 3515 - 3524
(2007/10/02)
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- Process for the preparation of n-alkyl-substituted hydroxypolyalkoxymethylcyclohexanes
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Non-ionic biodegradable detergents as exemplified by n-alkyl-substituted hydroxypolyalkoxymethylcyclohexanes may be prepared by condensing butadiene with allyl alcohol, selectively hydrogenating the resulting compound to form hydroxymethylcyclohexane, ring alkylating said substituted cyclohexane with an olefin in the presence of a free-radical generating compound to form an alkyl-substituted hydroxymethylcyclohexane and thereafter alkoxylating this compound to form the desired product.
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