Butyl Peroxide Research Articles

ChemInform Abstract: Conversions of Triethoxymethane in the Presence of tert. Butyl Peroxide by Photochemical Initiation.

ChemInform Abstract: Conversions of Triethoxymethane in the Presence of tert. Butyl Peroxide by Photochemical Initiation.

ChemInform Abstract: Copper Catalyzed Reactions of Di‐tert‐butyl Peroxide: Oxidative Carbonylation of Alcohols to give Dialkyl Carbonates, Oxalates, or Succinates.

AbstractThe dialkyl carbonates (IV) and/or the dialkyl oxalates (VI) are synthesized from the alcohols (I) and carbon monoxide (II) using di‐tert‐ butyl peroxide (III) as an oxidant.

Detection of picomole levels in lipid hydroperoxides by a chemiluminescence assay.

A highly sensitive and simple chemiluminescent method for the quantitation of lipid hydroperoxides at the picomole level is described. The method is based on detecting the chemiluminescence generated during the oxidation of luminol by the reaction with hydroperoxide and cytochrome c under mild conditions. A semilogarithmic relationship was observed between the hydroperoxide added and the chemiluminescence produced. For lipid hydroperoxides, cytochrome c was a most favorable catalyst for generating the chemiluminescence, rather than cytochrome c heme peptide and horseradish peroxidase. This method had high sensitivity to methyl linoleate hydroperoxide, arachidonic acid hydroperoxide and cholesterol hydroperoxide, but low to /-butyl hydroperoxide, J-butyl perbenzoate, diacyl peroxides (lauroyl peroxode and benzoyl peroxide) and dialkyl peroxides (di-/-butyl peroxide and dicumyl peroxide).

ChemInform Abstract: Oxidation of Alcohols and Diols by Ti(O ‐ iPr)4 ‐ tBu ‐ OOH System.

AbstractThe alcohols (Ia)‐(Id) are oxidized by tert.‐butyl peroxide in the presence of catalytic amounts of Ti(IV)‐isopropoxide to give the corresponding ketones (II).

Photoinduced electron-transfer reactions of 2(3H)-furanones and bis(benzofuranones). Spectral and kinetic behavior of radicals and radical cations

The spectral and kinetic behaviors of radical cations produced under efficient electron-transfer quenching of 1,4-dicyanonaphthalene or 9,10-dicyanoanthracene singlet by a number of 2(3H)-furanones and bis(benzo-furanones) have been examined by nanosecond laser flash photolysis (337.1 and 425 nm). The efficiencies of net electron transfer in the course of quenching processes are moderately high (0.2-0.6) in acetonitrile. The radical cations from bis(benzofuranones) several 2(3H)-furanones containing a benzyl group at the 3-position undergo fragmentation to benzofuranoxy and furanoxy radicals (+ benzyl or benzofuranoyl carbocations) with rate constants of 0.3 x 10W s . The long-lived furanoxy radicals, independently generated via hydrogen abstraction by tert-butoxy radicals from 2(5H)-furanones and 3-phenyl-2(3H)-benzofuranone, as well as via direct photolysis of 3-benzoyl-3,5-diphenyl-2(3H)-furanone, are characterized by sharply structured absorption spectra and relatively slow second-order decay kinetics (6-8 x 10Y M s in 1:2 benzene-di-tert butyl peroxide, v/v). 28 references, 7 figures, 3 tables.

Radical telomerization of ethylene by triethylsilane initiated by Mn2(CO)10 or butyl peroxide

Complexes of triethylsilane with Mn2(CO)10 are effective hydrogen transfer agents in the step involving chain transfer at the Si-H bond in radical telomerization.

The addition of methyl radicals to hexafluoroacetone

AbstractThe reaction of methyl radicals (Me) with hexafluoroacetone (HFA), generated from ditertiary butyl peroxide (dtBP), was studied over the temperature range of 402–433 K and the pressure range of 38–111 torr. The reaction resulted in the following displacement process taking place: magnified image where TFA refers to trifluoroacetone. The trifluoromethyl radicals that were generated abstract a hydrogen atom from the peroxide: equation image such that k6a is given by: where θ = 2.303RT kcal/mol. The interaction of methyl and trifluoromethyl radicals results in the following steps: equation image Product analysis shows that k17/kk = 2.0 ± 0.2 such that k17 = 1010.4±0.5M−1 · s−1. The rate constant k5 is given by: It is concluded that the preexponential factor for the addition of methyl radicals to ketones is lower than that for the addition of methyl radicals to olefins.

The effect of diethylphosphite and of diethylphosphine oxide on polydimethylvinylsiloxanes

A study has been made of the effect of diethylphosphite and diethylphosphine oxide on various polydimethylvinylsiloxanes in the presence of peroxide initiators, platinum catalysts and UV-irradiation. It was found that reactions of polydimethylvinylsiloxanes with diethylphosphite and diethylphosphine oxide in the presence of peroxide initiators (benzoyl peroxide and tertiary butyl peroxide) and platinum catalysts (Pt: C and H 3PtCl 6·6H 2O) and azoisodibutyronitrile (ABN) are unaccompanied by phosphorylation of polydimethylvinylsiloxanes at high temperatures. It is only by UV-irradiation that partial phosphorylation of polydimethylvinylsiloxanes with diethylphosphine oxide takes place, though the process is a very complex one.

Stereoselective nucleophilic addition reactions to nitro sugars

Nucleophile(s) almost exclusively added from the equatorial side of 2-nitro-β- D -2-enopyranoside and the axial side of 2-nitro- D - ribo -1-enitol. On the other hand, methoxide and tert -butyl peroxide ions approached from the equatorial side of 2-nitro-α- D -2-enopyranoside, whereas methanol and hydrogen peroxide ion from the axial side.

Metering of peroxidic polymerization initiators at elevated pressure

AbstractMetering of polymerization initiators, which has to take place at relatively low temperatures to prevent premature decomposition, involves the risk of the initiators crystallizing out at the high pressures involved. For this reason, the solubility of different peroxides, which are highly efficient initiators for radical chain polymerization, was investigated in isododecane and other commonly used solvents. The measurements were carried out at temperatures of −30 to +40°C and pressures up to 3000 bar in ranges of concentration between 50 and 100 wt.‐%. It was found that both tert.‐butyl perpivalate and tert.‐butyl perbenzoate, and to a lesser extent, di‐tert. ‐butyl peroxide, need to be diluted in order to avoid undesirable precipitation of solids. A substantial improvement in the solubility of the peroxides examined could be achieved by replacing the tertiary butyl group with a tertiary amyl group. On the basis of the solubility values determined, recommendations are made on the necessary dilution of the peroxides and the choice of solvent.

Copolymerization of dimethylvinylethynylmethyl-tert.-butyl peroxide with vinyl monomers

The kinetics of the early stages of free-radical copolymerization of dimethyl-vinylethynylmethyl-tert.-butyl peroxide with vinyl monomers, as a special case of inhibited polymerization, are discussed. The possible separate reaction stages are put forward and equations for the rate of the process are derived, based on the assumption that termination of the polymeric free radicals occurs predominantly by chain transfer to the peroxidic monomer. The experimental results presented indicate that this assumption is justified at concentrations of the peroxidic monomer from 20 to 100 moles % in the mixture, and the proposed rate equation describes the process satisfactorily in that range of concentrations. This confirms the conclusion drawn previously that dimethylvinylethynylmethyl-tert-.butyl peroxide has a weak inhibiting effect. Correlation equations relating the rate constants of transfer to the peroxidic monomer, to the Q and e values of vinyl monomers were found.

On the synthesis and some properties of water soluble polymeric peroxides

A study has been made of the copolymerization of acrylic acid (AA) with a peroxide monomer, dimethylvinylethynylmethyl-tert.-butyl peroxide (VEP) in methanol solution. The copolymerization constants have been determined ( r AA = 0·19 ± 0·03 and r VEP = 1·40 ± 0·10). It is shown how the copolymerization rate rises as the VEP concentration in the monomer mixture is increased. It was found that the neutralization of carboxyl groups leads to the obtained copolymers becoming soluble in aqueous media, when the minimal concentration of carboxylate units amounts to 54·6 mole%. It is shown that the water soluble polymeric peroxides (WPP) posses surfactant properties. Values of the critical concentration of WPP micelle formation have been found, and it is shown that these values are determined by the composition and molecular weight of the WPPs.

Effect of Peroxide Administration on Selenium Utilization, Growth, Deficiency Symptoms, and Glutathione Peroxidase Activity in Chicks Fed Controlled Selenium Diets ,

The effect of peroxide administration on chick growth, severity of exudative diathesis, and glutathione peroxidase activity was determined. Hydrogen peroxide reduced rate of growth and usually reduced glutathione peroxidase activity of liver and plasma. The severity of exudative diathesis was greatly influenced by dietary selenium level but we found little if any relationships of this disease to peroxide induced reductions in glutathione peroxidase activity. Neither ethoxyquin nor excess supplemental selenium were effective in reversing the peroxide toxicity. The effect of hydrogen peroxide in reducing enzyme activity was related to decreased selenium uptake and retention.Tertiary butyl peroxide administration caused a more serious depression in enzyme activity of liver than hydrogen peroxide. This organic peroxide caused a small, but non-significant, reduction in selenium retention.

The reactions of methyl radicals with chloromethanes

AbstractThe reaction of methyl radicals with CCl4 and CCl3Br have been reinvestigated in the gas phase over a wide range of temperatures and pressures using both the photolysis of acetone and the pyrolysis of di‐tertiary butyl peroxide (dtBP) as the methyl radical sources. The results are in essential agreement with previous work; however, these new studies provide evidence that at higher pressures the major source of HCl in the reactions is due to methyl radical attack on CH3CCl3, formed via the combination of methyl and trichloromethyl radicals.From these investigations Arrhenius parameters for the reactions equation image have been determined: Pyrolysis of dtBP in the presence of relatively high‐pressure mixtures of CCl4 and CCl3Br resulted in no enhanced methane formation, since, under these conditions, the only termination product is C2Cl6, and the HCl precursor CH3CCl3 is not formed. A competitive technique has been used in which dtBP was pyrolysed in the gas phase in the presence of high‐pressure mixtures of CCl3Br and a chloromethane. Arrhenius parameters were obtained for the reactions equation image and the results were used to provide information on the importance of polar effects for hydrogen abstraction from halogenated methanes.

Acroleindiethylacetal: Reaction with free radicals and copolymerization

AbstractThe reaction between acroleindiethylacetal (3.3‐diethoxypropene) and free radicals and the behaviour of this acetal in the free radical copolymerization with unsaturated monomers has been investigated. The decomposition of benzoyl peroxide and tert.‐butyl peroxide in acroleindiethylacetal has been studied in the liquid phase. On the basis of the obtained products a mechanism is proposed which involves the abstraction of a hydrogen atom by a primary radical from a carbon atom which is adjacent to oxygen. We also tried to copolymerize the acetal with several conventional comonomers but copolymers were only obtained when acrylonitrile and maleic anhydride were used. The remarkably uniform composition of the copolymers from the acetal and maleic anhydride is explained through a donor‐acceptor complex between the two monomers.

Homolytic reactions of dibutyl ether with dialkylmaleates

1. α-Butoxybutyl radicals, formed during the reaction of dibutyl ether with tertiary butyl peroxide are effectively decomposed at a temperature >120°C to butyl radicals and butanal. 2. The homolytic reaction of dibutylether with dialkylmaleates leads primarily to the formation of dialkylesters of butylsuccinic and butanoylsuccinic acids. Dibutylether reacts analogously with diethylfumarate.

The synthesis and polymerization of vinyl silanes possessing two functional groups on the silicon atom

The radical polymerization of methylvinyl dialkoxy-(aryloxy, acetoxy) silanes has been investigated in the presence of di-tert.-butyl peroxide; the stronger electron accepting properties of the organo-hydroxy substituents have been found to increase the rate of polymerization. The rate constants of vinylsilane polymerizations have been calculated and brief characteristics of the produced polymers are given.

Reactivity and selectivity in light-induced free radical reactions of 2-propanol with purine and pyrimidine mononucleotides and dinucleoside monophosphates

Photoalkylation reactions with 2-propanol, initiated with di-tert-butyl peroxide, of a variety of purine and pyrimidine mononucleotides and dinucleoside monophosphates lead to the substitution of an alpha-hydroxyisopropyl group for the H-8 atom of adenosine and the addition of the alcohol across the 5,6-double bond of the pyrimidines. Adenosine moieties blocked at their 3'-hydroxyl group are alkylated faster than those blocked at their 5'-hydroxyl. The reactivity of the uridine moieties of 3'-UMP, 5'-UMP, and uridylyl-(3',5')-uridine is not affected by the location of the phosphate group. However, the uridine moiety of uridylyl-(3',5')-adenosine is modified faster than that of adenylyl-(3',5')-uridine. It is suggested that steric hindrance imposed by the phosphate group determines the reactivity of adenosine moieties, while base stacking involving adenosine determines the reactivity of uridine moieties. These two effects play a major role in controlling the nature and degree of the selectivity of these photoalkylation reactions for either adenosine or uridine. Cytidine has been found to be inert in these reactions.

The Thermal Decomposition of Cyanodiphenylmethyl t-Butyl Peroxide An Example of C–O Bond Scission

Abstract The thermal decomposition of cyanodiphenylmethyl t-butyl peroxide was investigated. The peroxide is abnormally stable and decomposes slowly at 130–135 °C, and the main reaction product is tetraphenylsuccinonitrile. A main reaction path including the C–O bond scission, in contrast to the case of triphenylmethyl t-butyl peroxide, is proposed.

The Photo-induced Addition of Acetic Acid to Olefins

The photo-induced addition of acetic acid to ethylene gave butyric acid. Small amounts of hexanoic, octanoic, 2-ethylbutyric, and 2-ethylhexanoic acids, and neutral substances were also formed. The presence of a small amount of di-tert. butyl peroxide was effective to form butyric acid. Main neutral substances were dibutyl and di (2-ethylhexyl) phthalates. A straight-chain saturated fatty acid was also obtained in an excellent conversion of a 1-olefin by the photo-induced addition of acetic acid to the 1-olefin [acetic acid : 1-olefin, 200 : 1 (mol)]. It was assumed that a ketone and an ester (s) were present in the by-products.