5593-75-9

Upstream product

• 459-64-3 4-methoxybenzenediazonium tetrafluoroborate 
• 120-80-9 benzene-1,2-diol 
• 54737-34-7 4-(N,N-dimethylamino)phenoxyl radical 
• 105868-72-2 trolox c radical 
• 154286-48-3 C₇H₈NO 
• 147506-92-1 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl 
• 254428-58-5 2-hydroxyphenyl nitrite 

Downstream Products

• 120-80-9 benzene-1,2-diol 
• 154286-48-3 C₇H₈NO 
• 105868-72-2 trolox c radical 
• 54737-34-7 4-(N,N-dimethylamino)phenoxyl radical 
• 39075-90-6 2-butoxyphenol 
• 254428-58-5 2-hydroxyphenyl nitrite 
• 583-63-1 ortoquinone 

Relevant academic research and scientific papers

The effect of the medium polarity on the mechanism of the reaction of hydroxybenzenes with hydrazyl radical in aprotic solvents

Mechanisms of the reaction of di- and trihydroxybenzenes with 2,2′-diphenyl-1-picrylhydrazyl (stable radical) in aprotic media of different polarity have been elucidated by experimental and quantum-chemical methods. Kinetic, stoichiometric, and activation

Myricetin, rosmarinic and carnosic acids as superior natural antioxidant alternatives to α-tocopherol for the preservation of omega-3 oils

22 natural polyphenols are compared to 7 synthetic antioxidants including BHT, BHA, TBHQ and PG with regard to their ability to protect omega-3 oils from autoxidation. The antioxidant efficiency of phenols is assessed using the DPPH test and the measurement of oxygen consumption during the autoxidation of oils rich in omega-3 fatty acids. Also, the bond dissociation enthalpies (BDE) of the Ar-OH bonds are calculated and excellent correlations between thermodynamic, kinetic and oxidation data are obtained. It is shown that kinetic rates of hydrogen transfer, number of radicals scavenged per antioxidant molecule, BDE and formation of antioxidant dimers from the primary radicals play an important role regarding the antioxidant activity of phenols. Based on this, it is finally shown that myricetin, rosmarinic and carnosic acids are more efficient than α-tocopherol and synthetic antioxidants for the preservation of omega-3 oils.

The chain-breaking antioxidant activity of phenolic compounds with different numbers of O-H groups as determined during the oxidation of styrene

The technique based on monitoring oxygen, consumption was applied to test 18 polyphenols (PP) and model phenolics as a chain-breaking antioxidant during the oxidation of styrene initiated by 2,2′-azobis(2,4- dimethylvaleronitril) at 37°C. The chain-breaking capability of PP was characterized by two parameters: the rate constant k1 for the reaction of antioxidants with the peroxy radical produced from styrene and the stoichiometric coefficient of inhibition, f, which shows how many kinetic chains are terminated by one molecule of PP. Rate constants k1 × 105 (in M-1 s-1) were found to be 10 (catechol), 27 (pyrogallol), 34 (3,6-di-tert-Bucatechol), 4.3 (protocatechic acid), 12 (gallic acid), 15 (caffeic acid), 1 increases when going from one to two and three adjacent O-H groups in a benzene ring (catechol and pyrogallol derivatives, respectively). At the same time, two O-H. groups in metaposition in a A-ring of flavonoids actually do not participate in the inhibition. For the majority of PP, f is near to 2 independent of the number of OH groups. The correlation of k1 with the structure of PP and the O-H bond dissociation enthalpy has been discussed.

Infrared spectrum of 2-hydroxyphenoxyl radical and photoisomerization between trans and cis 2-hydroxyphenyl nitrites

Photoreaction of 2-nitrophenol has been investigated by low-temperature matrix-isolation IR spectroscopy and density-functional-theory (DFT) calculation. A reaction intermediate was identified as syn-trans 2-hydroxyphenyl nitrite, and the reaction product caused by dissociation of NO from the intermediate as 2-hydroxyphenoxyl radical. Both syn-trans and syn-cis 2-hydroxyphenyl nitrite isomers were produced by recombination of 2-hydroxyphenoxyl radical with NO in annealing at 27 K after the UV irradiation. The conformational change from cis to trans around the O-N axis occurred upon visible-light irradiation. The rate constants of photoreaction were determined by a least-squares fitting of the changes in the IR band intensities.

Kinetic and thermodynamic parameters for the equilibrium reactions of phenols with the dpph. radical

The kinetics and energetics of the reversible reaction of phenols with the dpph. radical have been studied; steric shielding of the divalent N by the o-NO2 in dpph. seems to be the main cause of the entropic barriers of this reaction. The Royal Society of Chemistry 2006.

Electron-Transfer Reaction of Cinnamic Acids and Their Methyl Esters with the DPPH. Radical in Alcoholic Solutions

The kinetic behavior of cinnamic acids, their methyl esters, and two catechols 1-10 (ArOH) in the reaction with DPPH. in methanol and ethanol is not compatible with a reaction mechanism that involves hydrogen atom abstraction from the hydroxyl

O-H Bond dissociation enthalpies in hydroxyphenols. A time-resolved photoacoustic calorimetry and quantum chemistry study

Time-resolved photoacoustic calorimetry (TR-PAC) was used to investigate the energetics of O-H bonds of phenol, catechol, pyrogallol, and phloroglucinol. Values of -27.1 ± 3.9, -44.1 ± 4.4 and -1.6 ± 3.8 kJ mol-1, respectively, were obtained fo

Kinetics and mechanisms of reactions of the nitrate radical (NO 3) with substituted phenols in aqueous solution

Second order rate constants were obtained for the reactions of the nitrate radical (NO3) with substituted phenols in aqueous solutions at 298 K and pH = 0.5. The following compounds were investigated and the corresponding rate constants are rep

Diphenol radical cations and semiquinone radicals as direct products of the free electron transfer from catechol, resorcinol and hydroquinone to parent solvent radical cations

In the pulse radiolysis of solutions of catechol, resorcinol and hydroquinone in n-butylchloride, dihydroxybenzene radical cations (40%) as well as semiquinone radicals (60%) are observed as direct synchronously formed products of the electron transfer from the solvent parent ions to the solute. This is explained in terms of free electron transfer succeeding in nearly every encounter of the reactants, which in the case of the studied dihydroxybenzenes involves femtosecond molecular dynamics effects. The rotation of the C-OH bond causes cycling of the molecule through transient conformations also exhibiting different electron distributions. From the more chemical point of view, the diphenol radical cations represent the first and till now unknown intermediates of oxidative semiquinone radical formation.

Naphthalene diols: a new class of antioxidants intramolecular hydrogen bonding in catechols, naphthalene diols, and their aryloxyl radicals.

1,8-Naphthalenediol, 5, and its 4-methoxy derivative, 6, were found to be potent H-atom transfer (HAT) compounds on the basis of their rate constants for H-atom transfer to the 2,2-di(4-t-octylphenyl)-1-picrylhydrazyl radical (DOPPH*), k(ArOH/DOPPH)*, or as antioxidants during inhibited styrene autoxidation, k(ArOH/ROO)*, initiated with AIBN. The rate constants showed that 5 and 6 are more active HAT compounds than the ortho-diols, catechol, 1, 2,3-naphthalenediol, 2, and 3,5-di-tert-butylcatechol, 3. Compound 6 has almost twice the antioxidant activity, k(ArOH/ROO)* = 6.0 x 10(6) M(-)(1) s(-1), of that of the vitamin E model compound, 2,2,5,7,8-pentamethyl-6-chromanol, 4. Calculations of the O-H bond dissociation enthalpies compared to those of phenols, (deltaBDEs), of 1-6 predict a HAT order of reactivity of 2 alpha(ROO)* = 0.32, gave the expected order, since the ROO* reaction is more exothermic than the DOPPH* reaction. Compound 6 is sufficiently reactive to react directly with oxygen, and it lies off the log k(ArOH/ROO)* versus deltaBDE plot.