Phenolic studies

Deichmann WB. 1944. Phenol studies. V. The distribution, detoxification, and excretion of phenol in the mammalian body. Arch Biochem 3 345-355. 

Deichmann WB, Witherup S. 1944. Phenol studies. VI The acute and comparative toxicity of phenol and o-, m-, and/ -cresols for experimental animals. J Pharmacol Exp Ther 80 233-240. 

Deichmann WB, Kitzmiller KV, Witherup BS. 1944. Phenol studies. VII. Chronic phenol poisoning, with special reference to the effects upon experimental animals of the inhalation of phenol vapor. Am J Clin Pathol 14 273-277. 

Removal rates greater than 90% were observed for all of the phenols studied. The decay kinetics for phenol p-methoxyphenol p-cresol p-fluo-rophenol p-chlorophenol p-bromophenol 4-hydroxyacetophenone a,a,a-trifluoro-p-cresol p-cyanophenol and p-iodophenol were found to be consistent with the Langmuir-Hinshelwood kinetic model. After employing all the substituents, little variation on the Langmuir-Hinshelwood kinetic parameters was observed. 

Hammett correlations were developed from experimental data for substituted phenols studied under the UV/Ti02 process (D Oliviera et al., 1993). The mechanism for this reaction is understood to proceed via the hydroxyl radical. Experimental data from the study of dichlorophenols and trichlo-rophenols under UV/Ti02 were used for QSAR analysis (D Oliviera et al., 1993). Figure 9.13 demonstrates the QSAR model for substituted phenols formulated from experimental data. The QSAR model developed for substituted phenols shows a goodness of fit of 0.9766. A good correlation was also established for substituted phenols using Hammett s constant, o the correlation coefficient is 0.987 (D Oliviera et al., 1993). Similar correlation coefficients for the constants o and ores demonstrate that the descriptor ores can be used to accurately predict kinetic rate constants for substituted phenols. 

Reviewed previous SCWO research with model pollutants and demonstrated that phenolic compounds are the model pollutants studied most extensively under SCWO conditions Studied supercritical water oxidation of aqueous waste Explored reaction pathways in SCWO of phenol Studied catalytic oxidation in supercritical water Explored metal oxides as catalysts in SCWO Studied decomposition of municipal sludge by SCWO Investigated the SCWO kinetics, products, and pathways for CH3- and CHO-substituted phenols Determined oxidation rates of common organic compounds in SCWO... 

A similar effect of pH on dissolution rates of Mn(III/IV) oxides was observed by Stone (1987b) with substituted phenols. In this study, phenols with alkyl, alkoxy, or other electron, donating substituents were more slowly degraded. Stone (1987b) even found that p-nitrophenol, the most resistant phenol studied, reacted slowly with Mn(III/IV) oxides. 

For convenience we have normalized the results to pentachlorophenol. These results indicate that, in general, isopropanol is about two orders of magnitude less efficient a quencher than phenols and that pentachlorophenol is better than the other two phenols studied. Knowledge of these relative rate constants is important to the CIDNP studies on the photoreduction of ketones. 

Rates of quenching of excited state triplets have been measured and the influence of substituents on the phenols studied has shown that electron-donating substituents enhance the degradation process (< > 0.5) while phenol itself has a quantum yield for disappearance of only 0.1. 

In DPP, after application of the pulse, the potential returns to a continually increasing value, which eventually is sufficient to cause electrolysis during the nonpulse part of the experiment. Therefore, DPP does not have the advantage of restricted electrolysis times seen for normal-pulse polarography (NPP). Besides its application to trace analytical work, DPP can be advantageous because of the better resolution inherent in a peak-shaped output. The reaction of iron-sulfur protein site analogues [Fe S (SR)4] , with electrophiles is studied by DPP, where closely spaced reduction waves of the reactant and product are adequately resolved". The reduction of cobaltocene in the presence of phenol studied using DPP, allows quantitative measurement of the amount of cyclopentadienylcobalt cyclopentadiene produced in the electrolysis at the dme by" ... 

Glutaraldehyde cross-linking onto phenol- Study of the action of the active immobilized 745 On 00... 

The formation of phenoxy radicals upon oxidation from substituted phenols has been studied by the ESR technique, using nitrosodurene as spin trap [52]. Chloro(5,10,15,20-tetraphenylporphyrinato)cobalt(III) and its Ti-cation radical were used to promote the reaction. The phenols studied reacted with the cation radical but some of them interacted only with the complex. The reaction is pictured as involving electron transfer from the phenolate, mediated by an axially coordinated chloro ligand. 

Picosecond studies of the dimethyltetrazine dimer, and the benzene/phenol dimeric have also appeared. The dimethyltetrazine dimer study simply reports an IVR time of 35 ps for the 6a vibronic state. This result is in reasonable agreement with the linewidth estimated from spectroscopic data. The benzene/phenol study reports the rate of complex disappearance following single vibronic level excitation. This rate is found to increase with excitation energy above 1275 cm". ... 

Singh U, Bank A, Priyadarsini KI (2009) Reactions of hydroxyl radical with bergenin, a natural poly phenol studied by pulse radiolysis. Bioorg Med Chem 17 6008-6014... 

At least three different mechanisms contribute to the oxidation of the phenols studied ... 

In solid polystyrene at 343 K, this ratio for the phenols studied changes 17-fold, whereas in the liquid phase the rate constant of the reaction R02 + InH in ethylbenzene for the same compounds changes from 0.3 to 48-10 l/(mol s), i.e.., 160-fold. The rate constants of the reaction of R02- with several phenols (measured by the kinetics of the initiated oxidation of isotactic polypropylene (PPI)) change twofold (388 K), whereas in cumene at 333 K for the same phenols they change 20-fold. 

In acid solution aromatic amines form resins with formaldehyde. This reaction in olves the formation of nuclear methylene linkages similar to those which occur in phenol-formaldehyde resins. The reaction type characteristic of the aromatic nucleus rather than of the activating amine group, whose presence merely facilitates reaction. As a result, resins can be obtained even with tertiary amines such as dimethylaniline. Under these conditions the amine reacts as an ammono-phenol. Studies of the mechanism by which formaldehyde reacU with X-alkyl anilines in acid elution indicate that the primary reaction involves the nitrogen atom. 

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