With n-BuLi/t-BuOK (Lochmann's base), protons are removed from the hydroxyl and methyl groups of cresols to give cresol dianions in yields of 85% (o), 95% (m), and 40% (p). These dianions react with alkyl halides, MeSiCl, Bu₃Sn Cl, CO₂, and oxidizing agents at carbon only, and with dialkyl sulfates at both carbon and oxygen. Thus phenol derivatives bearing primary alkyl groups can be prepared from the corresponding methylphenol via cresol dianions. Dimethylphenol trianions were prepared with Lochmann's base from all six isomers of dimethylphenol. 3,5-Dimethylphenol trianion was prepared in the best yield (80%); 2,3-, 2,4-, 2,5-, 2,6-, and 3,4-dimethylphenol trianions were prepared in 19.5%, 19%, 52%, 36%, and 44% yields, respectively. The common side products were dianions and tetraanions (in the latter, the fourth proton was usually pulled from the ring ortho to oxygen). These trianions were reacted with dimethyl sulfate to give anisole derivatives. 3,5-Dimethoxytoluene monoanion was reacted with n-BuBr to give a mixture of O,O'-dimethylolivetol (40%) and 4-butyl-3,5-dimethoxytoluene (34%).

The removal of phenols from the waste waters of wood preserving plants has always presented problems. The purpose of this paper is to investigate the possibility of employing a biological system to reduce the phenol content of effluent from these plants.

Life supporting biological membranes are barriers to toxic chemicals. One of the factors determining the toxicity of chemical compounds is their distribution between membranes and their an environment. An octanol-water system is frequently used as a model for biological membranes to estimate the toxic potency of environmental pollutants. The distribution of a chemical between the octanol and the water phase is described by the octanol-water partition coefficient Kow. This study is concerned with the relationship between Kow and the molecular structure of the toxic chemical. In the study the following trihalophenols were included: 2,4,6-trifluorophenol (TriFP), 2,4,6-trichlorophenol (TriCP); 2,4,6-tribromophenol (TriBP) and 2,4,6-triiodophenol (TrilP). The distribution of halophenols between octanol and water was measured as a function of the pH. Experimental results were analyzed in terms of a two compartment distribution model which accounts for the pH dependent dissociation of the trihalophenol. We showed that, with the exception of TriIP, the pH dependence of the distribution coefficient of 2,4,6 trihalophenols can be understood with this model. From the fit of the distribution model to the experimental results, the following log(Kow) of the neutral molecules were determined: 1.96 (TriFP), 3.65 (TriCP}, 4.11 (TriBP) and approximately 4.42 (TrilP). For the ionized species the log(Kow) are 1.38 (TriFP), 0.15 (TriCP), 0.08 (TriBP) and 1.16 (TriIP). In relation with these distribution studies, the following values for the dissociation constants pKa were obtained: 7.12 (TriFP}, 6.15 (TriCP), 5.9 (TriBP) and 6.6 (TriIP). We also found that octanol dissolved in the water phase does not significantly affect the dissociation of TriIP. The relationship between Kaw and trihalophenol molecular structure was studied in two models. Linear relationships were found between log(Kow) and the surface area as well as between log(Kow) and molar volume for both the neutral and the ionized halophenols. It was not possible to discriminate between the two models. Distribution coefficients of the ionized and unionized 2,4,6-trihalophenols are proportional to the each other. The proportionality factor, (3.54±1.49)x104, is a measure of the effect of electric charge on the transfer across the water-octanol interface.

The accumulation of xenobiotics, such as halogenated phenols, in soils, sediments, and living organisms is primarily a partitioning process between an aquatic and organic phase. It is traditional to use a bulk octanol-water system to model the partitioning of a compound between complex biological lipid membranes and aqueous media. The octanol-water partition coefficient Kow successfully approximates the lipid membrane-water partition coefficient Ki;pw of neutral compounds. However, the ionized species of substituted phenols were shown (Smejtek, et al. 1993; Escher, et al. 1996) to have a higher affinity for lipid membranes than predicted from octanol-water results. Data on the octanol-water partition coefficients of molecular ions is limited. In order to compare the partitioning of neutral and charged species of halogenated phenols between the lipid membrane-water and octanol-water systems, we measured the pH dependent distribution of ionized and neutral 2,3,4,6-tetrachlorophenol (TeCP), pentafluorphenol (PFP), pentachlorophenol (PCP), and pentabromophenol (PBP). For the neutral (HA) species of each phenol, log Kow was found to be 4.28 (TeCP), 2.79 (PFP), 4.77 (PCP), and approximately 4.67 (PBP). For the ionized (A-) species of each phenol, log Kow was found to be 0.48 (TeCP), -0.85 (PFP), 1.16 (PCP), and 1.77 (PBP). These results are compared with sorption data on halophenols in a lipid membrane-water system (Smejtek, et al. 1996). This study shows that ionized halophenols have an affinity for lipid membranes about two to three orders of magnitude greater than for octanol. The usefulness of the octanol-water model as a predictor of lipid membrane-water partitioning for ionizable compounds, such as halogenated phenols, is questioned in view of the present results. Two thermodynamic Kow prediction models based on molecular properties are discussed in the context of the octanol-water partitioning of ionized and neutral compounds. The partition coefficients predicted by the molar volume based model (Gobas, et al. 1988) correlates with the experimental Kow results of this study better than Kow results predicted from the molecular surface area based model (Smejtek, et al. 1996). Results of this study support the hypothesis that partitioning of xenobiotics in the octanol-water system is fundamentally different than partitioning in lipid membrane-water systems.

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Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: Fenton-like reagent; MTBE; hydroxyl radicals; Fenton's reagent; humic acids; bicarbonate and carbonate; UV/H₂O₂; advanced oxidation processes; kinetic modeling; Pd membrane; phenol; benzene; partial oxidation. Includes bibliographical references (p. 446-454).

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xvii, 274 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: J. Schwartzbaum, School of Public Health. Includes bibliographical references (p. 171-203).

published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy