Substituted phenols, hydrogen transfer between

Single-temperature equilibrium constant values may also yield quantitative information about reaction enthalpies, provided that the entropy term can be estimated. Take, for example, reaction 14.32, which involves hydrogen transfer between two substituted phenols (ArOH and Ar OH see examples in figure 14.4). Note that Kc = Km in this case. 

When two polymeric systems are mixed together in a solvent and are spin-coated onto a substrate, phase separation sometimes occurs, as described for the application of poly (2-methyl-1-pentene sulfone) as a dissolution inhibitor for a Novolak resin (4). There are two ways to improve the compatibility of polymer mixtures in addition to using a proper solvent modification of one or both components. The miscibility of poly(olefin sulfones) with Novolak resins is reported to be marginal. To improve miscibility, Fahrenholtz and Kwei prepared several alkyl-substituted phenol-formaldehyde Novolak resins (including 2-n-propylphenol, 2-r-butylphenol, 2-sec-butylphenol, and 2-phenylphenol). They discussed the compatibility in terms of increased specific interactions such as formation of hydrogen bonds between unlike polymers and decreased specific interactions by a bulky substituent, and also in terms of "polarity matches" (18). In these studies, 2-ethoxyethyl acetate was used as a solvent (4,18). Formation of charge transfer complexes between the Novolak resins and the poly (olefin sulfones) is also reported (6). 

Photodecomposition of some ortfeo-substituted aryldiazonium ions leads to unusual reaction products due to hydrogen atom transfer between the ortho-substituent and the radical center derived by loss of nitrogen from the diazonium ion. Thus, 2-diethylaminobenzenediazonium salts yield N-ethylaniline via the intermediate 3. Deuterium is not incorporated into the benzene ring from either DjO or CD3OD.2 Decomposition of the diazonium salt 4 leads to a benzocyclobutene as the principal product. The influence of the nitro substituent is important, because the un-nitrated diazonium salt is decomposed to give a phenol in the normal manner. ... 

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