The characterization of complex phenols may be aided by comparing the n.m.r. spectrum of the phenol with that of its anion. The chemical shifts of the aromatic protons of the anion in deuterium oxide solution occur at higher field than those of the phenol in deuteriochloroform by characteristic amounts. Phenols bearing only alkyl or alkoxyl substituents show the following upfield changes: ortho, 0.16-0.28 p.p.m.; meta, 0.05-0.11 p.p.m.; para, 0.32-0.39 p.p.m. Comparison in dimethyl sulfoxide solution leads to these ranges: ortho, 0.42-0.59; meta, 0.19-0.38; para, 0.71-0.79 p.p.m. Phenols bearing other substituents may be characterized by study of appropriate models. Conversion to the acetate produces less explicit downfield changes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.