Oxidation–reduction Polymers: Iii. Standard Oxidation Potentials of 2,5-Dihydroxydiphenyl Sulphones

Abstract

The preparation of two new sulphonyl derivatives of methoxy-and naphtha-hydroquinone a s possible intermediate compounds in the synthesis of redox monomers is described. The standard oxidation potentials of these and other sulphonyl derivatives of hydroquinones were determined and compared with the values for similar compounds, reported previously (1).In Part I1 (I) we have described the preparation of redox polymers containing repeating hydroquinone units joined through a sulphone bridge to a polystyrene chain.Although 2,s-dihydroxydiphenyl sulphones were first synthesized by Hinsberg (2, 3) in 1894-1895, and in some cases their oxidized forins prepared, no systematic study of redox potentials of these and similar derivatives of hydro-and naphthahydro-quinones has been made. The sulphones whose redox potentials have been reported are p-toluenesulphonyl, p-bromobenzenesulphonyl, and d-camphor-10-sulphonyl derivatives of 1,4-naphthahydroquinone (4, 5) and the d-camphor-10-sulphonyl derivative of 2,s-dimethylhydroquinone (4). The redox potentials of these compounds are 121, 125, 114, and 135 mv, respectively, higher than the potentials of the corresponding parent quinones.Data previously obtained from potentiometric titrations (I) on intermediate and model cornpounds of redox polymers of the sulphone type showed the effect of various substituent 'Taken i n part from the thesis submitted by H. P . Kasserva