Electron Transfer Reactions between Gels and Quinones

Electron transfer reactions of quinone derivatives (QDs) with poly(4-vinylpyridine) gels in organic solvents were studied by means of ESR spectroscopy. Formation of radical anions from the QDs and cations from polymeric base was established. The QD2- anions resulting from disproportionation of the QD•- radical anions produce additional cross-links in the gel, causing it to collapse. Sulfhydryl compounds complexed with the gel prevent formation of the ESR signals when the QDs are supplied into the solvent surrounding the gel under oxygen-free conditions. Oxidation of the sulfhydryl compound adsorbed onto the gel results in its desorption, enabling the gel to react with the QD, producing ESR signals. Gels modified with the sulfhydryl compounds collapse in response to the supply of oxygen into their liquid environment.