Stability of quinone and reduced forms in hydrogen fluoride and hydrogen fluoride–antimony pentafluoride superacid systems: an electrochemical and proton nuclear magnetic resonance study

Abstract

The techniques, electrochemistry and ¹H n.m.r., are shown to be complementary in the study of the stability limits of benzoquinone, semiquinone, and hydroquinone and their conjugated acids at various protonation stages in the HF derived superacid system. Acidity constants are determined and conditions for the disproportionation of the semiquinone form are established. The complete potential–pH diagram in HF could be defined.