Electron spin resonance studies of ion association. Part 7.—Effects of slow intramolecular cation exchange on the ENDOR of potassium-2,5-di-t-butyl p-benzoquinone

Slow intramolecular cation exchange can manifest itself in ENDOR by reducing the relative intensity of the response from hyperfine lines whose breadths are sensitive to the exchange process, even when the rate is too slow to contribute sensibly to the e.s.r. line breadths. The effect has been studied in potassium-2,5-di-t-butyl p-benzoquinone ion-pairs, and is satisfactorily understood using accepted theories of spin relaxation and solution ENDOR.