Electron spin resonance studies of radicals and radical-ions in solution. Part III. Ion association in lithium naphthalide solutions
Electron spin resonance spectra of lithium naphthalide ion-pairs and of naphthalene mono-anions in a number of organic solvents have been examined. The hyperfine interaction of the lithium nucleus was determined for solutions of lithium naphthalide in 2-methyltetrahydrofuran and tetrahydropyran between –40 and +40°. From the variation of the lithium coupling constant with temperature, and from the differential broadening of the hyperfine components of the spectrum, we conclude that the likely configuration of the ion-pair involves an equilibrium between a simple ion-pair and an ion-pair–solvent complex.