Electron spin resonance studies of preferential solvation in solutions of potassium in amines and ethers

Abstract

Electron spin resonance spectra of solutions of potassium in tetrahydrofuran–ethylamine, tetrahydrofuran–diglyme, ethylamine–diglyme, and ethylamine–ethylenediamine mixtures are reported and compared with spectra obtained from the four pure solvents. Strong evidence for preferential solvation was observed in all mixtures, with the strength of solvation increasing in the order tetrahydrofuran < ethylamine < diglyme < ethylenediamine. Electron spin resonance spectra of mixtures containing ethylenediamine were used to investigate the nature of the single line spectrum obtained from solutions in ethylenediamine alone. It is concluded that this signal is an 'ammonia-like' time averaged spectrum arising from solvated electrons and ion-pairs.