Solvated electrons and electron–cation aggregates in solutions of the alkali metals in 12-crown-4

Abstract

The alkali metals sodium, potassium, rubidium, and caesium dissolve in the cyclic ether 12-crown 4 (1,4,7,10-tetraoxacyclododecane) to give blue solutions containing metal cations, metal anions, electrons, and cation–electron pairs. The metal anions give rise to a characteristic optical absorption band; Na^– and Rb^– have also been detected by n.m.r. as ringlet resonances at high field. E.s.r. signals due to solvated electrons and electron–cation pairs are detected in frozen solutions; on melting the two resonances combine to give a single, time-averaged signal.