ELECTRON-SPIN-RESONANCE SPECTRA OF THE PERRUTHENATE(VII) ION, [RUO4]-

Electron spin resonance spectra of the [RuO4]- ion {as A[RuO4], where A = NPr(n)4, N(PPh3)2 or PPh4} in frozen glasses of dichloromethane at ca. 90 K have been recorded; for A = NPr(n)4, g(x) = 1.93, g(y) = 1.98 and g(z) = 2.06. The spectrum of [RuO4]- (and its electronic spectrum) have been interpreted and compared with those of an alkaline aqueous solution containing ruthenium(VII) species. The ESR spectrum of powdered potassium ruthenate(VI), trans-K2[RuO3(OH)2], at ca. 90 K was also recorded, and the preparation of [PPh4][RuO4], a new salt of [RuO4]-, is described.