Conversion of the diamagnetic salt of the nonamethylferrocenylcarbenium primary cation into the paramagneticsalt of bis(nonamethylferroceniumyl)ethane has been studied by high-resolution NMR in solution and, mainly, by spin—lattice and spin—spin relaxation in solids. For the first time the dependence of the conversion rate on the nature of the anions BF4−, PF6−, AlBr4− and the aggregate state of the