Abstract

A major interest in ferrocenium compounds arises from their usefulness as selective oxidants to prepare mixed-valence metallocenic stable compounds. In this paper, Cp2FeBAr?4=((3,5(CF3)2C 6H3)4B-)Cp2Fe +) (a), and Cp*2FeBAr?4=((3,5(CF3) 2C6H3)4B-) Cp*2Fe+) (b) are reported. These compounds have wide applications in the obtention of new organometallic salts with improved stability. The selective oxidation capacity of compounds a and b was investigated by the reaction of [Cp*CoII(C8H6)FeII(C 8H7)] with stoichiometric quantities of Cp2FeBAr?4 or Cp*2FeBAr?4 where [Cp*CoIII(C8H6)FeII(C 8H7)]BAr?4 was exclusively obtained. All salts that have BAr?4- as counterion showed an enhanced solubility in low-polarity solvents, especially in diethyl ether. This fact allowed us to perform non-conventional measurements like cyclic voltammetry in diethyl ether as solvent with NaBAr?4 as supporting electrolyte. Single-crystal structural determination of a and b was also achieved. © 2000 Elsevier Science S.A.