Abstract

A major interest in ferrocenium compounds arises from their usefulness as selective oxidants to prepare mixed-valence metallocenic stable compounds. In this paper, Cp 2FeBAr? 4=((3,5(CF 3) 2C 6H 3) 4B -)Cp 2Fe +) (a), and Cp* 2FeBAr? 4=((3,5(CF 3) 2C 6H 3) 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*Co II(C 8H 6)Fe II(C 8H 7)] with stoichiometric quantities of Cp 2FeBAr? 4 or Cp* 2FeBAr? 4 where [Cp*Co III(C 8H 6)Fe II(C 8H 7)]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.