Selective oxidants for organometallic compounds containing a stabilising anion of highly reactive cations: (3,5(CF 3) 2C 6H 3) 4B −)Cp 2Fe + and (3,5(CF 3) 2C 6H 3) 4B −)Cp* 2Fe +

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.