Following the reports of Werner and Salzer in 19721 on the synthesis of the tris(η75-cyclopentadienyl)dinickel cation, Cp3Ni2+, there has been considerable interest in so-called “triple-decker sandwich” compounds, partly due to the attractive possibility of building extended, electron-delocalized, organometallic chains.2,3 The oxidation-reduction properties of these molecules, as well as the physical properties of their radical ions, are of obvious interest in attempting to understand the nature of the metal-metal interaction in these compounds and the degree to which delocalization may occur. © 1979, American Chemical Society. All rights reserved.