N N N

Transition-metal sandwich complexes are a unique organometallic family that withstands robust redox changes.1 This property can in several cases be used for electron-reservoir systems by adequate choice of the redox potentials. An illustration was provided by the 19-electron FeI complexes [FeI(η5-C5H4R)(η6-C6Me6)], R = H or various functional groups, the most electron-rich neutral molecules known based on their ionization potentials. These systems provide a range of stoichiometric and catalytic electron-transfer reactions for the activation of a large variety of substrates.2. This property can now be extended to dendrimers (via the covalent link R)3 whereby a defined number of electrons are involved in redox changes (e.g. C60 in Figure 1). Characterization of these materials and potential applications in molecular electronics will be discussed in the lecture.4 Figure 1. Transfer of 64 electrons from the dendritic 64-FeI complex to 64 C60 molecules giving dendri-64FeII, 64 C60.- characterized by Mössbauer spectroscopy (FeII) and the EPR spectrum of C60.- (right).