Abstract
A radical anion -NO(2) (.-) is formed upon an electrochemically reversible one-electron reduction of the square-planar Ni(II) complex of N-nitrobenzylcyclam. The -NO(2) (.-) group goes to occupy an axial position of the metal ion, thus establishing a significant electronic interaction with the metal center. In particular, the ESR spectrum supports the occurrence of an electron transfer from -NO(2) (.-) to the metal, which therefore presents a significant Ni(I) character. On re-oxidation, the nitrobenzyl side chain detaches and the Ni(II) complex is restored, providing an example of a fully reversible redox driven intramolecular motion.