Electrochemistry of ruthenium metallocenes .1. Synthesis, NMR, and anodic electrochemical behavior of vinyl-substituted ruthenium cyclophane complexes

Ruthenium complexes of 4-ethenyl- and 4,12-diethenyl[2(2)]paracyclophane have been synthesized and investigated by NMR spectroscopy as well as electroanalytical techniques. The structure of [(C20H20)Ru(II)(C16H16)](BF4)(2) .(acetone) was determined by X-ray crystallography. Consistently, the results show that electron density is decreased in those (''disturbed'') vinyl groups bound directly to ruthenium-complexed cyclophane decks. Electrochemical oxidation of the complexes depends on the presence or absence of undisturbed vinyl groups and results in the formation of redox-active films on the electrode.