The synthesis, spectroscopic, electrochemical and X-ray diffraction characterization of novel bridged ferrocene precursors for use in self-assembled monolayers

Abstract

The synthesis of 1,6-diferrocenylhexane-1,6-dione ( I), 1-ferrocenylcarbonyl-2-ferrocenylcyclopentene ( II) and 1,6-diferrocenylhexane ( III) is reported. All three compounds were characterized by 1H NMR, 13C NMR, and infra-red spectroscopy, mass spectrometry, cyclic voltammetry and chronoamperometry. Compounds I and III each exhibit a single two electron transfer, while compound ( II) exhibits two single electron transfers. Compounds ( I) and ( II) were further studied by single crystal X-ray diffraction. In compound ( I), both carbonyl groups are in plane with the adjacent ferrocenyl Cp ring. For compound ( II) one of the ferrocenyl Cp rings is coplanar with the carbonyl group, the other with the double bond of the cyclopentene ring, but the C O moiety and the double bond are basically perpendicular to each other.