Charge Mapping in 3(10)-Helical Peptide Chains by Oxidation of the Terminal Ferrocenyl Group

Two series of 3(10)-helical peptides of different lengths and rigidity, based on the strongly foldameric ?-aminoisobutyric acid and containing a terminal ferrocenyl unit, have been synthesized. Oxidation-state sensitive spectroscopic tags of helical peptides, the N-H groups, allowed mapping of the charge delocalization triggered by oxidation of the terminal ferrocenyl moiety and were monitored by IR spectroelectrochemistry.