Ferrocenoyl-amino acids: redox response towards di- and trivalent metal ions

Abstract

The interaction of six ferrocene-amino acid conjugates (Fc–CO–Gly–OH ( 2a), Fc–CO–Asp–OH ( 3a), Fc–CO–Glu–OH ( 4a), 1,1′-Fc(CO–Gly–OH) ( 2b), 1,1′-Fc(CO–Asp–OH) ( 3b), and 1,1′-Fc(CO–Glu–OH) ( 4b)) with Mg 2+, Ca 2+, Zn 2+, La 3+, and Tb 3+ was investigated in aqueous solutions using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Addition of metal ions to solutions caused, in some cases, large changes in the half-wave potential, E 1/2. Our electrochemical results show that the Gly systems, 2a and 2b, show a preference for binding Mg 2+, whereas the Asp and Glu conjugates prefer binding Ln 3+.