Synthesis, crystal structures, electrochemical and protein-binding properties of ferrocene–indole conjugates

Abstract

This paper describes the synthesis, characterisation and electrochemical properties of three redox-active ferrocene–indole compounds, N-(ferrocenylmethylenyl)tryptamine (Fc–CHNC₂H₄-indole) (Fc1), N-(ferrocenylmethyl)tryptamine (Fc–CH₂NHC₂H₄-indole) (Fc2) and indole-3-(N-(6-(N-ferrocenylmethyl)aminohexyl))carboxamide (Fc–CH₂NHC₆H₁₂NHCO-indole) (Fc3). The X-ray crystal structures of Fc1 and Fc2 have been investigated. The recognition of the redox-active ferrocene–indole compounds Fc2 and Fc3 by indole-binding proteins including bovine serum albumin and tryptophanase has been studied by electrochemical and luminescence titrations and enzyme inhibition assays.