Interactions of ferrocenoyl-peptides in solution and on surfaces

The Ferrocenoyl-peptide-cystamines, such as [Fc-Gly-CSA](2) (Gly = glycine, CSA = cystamine), [Fc-Ala-CSA](2) (Ala = alanine) and Fc-conjugates involving collagen models, such as [Fc-(Pro(2)Gly)(n)-CSA](2) (Pro = proline, n = 1-6) are readily prepared by solution methods. In solution and the solid state, these systems exhibit intermolecular hydrogen bonding between adjacent peptide chains. For [Fc-Gly-CSA](2) this results in the formation of a supramolecular helicate with two different H-bonding patterns. Ferrocenoyl-collagen-cystamines form assemblies in solution, which melt at elevated tempertures. All systems for monolayers on gold surfaces, which show a well-behaved ferrocene-based electrochemistry, which allows the determination of the spatial requirements of the peptides on the surface.