A new redox site as an alternative to ferrocene to study electron transfer in self-assembled monolayers

Abstract

The cyclometallated ruthenium complex [Ru(bpy)₂(pp)]⁺ (bpy: 2,2′-bipyridine; pp: 2-(2′-ylphenyl)pyridine) was easily grafted to a ω-alkanethiol and the resulting compound was coadsorbed with 11-hydroxyundecanethiol on gold yielding a Self-Assembled Monolayer (SAM) in an analogous manner as for a ferrocene derivative, as shown by impedance spectroscopy; the kinetics of the heterogeneous electron transfer were shown to be very fast, compared to ferrocene, which makes this new redox site a promising candidate for further studies about molecular wires.