Spectroscopic and spectroelectrochemical characterization of acceptor--sigma spacer--donor monolayers.

A novel self-assembled monolayer based on benzoquinone--sigma spacer--ferrocene assembly has been prepared on the surface of gold. The preceding paper gives the reaction conditions for the synthesis of the monolayer and a detailed electrochemical characterization of the assembly. In the present paper, the monolayer structure and the orientation of the redox moieties are followed by a detailed spectroscopic analysis. The monolayer has been characterized by reflectance absorbance IR spectroscopy, FT-Raman spectroscopy, and X-ray photoelectron spectroscopy at every step of modification. Additionally, spectroelectrochemical studies have been carried out by coupling Raman spectroscopy with cyclic voltammetry to elucidate the structural variations associated with the monolayer as a function of applied dc bias.