Adsorption on Chromium

4-Ferrocenylphenyl isocyanide (3) on a Cr electrode has been studied by cyclic voltammetry [66]. The Cr substrate was prepared by thermal evaporation of Cr onto glass microscope slides and stored under nitrogen. 

The isocyanide monolayer was formed by immersing the Cr slide in a 1 mM isocyanide solution under argon for 30 min. The redox wave, which is observed in cyclic voltammograms of the modified Cr electrode, proves that the 4-ferrocenyl-phenyl isocyanide is adsorbed on the metal surface. When a Cr electrode is exposed for 2 h to a solution of ferrocene, no redox wave was observed in the CV, which demonstrates that the isocyanide group is necessary for adsorption. No spectroscopic studies were performed on the adsorbed isocyanide. 

CNBu )3. Even though the isocyanides on the metal and in the complex are bonded to the same metal in the same zero oxidation state, their v(N=C) values differ by approximately 75cm . Thus, even in a case where the metal complex might be considered to be a quite good model for T -bonded isocyanide on Pt metal, the v(N=C) values are significantly different Of course, the environment around the Pt to which the isocyanide is bonded is very different in the complex and on the surface. 

On Au only the T) mode is observed on all Au forms (film, powder, nanoparticles) with both alkyl and aryl isocyanides. 

On Ag with the exception of a study of CH3NC at very low coverage on Ag(311), all isocyanides are T) bonded on aU forms of Ag. 

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Degenhardt, J., McQuillan, A.J. (1999) Mechanism of oxalate ion adsorption on chromium oxide-hydroxide from pH dependance and time evolution of ATR-IR spectra, Chem, Phys. Lett Vol. 31,179-184,0009-2614. 

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