SURFACE-CONFINED MONOMERS ON ELECTRODE SURFACES .3. ELECTROCHEMICAL REACTIONS AND SCANNING PROBE MICROSCOPY INVESTIGATIONS OF OMEGA-(N-PYRROLYL) ALKANETHIOL SELF-ASSEMBLED MONOLAYERS ON GOLD

摘要

The formation and subsequent polymerization of omega-(N-pyrrolyl)alkanethiol monolayers on polycrystalline gold under various conditions was performed. Polymer formation in the monolayer is suppressed by addition of H2O or pyridine to the Bu(4)NClO(4)-CH3CN or Bu(4)NClO(4)-propylene carbonate (PC) electrolyte. Exposure of gold electrodes to ethanol solutions of n-hexanethiol and N-(6-mercaptohexyl)pyrrole results in monolayers which do not reflect the composition of the dosing solution. The presence of 75% n-hexanethiol in the assembly solution results in mixed monolayers which still display surface-confined pyrrole oxidation, but no voltammetric evidence for polymer formation. Scanning tunneling microscopy of the oxidized monolayers on Au(111)/mica yields images which are not substantially different from those of the unoxidized monolayers on Au(111)/mica. [References: 29]