A CdRu(bpy)(CN)4 surface derivative can be formed on SnO2 and Pt electrodes by soaking a cadmium-plated electrode in an aqueous solution of K2Ru(bpy)(CN)4. Diffuse reflectance FTIR confirms the formation of the surface species. Electrodes modified in this manner are found to be luminescent. The emission intensity and excited-state lifetime can be electrochemically modulated, since they are dependent on the ruthenium oxidation state. The derivatizing-layer lifetime can be fit to the Stern-Volmer equation, suggesting a bimolecular quenching process. The rate constant for this process is affected by the type of supporting electrolyte cation present. Forming a [CdFe(CN)6]2-/- surface derivative on a SnO2 electrode prior to derivatization with [CdRu(bpy)(CN)4]0/+, improves the heterogeneous charge-transfer rates. Variation in the alkali cation intercalated into the [CdFe(CN)4]2- layer prior to reaction with K2Ru(bpy)(CN)4 leads to major differences in overlayer structure, suggesting a relationship between derivative structure and charge-transfer dynamics.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry