Electric Field-induced Charge Transfer of (Bu₄N)₂[Ru(dcbpyH)₂-(NCS)₂]
on Gold, Silver, and Copper Electrode Surfaces
Investigated by Means of Surface-enhanced Raman Scattering

摘要

The potential-induced charge transfer of the dye (Bu₄N)₂[Ru(dcbpyH)₂-(NCS)₂] (N719) on Au, Ag, and Cu electrode surfaces has been examined by surface-enhanced Raman scattering (SERS) in the applied voltage range between 0.0 and ?0.8 V. N719 is assumed to have a relatively perpendicular geometry with its bipyridine ring on the metal surfaces. A strong appearance of the carboxylate band at ~1370 cm^-1 indicates that the carboxyl group will likely be deprotonated on the metal surfaces. As the electric potential is shifted from ?0.8 to 0.0 V, the ロ (NCS) band at ~2100 cm^-1 on the electrode surfaces appears to undergo a shift in frequency and intensity change. This indicated that the charge transfer between the dye and metal electrode surfaces had occurred. Electric-field-dependent charge transfer differs somewhat depending on the type of metal surfaces as suggested from the dissimilar frequency positions of the ロ (NCS) band.