Surface‐enhanced Raman spectroscopy of imidazole adsorbed on electrode and colloidal surfaces of Cu, Ag, and Au

Abstract

Abstract Surface‐enhanced Raman spectra have been obtained from imidazole adsorbed on Cu and Ag electrodes, and on Cu, Ag, and Au colloids at pH ranging from 5.6 to 11.0. For these pHs, the imidazole molecule is coordinated through its unshared electron pair on its ‘pyridine’ nitrogen to the metal surfaces. On the Cu and Au colloidal systems, the imidazole molecule adsorbs with the ring perpendicular to the metal surface since only in‐plane vibrations are observed. On the other hand, both the in‐plane and out‐of‐plane vibrations are observed on the Cu and Ag electrodes, and on the Ag colloid, therefore the adsorbed imidazole is tilted at an angle with respect to the surface normal. Copyright © 2006 John Wiley & Sons, Ltd.