SURFACE-ENHANCED RAMAN-SPECTROSCOPY OF CRYSTAL VIOLET IN THE PRESENCEOF HALIDE AND HALATE IONS WITH NEAR-INFRARED WAVELENGTH EXCITATION

The interaction of crystal violet (CV) with halide, halate ions, and p yridine and the interaction of CV with colloidal silver surface have b een studied by surface-enhanced Raman spectroscopy (SERS) with near-in frared (NIR) excitation, Cl-, Br, I, and BrO3 ions as well as pyridine give rise to a large enhancement of the Raman modes of CV, while no R aman bands of CV could be observed in the presence of ClO3- and IO3- i ons. The adsorbability of the complexes CV/BrO3- and CV/pyridine is hi gher than that of ClO3- and IO3- ions, while the latter is higher than that of the complexes CV/ClO3- and CVI103-. CV interacts with the sil ver surface quite possibly through the lone pair electrons on the N at oms, Halide and halate ions account nor only for part of the surface e nhancement from the surface plasmon excitation resonance but also for the chemical enhancement in the NIX-SERS, The chemical enhancement fac tors caused by Cl-, Br-, I-, and BrO3- ions are estimated to be about 49, 77, 15, and 36, respectively.