RELATIONSHIP BETWEEN RESONANT RAMAN-SCATTERING IN AG-C2H4 COMPLEXES AND SERS

Concentrations less than 10(-2) of silver dispersed in C2H4 matrices (ratio of Ag atoms and C2H4 molecules in the matrix) induce an absorption band in the visible range by electron transfer excitation and (with the exception of the C-H stretch vibrations) shifted Raman bands, assigned to resonant enhancement by two orders of magnitude by electron transfer in Ag-C2H4 complexes. Both phenomena are absent for Ag dispersed in C2H6. These results are analogous to the chemical specific and vibrational selective surface-enhanced Raman scattering (SERS) of C2H4 and C2H6. The loss of the electron transfer excitation by mixing oxygen into the Ag-C2H4 matrix (as measured by Ozin et al.) corresponds to the quenching of SERS by oxygen.