Raman scattering of α‐toluenethiol adsorbed on silver sol

Surface‐enhanced Raman scattering (SERS) of α‐toluenethiol adsorbed on a silver surface has been investigated. The controversial vibrational assignment of the molecule was refined by comparing the SERS spectra with the ordinary Raman spectra of α‐toluenethiol, α‐toluenethiolate, benzyl chloride and their deuterated species. Based on the assignment and the SERS selection rule, it is proposed that α‐toluenethiol is adsorbed as a thiolate on silver via its sulphur atom with both the methylene group and benzene ring oriented approximately parallel to the metal surface.