Surface-enhanced Raman scattering of aromatic sulfides in aqueous gold sol

A surface-enhanced Raman scattering (SERS) study has been performed for benzyl phenyl sulfide (BPS) and dibenzyl sulfide (DBS) in aqueous gold sol to examine the feasibility of the occurrence of surface-induced photoreactions of aromatic sulfides. Although BPS and DBS were reported to be decomposed into mercaptides on the silver surface by the 514.5 nm radiation, the molecules were found not to undergo such reactions on the gold surface. Such a difference in behavior was speculated to be associated with the different adsorption strength of BPS and DBS on gold and sliver. The absorption hands of BPS and DBS seemed to be substantially broadened on silver so that the low-energy tails of the broadened absorption bands were in resonance with the 514.5 nm radiation, while the electronic absorption hands were not broadened sufficiently on the gold surface to absorb risible radiation.