Orientation of thiophenol adsorbed on silver determined by nonlinear vibrational spectroscopy of the carbon skeleton

The orientation of thiophenol adsorbed on silver is determined by comparing ab initio calculated and experimental sum-frequency generation (SFG) spectra measured between 9 and 20 mum using a tandem KTP/CdSe optical parametric oscillator. The molecule S-C bond is tilted similar to37degrees from the surface normal with the aromatic ring plane perpendicular to the surface.