A tri-nuclear iron (III) complex [Fe 3 (μ 3 -O)(O 2 CC 6 H 4 SCH 3 ) 6 (Py) 3 ]FeCl 4 has been synthesized and characterized by X-ray crystallography, Surface enhanced Raman Scattering (SERS), Fourier Transform Infra Red (FT-IR), Ultraviolet–Visible (UV–Vis) spectroscopy and Thermogravimetric analysis (TGA)/Differential scanning calorimetry (DSC). The functionalized thio-methyl groups around the periphery of the complex 1 may provide binding sites to the surface of some specific materials, such as noble metals. The Ag sols and complex 1-Ag sol had been characterized by SERS and UV–Vis spectroscopy. The complex 1 were also self-assembled on gold electrode by AuS bond, exhibiting an irreversible process at E 1/2 =0.967V (ΔE=0.525V). Meanwhile the Raman spectra were compared with FT-IR, and the results indicated that the strong Raman lines either correspond to weak Infrared absorptions or are absent in the Infrared spectra.