The use of sulfinyl groups as thermally eliminable groups in precursor routes towards conjugated systems, like OC1C10-PPV, is evaluated by different techniques: Fourier Transform Infrared Spectroscopy (FT-IR), Ultraviolet Visible Spectroscopy (UV-Vis), X-ray Photoelectron Spectroscopy, Electron Spin Resonance (ESR) and Raman Spectroscopy. In-situ FT-IR and UV-Vis, allows determination of the temperature range where elimination takes place. XPS was performed on the surfaces of the polymer films.