Several oligothiophenes with 2-mesitylthio (MesS) substituents have been prepared and studied by UV-visible spectroscopy and cyclic voltammetry. These compounds can be considered as models for thiol-terminated conjugated oligomers, which have attracted intense interest as materials for molecular-scale electronics. Three types of oligomers were prepared: α, ω-bis (mesitylthio) oligothiophenes 4-7, α, ω-bis (mesitylthio) oligo (3, 4- ...