Beta-Functionalised alpha,alpha'-conjugated oligothiophenes with alkylsulfanyl groups: synthesis and characterisation

alpha-oligothiophenes are important materials for optical and electronic devices and are used as model compounds for the characterization of charge carriers in conjugated chains. The presence of beta-alkylsulfanyl groups on the thiophene ring reduces the band-gap between ground and excited state, and influence the electrical and optical properties in a positive manner in relation to possible applications of these materials. the syntheses of a homologous series of alkylsulfanyl oligothiophenes, up to octithiophenes, is discussed