Direct (hetero)arylation polymerization, electrochemical and optical properties of regioregular 3-substituted polythiophenes with alkylsulphanyl and alkylsulfonyl groups

•3-substituted polythiophenes with alkylsulphanyl and alkylsulfonyl groups were prepared by direct(hetero)arylation polycondensation.•Direct arylation approach was used to attain high head-to-tail coupled regioregularity of the polythiophenes.•We lowered HOMO and LUMO energy levels of π-conjugated polymer by introducing alkylsulphanyl and alkylsulfonyl side chain into the polymer.