Tuning Solid-State Photoluminescence Frequencies and Efficiencies of Oligomers Containing One Central Thiophene-<i>S</i>,<i>S</i>-dioxide Unit

We have synthesized thienylene- and phenylene-based oligomers displaying solid-state photoluminescence efficiencies up to 70% and photoluminescence frequencies which cover the entire visible range. All compounds contain one central nonaromatic thienyl-1,1-dioxide moiety in the main chain. The tuning of the light-emission frequency was achieved by progressively varying the degree of π−π electron delocalization between the nonaromatic moiety and the α-linked aromatic rings. All compounds displayed greater electron affinities than thienylene or phenylene oligomers of comparable lengths, as deduced from the reduction potentials measured by cyclic voltammetry.