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A series of model oligomers consisting of combinations of a traditional strong donor unit (3,4-ethylenedioxythiophene), a traditional strong acceptor unit (benzo[ c ][1,2,5]thiadiazole), and the ambipolar unit thieno[3,4- b ]pyrazine were synthesized via cross-coupling methods. The prepared oligomers include all six possible dimeric combinations in order to characterize the extent and nature of donor–acceptor effects commonly used in the design of conjugated materials, with particular focus on understanding how the inclusion of ambipolar units influences donor–acceptor frameworks. The full oligomeric series was thoroughly investigated via photophysical and electrochemical studies, in parallel with density functional theory (DFT) calculations, in order to correlate the nature and extent of donor–acceptor effects on both frontier orbital energies and the desired narrowing of the HOMO–LUMO energy gap. The corresponding relationships revealed should then provide a deeper understanding of donor–acceptor interactions and their application to conjugated materials. 

Advances in the synthesis of low bandgap (Eg < 1.5 eV) conjugated polymers has produced organic materials capable of absorbing near-infrared (NIR) light (800—2500 nm), with these materials first applied to photodiode NIR detectors in 2007 as an alternative to more traditional inorganic devices. Although the development of organic NIR photodetectors has continued to advance, their ability to effectively detect wavelengths in the low-energy portion of the NIR spectrum is still limited. Efforts to date concerning the production of photodiode-based devices capable of detecting light beyond 1000 nm are reviewed.