Lawrence Berkeley National Laboratory

A series of pyrene-fused azaacene-type conjugated molecules containing two pyrazine units and up to eight rectilinearly arranged aromatic rings were prepared by condensation coupling reactions in moderate yields. The geometries and electronic structures associated with 2 and 5 were evaluated by DFT calculations. Photophysical properties indicated that these systems possess delocalized structures, and their optoelectronic properties can be tuned by extending the π-conjugated length and introducing electronic-withdrawing groups. The compounds were thoroughly investigated by XRD studies, electrochemistry and DFT calculations. High thermal stability and tunable energy levels make them excellent candidates as a class of organic molecular materials.