Synthesis and Properties of Fused Polycyclic Donor-Acceptor Compounds Containing Carbazole and Diazapyrene Skeletons

Fused polycyclic aromatic compounds containing carbazole and diazapyrene skeletons as electron donors and acceptors, respectively, were synthesized in a few steps from readily accessible starting materials. The incorporation of diazapyrene units into the polycyclic compounds resulted in significant bathochromic shifts in their absorption and emission bands compared to those of the corresponding carbazole derivatives. Electrochemical measurements and density functional theory calculations were performed to gain further insight into their electronic properties. Our findings demonstrate that the incorporation of nitrogen atoms and substituents, as well as the different topologies of the fused-ring system, exert a profound effect on the electronic properties of the polycyclic compounds. A series of fused-ring compounds containing carbazole and diazapyrene moieties as donors and acceptors, respectively, was synthesized in a short and straightforward manner from readily available carbazole derivatives. The incorporation of substituents and alteration of the fused-ring topology significantly changed their optical and electrochemical properties. image