We designed anthracene bisimide (ABI) derivatives having two triphenylamine (TPA) groups as donor units at the 9,10-positions to form a novel π-conjugated donor-acceptor system. These compounds and their analogues with ethynylene linkers were synthesized by Suzuki-Miyaura and Sonogashira coupling reactions, respectively. In UV-vis spectra, the linker-free derivatives showed broad absorption bands arising from intramolecular charge-transfer interactions. Introducing ethynylene linkers resulted in a considerable red shift of the absorption bands. In fluorescence spectra, the ethynylene derivatives showed intense emission bands at 600-650 nm. Their photophysical and electrochemical properties were compared with those of the corresponding mono TPA derivatives on the basis of theoretical calculations and cyclic voltammetry to evaluate the intramolecular electronic interactions between the donor and acceptor units.

Fused donor–acceptor triads composed of two tetrathiafulvalenes (TTFs) and benzoquinone (BQ; 1) or naphthoquinone (NQ; 2) were successfully synthesized. X‐ray structure analysis of the bis(n‐butylthio) derivative revealed that the molecules are stacked in a head‐to‐tail manner. The bis(n‐hexylthio)‐1 exhibited six‐pairs of one‐electron transfer waves in the cyclic voltammogram, corresponding to the formation of both reduction and oxidation states from −2 to +4. The unsubstituted and bis(methylthio) derivatives of 1 and 2 were active materials in positive electrodes for rechargeable batteries, several of which displayed energy densities exceeding 800 mWh g−1. The bis(methylthio)‐2 also functions as a positive electrode material for a rechargeable sodium‐ion battery.

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Tris‐fused π‐electron donors composed of two tetrathiafulvalenes (TTFs) and one extended TTF with anthraquinoid spacer (3) were successfully synthesized. The cyclic voltammograms of the tetrakis(n‐hexylthio)‐ and bis(ethylenedioxy) derivatives 3c and 3d consisted of three‐pairs of two‐electron redox waves. Spectroelectrochemitry of 3c indicated that two positive charges in 3c2+ are located mainly on the central extended TTF moiety. Coin‐type cells composed of the positive electrodes incorporating the unsubstituted‐3 (3a) and 3d showed the discharge capacities of 192 and 160 mAh g–1, respectively, in which six electrons per molecule are involved.

New π-conjugated 1,2-bis(2-aryl-1H-indol-3-yl)ethynes 1a-j having various substituents on the two aryl groups were efficiently synthesized via unusual 5-exo-digonal double isocyanide-acetylene cyclization reactions of 1,4-bis(2-isocyanophenyl)buta-1,3-diyne 3 and aryl Grignard reagents (R-MgBr, R = CH (1a), 4-HCCH (1b), 2-HCCH (1c), 3-MeOCH (1d), 3-(CH)NCH (1e), 4-FCCH (1f), 4-FCH (1g), 3-FCH (1h), 4-PhOCH (1i), and 2-Naph (1j)) in 19-85% yields. The UV-vis spectra were rationalized in detail using time-dependent DFT and single point calculations. The fluorescence emission peaks for 1a-j were observed at around 450 nm. Especially for 1f and 1j, those spectra displayed broad emission bands and relatively large Stokes shifts (3977-4503 cm), indicating the contribution of an intramolecular charge transfer. The absolute quantum yields (0.50-0.62) of 1a-j were higher than those of parent 8 (0.19) and 2-phenyl-1H-indole (0.11). The electrochemical features for 1a-j were investigated by cyclic voltammetry. The frontier molecular orbital levels for 1a-j were estimated based on the combination of oxidation potentials, UV-vis, and DFT calculated data. The structural property of 1,2-bis(2-phenyl-1H-indol-3-yl)ethyne 1a was characterized by several spectroscopic methods and finally determined by X-ray analysis of a single crystal of 1a recrystallized from ethyl acetate. The structural features of 1a-j were also supported by DFT calculations.