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New symmetrical arylene bisimide derivatives formed by using electron-donating–electron-accepting systems were synthesized. They consist of a phthalic diimide or naphthalenediimide core and imine linkages and are end-capped with thiophene, bithiophene, and (ethylenedioxy)thiophene units. Moreover, polymers were obtained from a new diamine, N,N′-bis(5-aminonaphthalenyl)naphthalene-1,4,5,8-dicarboximide and 2,5-thiophenedicarboxaldehyde or 2,2′-bithiophene-5,5′-dicarboxaldehyde. The prepared azomethine diimides exhibited glass-forming properties. The obtained compounds emitted blue light with the emission maximum at 470 nm. The value of the absorption coefficient was determined as a function of the photon energy using spectroscopic ellipsometry. All compounds are electrochemically active and undergo reversible electrochemical reduction and irreversible oxidation processes as was found in cyclic voltammetry and differential pulse voltammetry (DPV) studies. They exhibited a low electrochemically (DPV) calculated energy band gap (Eg) from 1.14 to 1.70 eV. The highest occupied molecular orbital and lowest unoccupied molecular orbital levels and Eg were additionally calculated theoretically by density functional theory at the B3LYP/6-31G(d,p) level. The photovoltaic properties of two model compounds as the active layer in organic solar cells in the configuration indium tin oxide/poly(3,4-(ethylenedioxy)thiophene):poly(styrenesulfonate)/active layer/Al under an illumination of 1.3 mW/cm2 were studied. The device comprising poly(3-hexylthiophene) with the compound end-capped with bithiophene rings showed the highest value of Voc (above 1 V). The conversion efficiency of the fabricated solar cell was in the range of 0.69–0.90%.

Because polymeric materials have recently found widespread use in light-emitting devices, we decided to exploit a novel group of copolymers as active materials in such devices and managed to obtain polymeric electroluminescent diodes emitting blue light. The electroluminescent devices were fabricated using the copolymers composed of 2-(carbazol-9-yl)ethyl methacrylate (CEM) and 3-phenyl-7-methacryloyloxyethoxy-1-methyl-1H-pyrazolo[3,4-b]-quinoline (MEPQ). The concentration of MEPQ in the copolymers was kept at a low level and changed from 0.5, 1, 2, 5 to 8 mol %. The turn-on voltage for light emission was 8 V. It was found that the emission peaks of the electroluminescent devices were blue-shifted by ≈9 nm in comparison to photoluminescence spectra of the copolymers in thin film. Moreover, as the concentration of MEPQ in the copolymers was increased from 0.5 to 8 mol %, the photoluminescence emission peaks shifted slightly to the red from 447 to 455 nm, while the electroluminescence emission peaks moved from 438 to 447 nm. Because MEPQ groups are bound to the polymer backbone, light emission was equally spread on the whole surface.

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