Assessment of the Optical, Electrochemical, and Self‐Assembly Morphology of the Symmetric Perylene Diimide‐Bearing Apremilast Intermediate Amine

The robust nature of perylene diimide ( PDI ) toward thermal, optical, and redox properties makes it an ideal candidate for many applications including optoelectronic, chemo‐bio sensing, liquid crystal, and photo‐ catalysis. The current study aimed to design and synthesize a novel PDI scaffold bearing apremilast intermediate amine. The UV–visible (vis) absorption spectroscopy investigation revealed its characteristic three absorption peaks at 523, 488, and 456 nm. In contrast, fluorescence spectroscopy investigation illustrated two prominent emission peaks at 527 and 564 nm, and one small peak at 614 nm. The computed E LUMO and E HOMO values of −4.039 and −6.031 eV align well with the experimental values of −3.156 and −5.390 eV determined through electrochemical and optical measurements. The water‐dependent UV–vis absorption analysis revealed that the PDI (10 µM) showed a minor change in absorption intensity as the water percentage in THF increased from 10% to 60%. As the proportion of water grows from 70% to 90%, the absorption intensity decreases and shifts to the red. The PDI emission spectroscopy investigation revealed that increasing the water percentage from 20% to 90% gradually reduced the emission intensity and demonstrated an aggregation‐caused quenching (ACQ) effect. With increasing water percentage in THF, the PDI transformed from its monomer state to the J‐aggregates of crystalline fractured angular grain morphology, which exhibit intense yellow emission.