Three-Dimensional Pyrene-Fused N-Heteroacenes

Area of Science:

• Organic Chemistry
• Materials Science
• Supramolecular Chemistry

Background:

• Two-dimensional (2D) N-heteroacenes often suffer from poor solubility, limiting their processability and applications.
• Pyrene-fused systems are of interest due to their unique photophysical and electronic properties.
• Developing scalable synthetic routes for extended π-conjugated systems is crucial for materials innovation.

Purpose of the Study:

• To design and synthesize novel three-dimensional (3D) pyrene-fused N-heteroacenes.
• To investigate the effect of 3D covalent linkage on the solubility and properties of pyrene-fused N-heteroacenes.
• To establish a general strategy for the synthesis of large 3D pyrene-fused N-heteroacenes.

Main Methods:

• Iterative synthesis involving reduction of thiadiazole units to diamines and subsequent condensation with diketones.
• Characterization using Nuclear Magnetic Resonance (NMR) spectroscopy (1H, 13C, 2D), Mass Spectrometry (MS), UV-visible (UV-vis) absorption, Photoluminescence (PL), and Cyclic Voltammetry (CV).
• Structural analysis to determine molecular diameters.

Main Results:

• Four 3D pyrene-fused N-heteroacenes (P1-P4) with increasing lengths were successfully synthesized.
• The 3D covalent linkage significantly improved solubility compared to their 2D counterparts.
• The synthesized molecules exhibited diameters ranging from 3.66 to 10.88 nm.

Conclusions:

• The developed synthetic strategy provides a viable method for constructing large 3D pyrene-fused N-heteroacenes.
• These novel 3D materials demonstrate improved solubility, opening avenues for their use in various applications.
• The iterative approach allows for controlled extension of molecular size and properties.