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Updated: May 23, 2026
Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
Supramolecularly engineered perylene bisimide assemblies exhibiting thermal transition from columnar to multilamellar
Shiki Yagai1, Mari Usui, Tomohiro Seki
1Department of Applied Chemistry & Biochemistry, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan. yagai@faculty.chiba-u.jp
Functionalized perylene bisimide (PBI) forms hydrogen-bonded rosettes that self-assemble into columnar structures. Heating induces a transition to a lamellar phase, significantly enhancing photoconductivity due to charge transfer. This study reveals a novel structural transformation with optoelectronic implications.
Area of Science:
- Materials Science
- Supramolecular Chemistry
- Organic Electronics
Background:
- Perylene bisimide (PBI) derivatives are widely studied for their optoelectronic properties.
- Self-assembly of functionalized PBI into ordered structures is crucial for advanced materials.
- Controlling supramolecular organization impacts material performance.
Purpose of the Study:
- To functionalize PBI with ditopic cyanuric acid for controlled self-assembly.
- To investigate the formation of hydrogen-bonded supermacrocycles and columnar architectures.
- To study the structural transition and its effect on photoconductivity.
Main Methods:
- UV-vis and NMR spectroscopy for aggregation studies.
- Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM) for nanostructure visualization.
- X-ray diffraction (XRD) for structural analysis (hexagonal columnar and lamellar phases).
- Differential Scanning Calorimetry (DSC) and Infrared (IR) spectroscopy for thermal and bonding analysis.
- Flash-photolysis time-resolved microwave conductivity (FP-TRMC) and transient absorption spectroscopy for optoelectronic properties.
Main Results:
- Formation of hydrogen-bonded PBI rosettes and cylindrical fibrillar nanostructures.
- Self-assembly into hexagonal columnar (Col(h)) structures in solution and upon casting.
- A thermally induced structural transition from Col(h) to a highly ordered lamellar (Lam) structure.
- Rearrangement of hydrogen-bonding motifs from rosette to linear tape during the transition.
- Remarkable increase in transient photoconductivity in the Lam structure compared to the Col(h) structure due to efficient charge transfer.
Conclusions:
- Functionalized PBI can form ordered supramolecular architectures via hydrogen bonding and π-π stacking.
- A reversible structural transition between columnar and lamellar phases can be achieved through thermal treatment.
- The lamellar phase exhibits superior photoconductivity, attributed to enhanced charge carrier generation via intramolecular charge transfer.
