Supramolecular polymerization and bulk properties relationship in ester-functionalized N-annulated perylenediimides

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Organic Electronics

Background:

• N-annulated perylenediimides (NPDIs) are versatile organic semiconductors.
• Controlling self-assembly is crucial for tuning material properties.
• Side chain engineering significantly impacts molecular organization.

Purpose of the Study:

• To synthesize NPDIs with varying alkyl spacer lengths.
• To investigate the influence of side chain architecture on self-assembly in solution and solid states.
• To understand the structure-property relationships in functionalized NPDIs.

Main Methods:

• Synthesis of four N-annulated perylenediimide derivatives (1-4).
• Solution studies using spectroscopic methods to analyze supramolecular organization.
• Solid-state characterization through bulk assays to observe self-assembly behavior.

Main Results:

• Solution studies revealed a transition from H-type to J-type aggregation based on spacer length and carbonyl group influence.
• Bulk assays demonstrated an odd-even effect related to alkyl spacer length.
• Odd-spaced NPDIs (2, 4) formed disordered columnar hexagonal structures.
• Even-spaced NPDIs (1, 3) exhibited multiple crystalline and liquid crystalline phases.

Conclusions:

• Side chain functionalization is critical for designing NPDIs with tailored self-assembly.
• The carbonyl group and alkyl spacer length dictate supramolecular organization in solution.
• An odd-even effect in solid-state packing is observed, influenced by spacer length.