Intramolecular Noncovalent Interaction-Driven Syn-/Anti-Conformational Regulation in Nonfused-Ring Electron Acceptors

Area of Science:

• Organic electronics
• Materials science
• Supramolecular chemistry

Background:

• Molecular conformation is crucial for organic material properties.
• Precise control over conformation in non-fused-ring electron acceptors (NFREAs) is challenging.
• Modulating syn- and anti-conformation preferences is key for optimizing NFREAs.

Purpose of the Study:

• To demonstrate precise engineering of NFREAs through conformation-directed design.
• To investigate the influence of syn-/anti-conformational preferences on molecular and device properties.
• To provide guidelines for developing high-performance organic solar cells.

Main Methods:

• Utilizing intramolecular noncovalent S···F interactions to achieve syn-to-anti-conformational transition in NFREAs.
• Systematic investigation of how conformational preferences affect planarity, rigidity, self-assembly, and charge transport.
• Fabrication and characterization of organic solar cells using syn- and anti-conformed NFREAs.

Main Results:

• The anti-conformation of TT-F (anti-TT-F) exhibited enhanced crystallinity, reduced reorganization energy, and improved charge carrier mobility compared to the syn-conformation.
• Binary and ternary organic solar cells based on anti-TT-F achieved high power conversion efficiencies of 15.08% and 19.88%, respectively.
• Conformational regulation significantly impacts molecular planarity, rigidity, and self-assembly.

Conclusions:

• Intramolecular noncovalent S···F interactions provide a powerful strategy for controlling NFREA conformation.
• The anti-conformation is superior for charge transport and device performance in these NFREAs.
• Conformational engineering offers a new dimension for designing high-performance organic electronic materials and devices.