Selenophene-Based Heteroacenes: Synthesis, Structures, and Physicochemical Behaviors

Area of Science:

• Organic Chemistry
• Materials Science
• Supramolecular Chemistry

Background:

• Heteroacenes are organic semiconductors with tunable electronic properties.
• Sulfur and selenium heteroatoms influence molecular packing and electronic characteristics.
• Developing novel fused-ring systems is crucial for advanced organic electronics.

Purpose of the Study:

• To design and synthesize novel thiophene- and selenophene-based heteroacenes.
• To investigate the impact of heteroatom substitution (sulfur vs. selenium) on molecular and electronic properties.
• To explore structure-property relationships in extended pi-conjugated systems.

Main Methods:

• Synthesis of new building blocks: dithienoselenophene (tt-DTS), diselenothiophene (tt-DST), and diselenoselenophene (tt-DSS).
• Preparation of thiophene- and selenophene-based heteroacenes with up to seven fused rings.
• Single-crystal X-ray diffraction analysis to confirm molecular structures.
• Spectroscopic characterization (UV-Vis, fluorescence) and cyclic voltammetry to study electronic properties.

Main Results:

• Successful synthesis of six novel heteroacenes, including systems with up to seven fused rings.
• Structural elucidation of key compounds (1, 2, 3a, 3c) via single-crystal analysis.
• Demonstrated modulation of molecular structure, spectroscopic features, and electrochemical behavior by varying heteroatoms (S/Se) and the number of selenophene units.
• Clear trends observed in properties correlating with structural modifications.

Conclusions:

• The study successfully developed new selenophene-containing heteroacenes with tunable properties.
• Heteroatom choice (sulfur vs. selenium) significantly impacts the electronic and structural characteristics of these fused systems.
• These findings provide valuable insights for designing next-generation organic electronic materials.