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Functionalizable polycyclic aromatics through oxidative cyclization of pendant thiophenes
John D Tovar1, Aimee Rose, Timothy M Swager
1Department of Chemistry, Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Journal of the American Chemical Society
|June 27, 2002
Summary
Researchers developed a method to synthesize large sulfur-containing polycyclic aromatics using iron(III) chloride. This strategy controls cyclization, preventing polymer formation and enabling further functionalization for studying polymer properties.
Area of Science:
- Organic Chemistry
- Polymer Science
- Materials Science
Background:
- Polycyclic aromatic hydrocarbons (PAHs) are crucial in materials science.
- Controlling polymerization of aromatic precursors remains a challenge.
- Thienyl-containing precursors offer unique reactivity for PAH synthesis.
Purpose of the Study:
- To develop a general strategy for synthesizing large sulfur-containing polycyclic aromatics.
- To investigate the influence of structural rigidity on polymer photophysical properties.
- To explore cyclization and polymerization pathways of thienyl-based polymers.
Main Methods:
- Iron(III) chloride mediated oxidative cyclization of thienyl precursors.
- Controlled cyclization of oxidized intermediates to suppress polymer formation.
- Halogenation and functionalization of synthesized aromatic cores.
- Synthesis and photophysical characterization of arylene-ethynylene polymers.
Main Results:
- A general strategy for large sulfur-containing PAH synthesis was established.
- Controlled cyclization pathways were achieved, minimizing polymer formation.
- Synthesized polymers exhibited tunable photophysical properties based on chromophore rigidity.
- Increased excited-state lifetimes were observed with rigid, aromatized chromophores.
Conclusions:
- Oxidative cyclization of thienyl precursors provides a versatile route to complex PAHs.
- Synthetic control over rigidity significantly impacts polymer photophysical behavior.
- This work offers insights into structure-property relationships in conjugated polymers.
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