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Oxygen- and sulfur-containing positively charged polycyclic aromatic hydrocarbons
Dongqing Wu1, Wojciech Pisula, Monika C Haberecht
1Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128, Mainz, Germany.
Organic Letters
|November 19, 2009
Summary
Researchers synthesized novel benzo[5,6]naphthaceno[1,12,11,10-jklmna]xanthylium (BNAX) and benzo[5,6]naphthaceno[1,12,11,10-jklmna]thioxanthylium (BNATX) salts. These compounds exhibit unique optoelectronic properties and self-assemble into ordered liquid crystalline phases.
Area of Science:
- Organic Chemistry
- Materials Science
- Supramolecular Chemistry
Background:
- Polycyclic aromatic hydrocarbons (PAHs) are crucial in developing advanced materials.
- Understanding how heteroatom incorporation affects PAH properties is key for material design.
- Benzo[5,6]naphthaceno[1,12,11,10-jklmna]xanthylium (BNAX) and benzo[5,6]naphthaceno[1,12,11,10-jklmna]thioxanthylium (BNATX) represent novel PAH structures.
Purpose of the Study:
- To synthesize novel BNAX and BNATX salts.
- To investigate the impact of heteroatom variation on the optoelectronic properties of PAHs.
- To explore the self-assembly behavior and liquid crystalline properties of BNAX derivatives.
Main Methods:
- Synthesis of BNAX and BNATX salts.
- UV-vis absorption and emission spectroscopy for optoelectronic characterization.
- X-ray scattering and molecular modeling to study self-assembly.
Main Results:
- Successful synthesis of BNAX and BNATX salts.
- Significant differences in UV-vis absorption and emission spectra due to heteroatom incorporation.
- Observation of ordered columnar liquid crystalline phases in di- and tridodecyl-substituted BNAX salts.
- X-ray scattering and modeling revealed self-assembly of three BNAX molecules into disklike structures, forming hexagonal columnar phases.
Conclusions:
- Heteroatom variation in the same PAH core profoundly alters optoelectronic properties.
- BNAX derivatives demonstrate potential for forming ordered liquid crystalline phases.
- The self-assembly mechanism involves the formation of disklike molecular aggregates organized into hexagonal columnar structures.
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