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Updated: May 24, 2026
08:12
Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers
Published on: December 16, 2022
ortho-Phenylene oligomers with terminal push-pull substitution
Jian He1, Sanyo M Mathew, Sarah D Cornett
1Department of Chemistry & Biochemistry, Miami University, Oxford, OH 45056, USA.
Organic & Biomolecular Chemistry
|March 17, 2012
Summary
Push-pull substituted ortho-phenylene oligomers form compact helices in solution. Protonation of these helical oligomers significantly enhances their effective conjugation length and delocalization.
Area of Science:
- Organic Chemistry
- Polymer Science
- Supramolecular Chemistry
Background:
- Ortho-phenylenes are a novel class of helical oligomers and polymers.
- Push-pull substituted systems offer tunable electronic properties.
Purpose of the Study:
- To synthesize and characterize push-pull substituted ortho-phenylene oligomers.
- To investigate the impact of substituents and protonation on their helical conformation and electronic properties.
Main Methods:
- Synthesis of ortho-phenylene oligomers up to the octamer.
- Low-temperature NMR spectroscopy and ab initio calculations for conformational analysis.
- UV/vis spectroscopy and DFT calculations for electronic property evaluation.
Main Results:
- Oligomers exist as compact helices in solution, influenced by substituents.
- Protonation of the dimethylamino group favors the helical conformation.
- Protonation leads to significant bathochromic shifts and increased effective conjugation length (9 repeat units).
Conclusions:
- Substituents significantly affect ortho-phenylene helix conformation.
- Protonation dramatically enhances electronic delocalization and conjugation length.
- These findings highlight the potential of protonation for tuning the properties of helical oligomers.
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