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Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds
Published on: October 18, 2018
Polarized optical spectroscopy applied to investigate two poly(phenylene-vinylene) polymers with different side chain
Lars-Olof Pålsson1, Helen L Vaughan, Andrew P Monkman
1Photonics Materials Institute, Department of Physics, Durham University, South Road, DH1 3LE Durham, United Kingdom. lars-olof.palsson@durham.ac.uk
The Journal of Chemical Physics
|November 10, 2006
Summary
Side chain structure in poly(phenylene-vinylene) (PPV) polymers like MEH-PPV and OC1C10-PPV influences their optical properties. Differences in alignment and aggregation in films versus solutions reveal distinct electronic and optical behaviors.
Area of Science:
- Materials Science
- Polymer Chemistry
- Spectroscopy
Background:
- Poly(phenylene-vinylene) (PPV) polymers are crucial in organic electronics.
- Understanding structure-property relationships is key for optimizing light-emitting polymers.
Purpose of the Study:
- To investigate the impact of side chain structure and molecular weight on the electronic and optical properties of MEH-PPV and OC1C10-PPV.
- To explore interactions in thin films and their influence on polymer behavior.
Main Methods:
- Polarized optical spectroscopy was employed.
- Polymers were aligned using anisotropic solvents and stretched films.
- Circular dichroism (CD) spectra were analyzed in both liquid and solid states.
Main Results:
- Side chains affect transition dipole moment orientations, with differing linear dichroism in solvents versus stretched films.
- OC1C10-PPV exhibited lower luminescence polarization, suggesting distinct absorbing and emitting species.
- Solution CD spectra indicated helical conformations, while film spectra showed strong Cotton effects, indicative of aggregation.
Conclusions:
- Side chain engineering significantly impacts the optical and electronic properties of PPV polymers.
- The transition from solution to film state induces significant changes, including aggregation and altered conformations.
- Distinguishing between absorbing and emitting species is crucial for understanding luminescence in these materials.
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