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Dicyanobenzothiadiazole Derivatives Possessing Switchable Dielectric Permittivities
Jakob Wudarczyk1, George Papamokos2, Tomasz Marszalek1
1Max Planck Institute for Polymer Research , Ackermannweg 10, D-55128 Mainz, Germany.
ACS Applied Materials & Interfaces
|June 1, 2017
Summary
Dicyanobenzothiadiazole (DCNBT) molecules exhibit tunable dielectric properties, with nitrile groups enhancing dipole moments. These materials show promising dielectric permittivity switching in liquid crystalline phases, rivaling established rodlike liquid crystals.
Area of Science:
- Materials Science
- Organic Electronics
- Supramolecular Chemistry
Background:
- Benzothiadiazoles are key electron-deficient building blocks for donor-acceptor polymers.
- Nitrile functionalities significantly influence molecular properties and performance in organic electronic materials.
Purpose of the Study:
- To investigate the impact of nitrile groups on dicyanobenzothiadiazole (DCNBT) properties.
- To explore the dielectric permittivity and self-assembly behavior of DCNBT derivatives.
- To engineer DCNBT for enhanced dipole moments and dielectric performance.
Main Methods:
- Density Functional Theory (DFT) calculations for molecular modeling.
- Dielectric spectroscopy to measure bulk and solution permittivity.
- X-ray scattering (2D-WAXS, GiWAXS) for analyzing self-assembly in various forms (crystals, fibers, thin films).
Main Results:
- Nitrile groups in DCNBT significantly increase dipole moment and dielectric permittivity.
- Self-assembly behavior was characterized across different phases.
- A notable switching of dielectric permittivity was observed in 4,7-alkylthienyl-substituted DCNBT at the liquid crystalline to isotropic phase transition.
Conclusions:
- DCNBT molecules can be precisely engineered via nitrile functionalization to achieve high dielectric permittivity.
- The observed dielectric switching behavior suggests potential applications in advanced electronic devices.
- These DCNBT derivatives offer competitive dielectric performance compared to state-of-the-art rodlike liquid crystals.
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