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Updated: Jun 23, 2026
10:35
Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
Published on: May 29, 2018
UV/Vis to NIR photoconduction in cyclopalladated complexes.
Nicolas Godbert1, Davide Dattilo, Roberto Termine
1Centro di Eccellenza CEMIF.CAL, LASCAMM, CR-INSTM Unità della Calabria and Licryl, CNR-INFM, Department of Chemistry, University of Calabria, 87036, Arcavacata di Rende (CS), Italy.
Chemistry, an Asian Journal
|May 13, 2009
Summary
New columnar liquid crystals featuring a rigid cyclopalladated azobenzene core were synthesized. These materials exhibit promising photoconductive properties across a wide spectral range, including the near-infrared region.
Area of Science:
- Materials Science
- Organic Chemistry
- Photoconductivity
Background:
- Columnar liquid crystals are investigated for advanced electronic applications.
- Azobenzene derivatives offer unique photoresponsive properties.
- Tuning molecular energy levels is crucial for optimizing organic semiconductor performance.
Purpose of the Study:
- To synthesize novel polyalkylated cyclopalladated azobenzene Schiff base complexes.
- To characterize their liquid crystalline and photoconductive properties.
- To explore their potential as organic photoconductors, particularly in the near-infrared spectrum.
Main Methods:
- Synthesis of cyclopalladated azobenzene Schiff base complexes with peripheral alkyl chains.
- Differential scanning calorimetry and polarized optical microscopy for liquid crystal characterization.
- UV-Vis-NIR absorption spectroscopy and photoconductivity measurements.
Main Results:
- Successfully synthesized two new columnar liquid crystalline complexes (1 and 2).
- Materials exhibit liquid crystallinity from room temperature up to approximately 50°C.
- Photoconductivity measurements revealed performance comparable to reference compounds, with complex 2 showing significant activity at 760 nm.
Conclusions:
- The designed cyclopalladated azobenzene complexes are effective columnar liquid crystals.
- Polyalkylation via aryl ester or ether linkages allows tuning of HOMO/LUMO energy levels.
- Complex 2 demonstrates potential as an organic photoconductor in the near-infrared region, a rare characteristic for such materials.
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