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Updated: Jan 15, 2026

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Planar versus Twist: Two Conformers of a 5,7,12,14-Tetrakis(triisopropylsilylethynyl)pentacene in the Solid State
Satoshi Tanaka1, Ryoko Oyama1, Mitsuharu Suzuki2
1Division of Materials Science, Nara Institute of Science and Technology (NAIST), 8916-5 Takayama-cho, Ikoma 630-0192, Japan.
Abstract:
We synthesized 4TIPS-pen, a pentacene derivative bearing TIPS-ethynyl groups at the 5,7,12,14-positions via a modified route. The compound showed polymorphism, forming green crystals with a twisted backbone and blue crystals with a planar backbone. UV-vis spectra and theoretical calculations revealed distinct optical behaviors linked to structural differences. 4TIPS-pen is photounstable, and we confirmed the product structure using X-ray analysis. These results highlight structure-property relationships and offer design guidelines for extended π-conjugated pentacenes.
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