1. Structural Study of Nematogenic Compound 5OS5.
- Author
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Deptuch, Aleksandra, Sęk, Bartosz, Lalik, Sebastian, Zając, Wojciech, Ossowska-Chruściel, Mirosława D., Chruściel, Janusz, and Marzec, Monika
- Subjects
LIQUID crystal states ,POLYMER liquid crystals ,THERMAL expansion ,RIETVELD refinement ,SINGLE crystals ,DIFFERENTIAL scanning calorimetry - Abstract
The S-(4-pentylphenyl) 4-(pentyloxy)benzothioate, forming the nematic phase, is investigated by X-ray diffraction in temperatures between 263 K and 365 K, with the support of differential scanning calorimetry and polarizing optical microscopy. The microscopic observations show changes within the solid state, while X-ray diffraction does not indicate any transitions between the crystal phases. The Rietveld refinement shows that the crystal phase formed from the melt is the same monoclinic crystal phase with the P2
1 /c space group as reported for a single crystal grown from an ethanol solution. The temperature dependence of the unit cell parameters in the 263–335 K range is determined and the coefficients of thermal expansion are obtained. The unit cell expands on heating along the longer ac-diagonal and b-axis while, along the shorter ac-diagonal, a very small shrinkage occurs. The diffraction patterns of the liquid crystalline nematic phase indicate the formation of dimers via hydrogen bonding. Density functional theory calculations (def2TZVPP basis set, B3LYP-D3(BJ) correlation-exchange functional) are applied for geometry optimization of an isolated molecule and selected dimers. [ABSTRACT FROM AUTHOR]- Published
- 2024
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