Structure of Plastic Crystalline Succinonitrile: High‐Resolution in situ Powder Diffraction |
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Authors: | Sarmimala Hore Dr. Robert Dinnebier Dr. Wen Wen Johnathan Hanson Joachim Maier |
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Affiliation: | 1. Max Planck Institute for Solid State Research, Heisenbergstrasse 1, D‐70569 Stuttgart, Germany;2. Upton, NY 11973, USA, Department of Chemistry, Brookhaven National Laboratory |
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Abstract: | The temperature dependent (150–290 K) crystal structure of the low‐temperature α‐phase, and high temperature β‐phase, of succinonitrile has been determined by high resolution in situ powder diffraction. The α‐phase has a monoclinic unit cell that contains four gauche molecules and belongs to the P21/a space group. The crystal undergoes a reversible first‐order phase transition at 233 K into the high temperature β‐phase. The lattice parameters increase with temperature and the phase transition leads to an abrupt 6.7 % increase in volume. The β‐phase crystallizes into a bcc‐structure that belongs to the space group. The high temperature phase; however, is a highly disordered plastic crystal at room temperature that contains both gauche and trans molecules. The non‐linearity in the overall isotropic temperature‐factor indicates other possible phase transitions in the temperature range of 233–250 K. |
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Keywords: | Succinonitrile Plastic Crystal Phase Transition Crystal structures Ion Conductor |
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