LIU, HUIYU (2016) Structural investigations of chloranilic acid pyrazine cocrystal and ferroelectric 2-methylbenzimidazole. Masters thesis, Durham University.
The purpose of the project was to determine the crystal structures at variable temperatures and investigate the potential structural phase transitions in chloranilic acid pyrazine cocrystal and single-component ferroelectric 2-methylbenzimidazole. The crystal structure of chloranilic acid pyrazine at 120 K was triclinic, P-1, with a=4.7684(2) Å, b=5.8402(3) Å, c=10.6897(5) Å, α=82.038(4)°, β=81.568(4)°, γ=76.938(4)°. It undergoes a phase transition from monoclinic space group C2/m to triclinic space group P-1. We used ideas of rigid bodies and distortion-mode amplitudes to understand what drives the phase transition. The crystal structure of 2-methylbenzimidazole was explored by variable temperature powder and single crystal X-ray diffraction, as well as by variable temperature solid-state NMR and proton spectra calculations. The crystal structure did not change between 120 K and 400 K and was likely to be monoclinic space group Pn.
|Item Type:||Thesis (Masters)|
|Award:||Master of Science|
|Faculty and Department:||Faculty of Science > Chemistry, Department of|
|Copyright:||Copyright of this thesis is held by the author|
|Deposited On:||08 Dec 2016 10:20|