Full conformational and energy explorations are conducted on an organic ionic plastic crystal, 1-ethyl-1-methylpyrrolidium tetrafluoroborate [C2mpyr][BF4]. The onsets of various stages of dynamic behaviour, which appear to account for low-temperature solid-solid phase transitions, are investigated by using quantum-chemical simulations. It is suggested that pseudorotation of the pyrrolidine ring occurs in the first instance; the partial rotation of the entire cation subsequently occurs and may be accompanied by reorientation of the ethyl chain as the temperature increases further. A cation-anion configuration, whereby BF4- interacts with the C2mpy cation from the side of the ring, is the most likely structure in the low-temperature phase IV region. These interpretations are supported by 13C nuclear magnetic resonance chemical-shift analysis.
|Number of pages||6|
|State||Published - 3 Nov 2014|
- Density functional calculations
- Nmr spectroscopy
- Organic ionic plastic crystal
- Solid-state electrolyte
- Structure and dynamics