title: Insight into local structure and molecular dynamics in organic solid-state ionic conductors.
abstract: Elucidating the rate and geometry of molecular dynamics is particularly important for unravelling ion-conduction mechanisms in electrochemical materials. The local molecular motions in the plastic crystal 1-ethyl-1-methylpyrrolidinium tetrafluoroborate ([C2 mpyr][BF4 ]) are studied by a combination of quantum chemical calculations and advanced solid-state nuclear magnetic resonance spectroscopy. For the first time, a restricted puckering motion with a small fluctuation angle of 25° in the pyrrolidinium ring has been observed, even in the low-temperature phase (-45 °C). This local molecular motion is deemed to be particularly important for the material to maintain its plasticity, and hence, its ion mobility at low temperatures.
authors.affiliation: Institute for Frontier Materials and ARC Centre of Excellence for Electromaterials Science, Deakin University, Geelong, VIC 3216 (Australia).
authors.forename: Haijin
authors.initials: H
authors.lastname: Zhu
authors.forename: Fangfang
authors.initials: F
authors.lastname: Chen
authors.forename: Liyu
authors.initials: L
authors.lastname: Jin
authors.forename: Luke A
authors.initials: LA
authors.lastname: O'Dell
authors.forename: Maria
authors.initials: M
authors.lastname: Forsyth
keywords: NMR spectroscopy; chemical shift anisotropy; molecular dynamics; plastic crystals; quantum chemical calculations