title: Do solid-to-solid polymorphic transitions in DL-norleucine proceed through nucleation?
abstract: DL-Norleucine is a molecular crystal exhibiting two enantiotropic phase transitions. The high temperature α ↔ γ transition has been shown to proceed through nucleation and growth [Mnyukh et al., J. Phys. Chem. Solids, 1975, 36, 127]. We focus on the low temperature β ↔ α transition in a combined computational and experimental study. The temperature dependence of the structural and energetic properties of both polymorphic forms is nearly identical. Molecular dynamics simulations and nudged elastic band calculations of the transition process itself, suggest that the transition is governed by cooperative movements of bilayers over relatively large energy barriers.
authors.affiliation: Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands. h.cuppen@science.ru.nl.
authors.forename: Joost A
authors.initials: JA
authors.lastname: van den Ende
authors.forename: Mireille M H
authors.initials: MM
authors.lastname: Smets
authors.forename: Daniël T
authors.initials: DT
authors.lastname: de Jong
authors.forename: Sander J T
authors.initials: SJ
authors.lastname: Brugman
authors.forename: Bernd
authors.initials: B
authors.lastname: Ensing
authors.forename: Paul T
authors.initials: PT
authors.lastname: Tinnemans
authors.forename: Hugo
authors.initials: H
authors.lastname: Meekes
authors.forename: Herma M
authors.initials: HM
authors.lastname: Cuppen
mesh_terms: D003460:Crystallization; D056004:Molecular Dynamics Simulation; D009646:Norleucine / Q000737:chemistry*; D013237:Stereoisomerism; D013696:Temperature
chemical_list: D009646:Norleucine