Structural organization and phase behaviour of 1-butyl-3-methylimidazolium hexafluorophosphate: an high pressure Raman spectroscopy study
Related Experiment Video
Updated: Jun 1, 2026

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Olga Russina1, Barbara Fazio, Christian Schmidt
1Dipartimento di Chimica, Università di Roma, La Sapienza, P. le Aldo Moro 5, I-00185 Roma, Italy.
Abstract:
The complexity of the phase diagram of a representative room temperature ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF(6)]) is explored by means of Raman spectroscopy at high pressure (up to 1000 MPa) and high temperature (from room temperature to 100 °C) conditions. The first experimental evidence of the existence of a second crystalline phase for this salt at high pressure conditions is provided. By comparing the low frequency vibrational bands for the liquid state and the two observed crystalline phases, we confirm the scenario that considers the crystal polymorphism in this class of materials as a consequence of the rotational isomerism of the butyl chain. Furthermore the pressure dependence of other vibrational bands indicates the existence of a structural rearrangement across p≈ 50 MPa at ambient temperature.
More Related Videos
Related Concept Videos
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
VSEPR Theory and the Basic Shapes
IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations

