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Updated: Jun 2, 2026
06:44
From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Going full circle: phase-transition thermodynamics of ionic liquids
Ulrich Preiss1, Sergey P Verevkin, Thorsten Koslowski
1Freiburger Materialforschungszentrum, Universität Freiburg, Stefan-Meier-Str. 21, 79104 Freiburg, Germany.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|May 4, 2011
Summary
We established a complete thermodynamic cycle for ionic liquids (ILs), enabling new predictions for lattice and solvation enthalpies. This work introduces improved computational methods for ILs, enhancing accuracy over existing theories.
Area of Science:
- Physical Chemistry
- Computational Chemistry
- Materials Science
Background:
- Ionic liquids (ILs) are non-classical salts with unique properties.
- Accurate determination of enthalpic phase transitions in ILs is crucial for understanding their behavior.
- Existing thermodynamic models often struggle with the complexity of ILs.
Purpose of the Study:
- To construct a full enthalpic phase transition cycle for 30 ionic liquids.
- To establish novel prediction methods for vaporization, lattice, and dissociation enthalpies of ILs.
- To determine, for the first time, lattice and solvation enthalpies for ILs containing imidazolium ions.
Main Methods:
- Utilized experimental data where available to close the thermodynamic cycle.
- Employed G3 MP2 level calculations for high-quality dissociation enthalpies.
- Developed new predictive models for vaporization (surface term + gas-phase energy correction), lattice (COSMO solvation enthalpy), and dissociation enthalpies.
Main Results:
- Successfully closed the enthalpic phase transition cycle for 30 ILs.
- Established prediction methods with significantly reduced computational time by focusing on single-ion values.
- Achieved a typical error of 9.4 kJ mol⁻¹ for lattice enthalpy, outperforming existing methods like the Kapustinskii equation and VBT theory.
Conclusions:
- Quantum-chemical calculations offer substantial improvements to Volume-Based Thermodynamics (VBT) approaches.
- The new methods provide accurate lattice and solvation enthalpies for ILs, including those with imidazolium cations.
- Proposed the term 'augmented VBT' (aVBT) for this enhanced theoretical framework.
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