Next Article in Journal
A Facile and Eco-Friendly Method for the Synthesis of Sulfonamide and Sulfonate Carboxylic Acid Derivatives—X-ray Structure, Hirshfeld Analysis and Spectroscopic Characterizations
Next Article in Special Issue
Improved Electronic Transport in Ion Complexes of Crown Ether Based Columnar Liquid Crystals
Previous Article in Journal
On Plowing Frictional Behavior during Scratch Testing: A Comparison between Experimental and Theoretical/Numerical Results
Previous Article in Special Issue
Phase Behaviors of Ionic Liquids Heating from Different Crystal Polymorphs toward the Same Smectic-A Ionic Liquid Crystal by Molecular Dynamics Simulation
Article Menu
Issue 1 (January) cover image

Export Article

Open AccessCommunication

Substituted Azolium Disposition: Examining the Effects of Alkyl Placement on Thermal Properties

1
Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Korea
2
Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
3
UNIST Central Research Facilities (UCRF) and School of Natural Science, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
4
Department of Chemistry, UNIST, Ulsan 44919, Korea
5
Department of Energy Engineering, UNIST, Ulsan 44919, Korea
*
Authors to whom correspondence should be addressed.
These authors contributed equally to this work.
Crystals 2019, 9(1), 34; https://doi.org/10.3390/cryst9010034
Received: 23 December 2018 / Revised: 4 January 2019 / Accepted: 6 January 2019 / Published: 11 January 2019
(This article belongs to the Special Issue Ionic Liquid Crystals)
  |  
PDF [2061 KB, uploaded 16 January 2019]
  |  

Abstract

We describe the thermal phase characteristics of a series of 4,5-bis(n-alkyl)azolium salts that were studied using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), polarized-light optical microscopy (POM), and synchrotron-based small- to wide-angle X-ray scattering (SWAXS) measurements. Key results were obtained for 1,3-dimethyl-4,5-bis(n-undecyl)imidazolium iodide (1-11), 1,3-dimethyl-4,5-bis(n-pentadecyl)imidazolium iodide (1-15), and 1,2,3-trimethyl-4,5-bis(n-pentadecyl)imidazolium iodide (2), which were found to adopt enantiotropic smectic A mesophases. Liquid-crystalline mesophases were not observed for 1,3-dimethyl-4,5-bis(n-heptyl)imidazolium iodide (1-7), 3-methyl-4,5-bis(n-pentadecyl)thiazolium iodide (3), and 2-amino-4,5-bis(n-pentadecyl)imidazolium chloride (4). Installing substituents in the 4- and 5-positions of the imidazolium salts appears to increase melting points while lowering clearing points when compared to data reported for 1,3-disubstituted analogues. View Full-Text
Keywords: liquid crystals; ionic liquid crystals; ionic liquids; imidazolium; thiazolium; mesophases liquid crystals; ionic liquid crystals; ionic liquids; imidazolium; thiazolium; mesophases
Figures

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Supplementary material

SciFeed
Printed Edition Available!
A printed edition of this Special Issue is available here.

Share & Cite This Article

MDPI and ACS Style

Goossens, K.; Rakers, L.; Shin, T.J.; Honeker, R.; Bielawski, C.W.; Glorius, F. Substituted Azolium Disposition: Examining the Effects of Alkyl Placement on Thermal Properties. Crystals 2019, 9, 34.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Crystals EISSN 2073-4352 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top