Bhowmik, Pradip K. and Chen, Si L. and King, David and Han, Haesook and Bolyard, Zane and Schmiedl, Christopher and Fisch, Michael R. and Gopal, Sanjeev Raj and Selvi Velayutham, Thamil and Martinez-Felipe, Alfonso (2024) Dicationic ionic liquid crystals: Synthesis, characterization, optical properties, and ionic conductivity of bis(4-oligoethyleneoxyphenyl) viologen bistosylate salts. Journal of Molecular Liquids, 398. ISSN 0167-7322, DOI https://doi.org/10.1016/j.molliq.2024.124140.
Full text not available from this repository.Abstract
Three bis(4-oligoethyleneoxyphenyl) viologen bistosylate salts of different lengths were prepared via the Zincke reaction followed by a metathesis reaction with silver tosylate, and their chemical structures confirmed by 1H, 13C nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) techniques, and elemental analysis. Thermogravimetric analysis (TGA) showed these salts had excellent thermal stabilities, losing just 5 of their initial mass between 283 and 288 °C. Liquid crystalline phases and transition temperatures were determined by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and variable temperature X-ray diffraction (VTXRD) techniques. The salts exhibited weak fluorescent emission in dichloromethane and no emission in acetonitrile but exhibited light emission in the solid state. Their absolute quantum yields ranged between 3 and 12 . Impedance spectroscopy showed that the ionic conductivity of the salts increases with the number of oxyethylene units in the extended viologen moiety. The salt-containing four oxyethylene units at each end reach a conductivity value of 10-2 S·cm−1, attributed to its larger molecular flexibility and improved ionic liquid mobility. © 2024 Elsevier B.V.
| Item Type: | Article |
|---|---|
| Funders: | University of Nevada Las Vegas (UNLV), Faculty Opportunity Award (FOA) that is adminis-tered by the Office of Sponsored Programs (OSP) at UNLV |
| Uncontrolled Keywords: | Dichloromethane; Differential scanning calorimetry; Fourier transform infrared spectroscopy; Ionic conductivity; Ionic liquids; Liquid crystals; Nuclear magnetic resonance; Optical data storage; Optical microscopy; Optical properties; Salts; Silicones; Sulfur compounds; Thermogravimetric analysis; Dicationic ionic liquids; Ionic liquid crystals; Liquid crystal synthesis; Metathesis reactions; Oxyethylene; Polarized optical microscopy; Variable temperature; Variable temperature X-ray diffraction; Viologens; X- ray diffractions; X ray diffraction |
| Subjects: | Q Science > QD Chemistry |
| Divisions: | Faculty of Science > Department of Physics |
| Depositing User: | Ms. Juhaida Abd Rahim |
| Date Deposited: | 09 Jul 2024 08:45 |
| Last Modified: | 09 Jul 2024 08:45 |
| URI: | http://eprints.um.edu.my/id/eprint/44729 |
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