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 Velayutham, Thamil Selvi 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. p. 124140. 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 degrees 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 & sdot;cm- 1, attributed to its larger molecular flexibility and improved ionic liquid mobility.
| 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, American Chemical Society (59345-ND7), National Science Foundation (NSF) (NSF-DMR-2211347), Ministry of Higher Education of Malaysia through the Fundamental Research Grant Scheme (FRGS/1/2018/STG07/UM/02/6), Carnegie Trust for the Universities of Scotland (RIG008586), Royal Society (RGS\R1\201397); (M19-0000) |
| Uncontrolled Keywords: | Ionic liquid crystals; Differential scanning calorimetry; Polarized optical microscopy; Variable temperature X-ray diffraction; Ionic conductivity; Dielectric spectroscopy |
| Subjects: | Q Science > QC Physics Q Science > QD Chemistry |
| Divisions: | Faculty of Science > Department of Physics |
| Depositing User: | Ms. Juhaida Abd Rahim |
| Date Deposited: | 06 Nov 2024 09:03 |
| Last Modified: | 06 Nov 2024 09:03 |
| URI: | http://eprints.um.edu.my/id/eprint/45635 |
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