Bis(4-alkoxyphenyl) Viologen Bis(triflimide) Salts: Synthesis, Thermotropic Liquid-crystalline and Light-emitting Properties

Authors

Pradip K. Bhowmik Professor, University of Nevada, Las VegasFollow
Mohammed Kareem M. Al-Karawi, University of Nevada, Las Vegas
Shane T. Killarney, University of Nevada, Las Vegas
Erenz J. Dizon, University of Nevada, Las Vegas
Anthony Chang, University of Nevada, Las Vegas
Jongin Kim, University of Nevada, Las Vegas
Si Chen, University of Nevada, Las VegasFollow
Ronald Carlo G. Principe, University of Nevada, Las Vegas
Andy Ho, University of Nevada, Las Vegas
Haesook Han, University of Nevada, Las VegasFollow
Hari D. Mandal, Texas A & M International University
Raymond G. Cortez, Texas A & M International University
Bryan Gutierrez, Texas A & M International University
Klarissa Mendez, Texas A & M International University
Lewis Sharpnack, University of California, Santa Barbara
Deña M. Agra-Kooijman, Kent State University
Michael R. Fisch, Kent State University
Satyendra Kumar, State University of New York at Albany

Document Type

Book Section

Publication Date

6-8-2022

Publisher

B P International

Publisher Location

London, UK

Book Title

Current Topics on Chemistry and Biochemistry

Volume

2

First page number:

45

Last page number:

68

Abstract

Extended viologens with different organic counterions are an important class of ionic liquid crystals that combine the properties of ionic liquids and with those of liquid crystals. Here, we describe a series of extended viologen with such properties. A series of bis(4-alkoxyphenyl) viologen bis(triflimide) salts with alkoxy chains of different lengths were synthesized by the metathesis reaction of respective bis(4-alkoxyphenyl) viologen dichloride salts, which were in turn prepared from the reaction of Zincke salt with the corresponding 4-n-alkoxyanilines, with lithium triflimide in methanol. Their chemical structures were characterized by 1H and 13C Nuclear Magnetic Resonance spectra and elemental analysis. Their thermotropic liquid-crystalline (LC) properties were examined by differential scanning calorimetry, polarizing optical microscopy and variable temperature X-ray diffraction. Salts with short length alkoxy chains had crystal-to-liquid transitions. Salts of intermediate length alkoxy chains showed both crystal-to-SmA transitions, Tms, and SmA-to-isotropic transitions, Tis. Those of high length of alkoxy chains had relatively low Tms at which they formed the SmA phases that persisted up to the decomposition at high temperatures. As expected, all of them had excellent thermal stabilities in the temperature range of 330-370 C. Their light-emitting properties in methanol were also included.

Keywords

Extended viologens; Zincke salt; Metathesis reaction; Ionic liquid crystals; Thermotropic; Smectic phase A; Differential scanning calorimetry; Polarizing optical microscopy; X-ray diffraction; Thermogravimetric analysis

Disciplines

Materials Chemistry | Physical Chemistry

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

Repository Citation

Bhowmik, P. K., Al-Karawi, M. M., Killarney, S. T., Dizon, E. J., Chang, A., Kim, J., Chen, S., Principe, R. G., Ho, A., Han, H., Mandal, H. D., Cortez, R. G., Gutierrez, B., Mendez, K., Sharpnack, L., Agra-Kooijman, D. M., Fisch, M. R., Kumar, S. (2022). Bis(4-alkoxyphenyl) Viologen Bis(triflimide) Salts: Synthesis, Thermotropic Liquid-crystalline and Light-emitting Properties. , 2 45-68. London, UK: B P International.
http://dx.doi.org/10.9734/bpi/ctcb/v2/2536B