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

Authors

  • Pradip K. Bhowmik Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154-4003, USA.
  • Mohammed Kareem M. Al-Karawi Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154-4003, USA.
  • Shane T. Killarney Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154-4003, USA.
  • Erenz J. Dizon Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154-4003, USA.
  • Anthony Chang Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154-4003, USA.
  • Jongin Kim Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154-4003, USA.
  • Si L. Chen Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154-4003, USA.
  • Ronald Carlo G. Principe Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154-4003, USA.
  • Andy Ho Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154-4003, USA.
  • Haesook Han Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154-4003, USA.
  • Hari D. Mandal Department of Biology and Chemistry, Texas A & M International University, 5201 University Blvd., Laredo, TX 78041, USA.
  • Raymond G. Cortez Department of Biology and Chemistry, Texas A & M International University, 5201 University Blvd., Laredo, TX 78041, USA.
  • Bryan Gutierrez Department of Biology and Chemistry, Texas A & M International University, 5201 University Blvd., Laredo, TX 78041, USA.
  • Klarissa Mendez Department of Biology and Chemistry, Texas A & M International University, 5201 University Blvd., Laredo, TX 78041, USA.
  • Lewis Sharpnack Department of Earth Science, 1006 Webb Hall, University of California, Santa Barbara, CA 93106, USA.
  • Dena M. Agra-Kooijman Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
  • Michael R. Fisch College of Aeronautics and Engineering, Kent State University, Kent, OH 44242, USA.
  • Satyendra Kumar Division of Research, University at Albany, Albany, NY 12222, USA.

DOI:

https://doi.org/10.9734/bpi/ctcb/v2/2536B

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

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.   

Published

2022-06-08

How to Cite

Pradip K. Bhowmik, Mohammed Kareem M. Al-Karawi, Shane T. Killarney, Erenz J. Dizon, Anthony Chang, Jongin Kim, … Satyendra Kumar. (2022). Bis(4-alkoxyphenyl) Viologen Bis(triflimide) Salts: Synthesis, Thermotropic Liquid-crystalline and Light-emitting Properties . Current Topics on Chemistry and Biochemistry Vol. 2, 45–68. https://doi.org/10.9734/bpi/ctcb/v2/2536B

Issue

Current Topics on Chemistry and Biochemistry Vol. 2

Section

Chapters