Next Article in Journal
Stereochemistry of Simple Molecules inside Nanotubes and Fullerenes: Unusual Behavior of Usual Systems
Previous Article in Journal
Inhibitory Effects of AF-343, a Mixture of Cassia tora L., Ulmus pumila L., and Taraxacum officinale, on Compound 48/80-Mediated Allergic Responses in RBL-2H3 Cells
Previous Article in Special Issue
Optical Textures and Orientational Structures in Cholesteric Droplets with Conical Boundary Conditions
Open AccessArticle

Thermotropic Liquid-Crystalline and Light-Emitting Properties of Bis(4-aalkoxyphenyl) Viologen Bis(triflimide) Salts

1
Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA
2
Department of Biology and Chemistry, Texas A & M International University, 5201 University Blvd., Laredo, TX 78041, USA
3
Department of Earth Science, 1006 Webb Hall, University of California, Santa Barbara, CA 93106, USA
4
Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA
5
College of Aeronautics and Engineering, Kent State University, Kent, OH 44242, USA
6
Division of Research, University at Albany, Albany, NY 12222, USA
*
Author to whom correspondence should be addressed.
Academic Editor: Roberta Cassano
Molecules 2020, 25(10), 2435; https://doi.org/10.3390/molecules25102435
Received: 28 April 2020 / Revised: 21 May 2020 / Accepted: 21 May 2020 / Published: 23 May 2020
(This article belongs to the Special Issue Current Advances in Liquid Crystals)
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-smectic A (SmA) transitions, Tms, and SmA-to-isotropic transitions, Tis. Those with longer 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. View Full-Text
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 extended viologens; Zincke salt; metathesis reaction; ionic liquid crystals; thermotropic; smectic phase A; differential scanning calorimetry; polarizing optical microscopy; X-ray diffraction; thermogravimetric analysis
Show Figures

Graphical abstract

MDPI and ACS Style

Bhowmik, P.K.; Al-Karawi, M.K.M.; Killarney, S.T.; Dizon, E.J.; Chang, A.; Kim, J.; Chen, S.L.; Principe, R.C.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. Thermotropic Liquid-Crystalline and Light-Emitting Properties of Bis(4-aalkoxyphenyl) Viologen Bis(triflimide) Salts. Molecules 2020, 25, 2435.

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.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop