Poly(Pyridinium Salt)s Based on 2,7-Diamino-9,9-Dioctylfluorene Moieties: Synthesis, Lyotropic 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.
  • Tae S. Jo Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA.
  • Jung J. Koh Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA.
  • Jongwon Park Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA.
  • Bidyut Biswas 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.
  • Haesook Han Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway Box 454003, Las Vegas, NV 89154-4003, USA.
  • Andras F. Wacha Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Magyar Tudósok körútja 2, 1117 Budapest, Hungary.
  • Matti Knaapila Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.

DOI:

https://doi.org/10.9734/bpi/ctcb/v2/2535B

Keywords:

Poly(pyridinium salt)s, metathesis reaction, gel permeation chromatography, hairy-rod polymers, lyotropic liquid-crystalline phase, polarizing optical microscopy, SAXS, differential scanning calorimetry, thermogravimetric analysis, luminescence, UV-Vis spectroscopy, aggregation

Abstract

The phenylated poly(pyridinium salt)s are a class of ionic main-chain chain polymers  that are usually prepared by the ring-transmutation polymerization reaction of  bispyrylium salts and diamines, and metathesis reactions. They are  touted  as advanced functional materials, since they are used for the preparation of electrochromic devices, fire-retardant materials, biosensors, and even nonlinear optical devices. Here we describe a new series of poly(pyridinium salt)s that exhibit lyotropic liquid-crystalline  

and light emitting properties. A series of poly(pyridinium salt)s-fluorene main-chain ionic polymers with various organic counterions were synthesized by using ring-transmutation polymerization and metathesis reactions. Their chemical structures were characterized by Fourier Transform Infrared (FTIR), proton (1H), and fluorine 19 (19F) nuclear magnetic resonance (NMR) spectrometers. These polymers showed a number-average molecular weight (Mns) between 96.5 and 107.8 kg/mol and polydispersity index (PDI) in the range of 1.12–1.88. They exhibited fully-grown lyotropic phases in polar protic and aprotic solvents at different critical concentrations. Small-angle X-ray scattering for one polymer example indicates lyotropic structure formation for 60–80% solvent fraction. All polymers exhibited lyotropic liquid-crystalline phases in organic solvents (DMSO, CH3CN, or MeOH) above their critical concentrations, depending on the counterions. Polymer 1 was found to show a square packing motif within the observed LC platelets. The analyses of their optical properties revealed that the light emission spectra were dependent on the chemical structures of the counterions in the film states resulting in blue light, and the majority of them emitted green light in organic solvents except in a few cases they emitted blue light in THF. The size of counterions had an impact on the thermal characteristics of polymers, as measured by differential scanning calorimetry and thermogravimetric analysis. Their UV-Vis absorption spectra in various organic solvents were nearly comparable, showing that the closely spaced \(\Pi\)- \(\Pi\)*transitions were present in their conjugated polymer architectures.

Published

2022-06-08

How to Cite

Pradip K. Bhowmik, Tae S. Jo, Jung J. Koh, Jongwon Park, Bidyut Biswas, Ronald Carlo G. Principe, … Matti Knaapila. (2022). Poly(Pyridinium Salt)s Based on 2,7-Diamino-9,9-Dioctylfluorene Moieties: Synthesis, Lyotropic Liquid-crystalline and Light-emitting Properties. Current Topics on Chemistry and Biochemistry Vol. 2, 106–130. https://doi.org/10.9734/bpi/ctcb/v2/2535B

Issue

Current Topics on Chemistry and Biochemistry Vol. 2

Section

Chapters