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Title: Molecular structure of the discotic liquid crystalline phase of hexa-peri-hexabenzocoronene/oligothiophene hybrid and their charge transport properties

Abstract

Using atomistic molecular dynamics simulation, we study the discotic columnar liquid crystalline (LC) phases formed by a new organic compound having hexa-peri-Hexabenzocoronene (HBC) core with six pendant oligothiophene units recently synthesized by Nan Hu et al. [Adv. Mater. 26, 2066 (2014)]. This HBC core based LC phase was shown to have electric field responsive behavior and has important applications in organic electronics. Our simulation results confirm the hexagonal arrangement of columnar LC phase with a lattice spacing consistent with that obtained from small angle X-ray diffraction data. We have also calculated various positional and orientational correlation functions to characterize the ordering of the molecules in the columnar arrangement. The molecules in a column are arranged with an average twist of 25° having an average inter-molecular separation of ∼5 Å. Interestingly, we find an overall tilt angle of 43° between the columnar axis and HBC core. We also simulate the charge transport through this columnar phase and report the numerical value of charge carrier mobility for this liquid crystal phase. The charge carrier mobility is strongly influenced by the twist angle and average spacing of the molecules in the column.

Authors:
; ; ; ;  [1];  [2]
  1. Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States)
  2. Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309 (United States)
Publication Date:
OSTI Identifier:
22489714
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 143; Journal Issue: 14; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CHARGE TRANSPORT; CORRELATION FUNCTIONS; ELECTRIC FIELDS; HYBRIDIZATION; LIQUID CRYSTALS; MOBILITY; MOLECULAR DYNAMICS METHOD; MOLECULAR STRUCTURE; MOLECULES; ORGANIC COMPOUNDS; SIMULATION; X-RAY DIFFRACTION

Citation Formats

Bag, Saientan, Maingi, Vishal, Maiti, Prabal K., E-mail: maiti@physics.iisc.ernet.in, Yelk, Joe, Glaser, Matthew A., Clark, Noel A., and Walba, David M. Molecular structure of the discotic liquid crystalline phase of hexa-peri-hexabenzocoronene/oligothiophene hybrid and their charge transport properties. United States: N. p., 2015. Web. doi:10.1063/1.4932373.
Bag, Saientan, Maingi, Vishal, Maiti, Prabal K., E-mail: maiti@physics.iisc.ernet.in, Yelk, Joe, Glaser, Matthew A., Clark, Noel A., & Walba, David M. Molecular structure of the discotic liquid crystalline phase of hexa-peri-hexabenzocoronene/oligothiophene hybrid and their charge transport properties. United States. https://doi.org/10.1063/1.4932373
Bag, Saientan, Maingi, Vishal, Maiti, Prabal K., E-mail: maiti@physics.iisc.ernet.in, Yelk, Joe, Glaser, Matthew A., Clark, Noel A., and Walba, David M. 2015. "Molecular structure of the discotic liquid crystalline phase of hexa-peri-hexabenzocoronene/oligothiophene hybrid and their charge transport properties". United States. https://doi.org/10.1063/1.4932373.
@article{osti_22489714,
title = {Molecular structure of the discotic liquid crystalline phase of hexa-peri-hexabenzocoronene/oligothiophene hybrid and their charge transport properties},
author = {Bag, Saientan and Maingi, Vishal and Maiti, Prabal K., E-mail: maiti@physics.iisc.ernet.in and Yelk, Joe and Glaser, Matthew A. and Clark, Noel A. and Walba, David M.},
abstractNote = {Using atomistic molecular dynamics simulation, we study the discotic columnar liquid crystalline (LC) phases formed by a new organic compound having hexa-peri-Hexabenzocoronene (HBC) core with six pendant oligothiophene units recently synthesized by Nan Hu et al. [Adv. Mater. 26, 2066 (2014)]. This HBC core based LC phase was shown to have electric field responsive behavior and has important applications in organic electronics. Our simulation results confirm the hexagonal arrangement of columnar LC phase with a lattice spacing consistent with that obtained from small angle X-ray diffraction data. We have also calculated various positional and orientational correlation functions to characterize the ordering of the molecules in the columnar arrangement. The molecules in a column are arranged with an average twist of 25° having an average inter-molecular separation of ∼5 Å. Interestingly, we find an overall tilt angle of 43° between the columnar axis and HBC core. We also simulate the charge transport through this columnar phase and report the numerical value of charge carrier mobility for this liquid crystal phase. The charge carrier mobility is strongly influenced by the twist angle and average spacing of the molecules in the column.},
doi = {10.1063/1.4932373},
url = {https://www.osti.gov/biblio/22489714}, journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 14,
volume = 143,
place = {United States},
year = {Wed Oct 14 00:00:00 EDT 2015},
month = {Wed Oct 14 00:00:00 EDT 2015}
}