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Title: Communication: Molecular dynamics and {sup 1}H NMR of n-hexane in liquid crystals

The NMR spectrum of n-hexane orientationally ordered in the nematic liquid crystal ZLI-1132 is analysed using covariance matrix adaptation evolution strategy (CMA-ES). The spectrum contains over 150 000 transitions, with many sharp features appearing above a broad, underlying background signal that results from the plethora of overlapping transitions from the n-hexane as well as from the liquid crystal. The CMA-ES requires initial search ranges for NMR spectral parameters, notably the direct dipolar couplings. Several sets of such ranges were utilized, including three from MD simulations and others from the modified chord model that is specifically designed to predict hydrocarbon-chain dipolar couplings. In the end, only inaccurate dipolar couplings from an earlier study utilizing proton-proton double quantum 2D-NMR techniques on partially deuterated n-hexane provided the necessary estimates. The precise set of dipolar couplings obtained can now be used to investigate conformational averaging of n-hexane in a nematic environment.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ; ; ;  [7]
  1. Chemistry Department, Brandon University, 270-18th Street, Brandon, Manitoba R7A 6A9 (Canada)
  2. Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1 (Canada)
  3. Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135, NL-6525 AJ Nijmegen (Netherlands)
  4. (Netherlands)
  5. Atomic, Molecular and Laser Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands)
  6. Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1 (Canada)
  7. Dipartimento di Chimica Industriale “Toso Montanari,” Università di Bologna and INSTM, viale Risorgimento 4, 40136 Bologna (Italy)
Publication Date:
OSTI Identifier:
22490861
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 1; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; COUPLINGS; HEXANE; LIQUID CRYSTALS; MOLECULAR DYNAMICS METHOD; NMR SPECTRA; NUCLEAR MAGNETIC RESONANCE; PROTONS; SIGNALS; SIMULATION