Journal article
INTERCONVERSION KINETICS AND ORDERING OF 1,4-DIMETHYLCYCLOHEXANE AND 1,1-DIMETHYLCYCLOHEXANE IN LIQUID-CRYSTALLINE SOLUTIONS BY 1D AND 2D DEUTERIUM NMR
Liquid Crystals, Vol.11(4), pp.547-560
Apr/1992
Abstract
Deuterium NMR spectra of perdeuteriated 1,4-dimethylcyclohexane-d16 and 1,1-dimethylcyclohexane-d16 dissolved in the nematic solvent ZLI2452 are reported ported for the temperature range -40 to +80-degrees-C. Between -30 and +60-degrees-C the spectra exhibit characteristic exchange broadening and coalescence due to the ring inversion process. In the extreme slow exchange regime, peak assignment and determination of relative signs of the deuterium quadrupole interactions were made using 2D exchange spectroscopy and structural parameters derived from molecular mechanics calculations. In the intermediate temperature range the lineshapes were interpreted quantitatively in terms of the ring interconversion kinetics yielding the kinetic equations, k = 1.38 x 10(13) exp(-45.2/RT) s-1 for 1,4-dimethylcyclohexane, and k = 4.05 x 10(13) exp(-49.0/RT)s-1 for 1,1-dimethylcyclohexane, where R is in kJ mol-1. The complete ordering matrix of both compounds was determined over the whole temperature range of the measurements.
Details
- Title
- INTERCONVERSION KINETICS AND ORDERING OF 1,4-DIMETHYLCYCLOHEXANE AND 1,1-DIMETHYLCYCLOHEXANE IN LIQUID-CRYSTALLINE SOLUTIONS BY 1D AND 2D DEUTERIUM NMR
- Creators
- K MULLER (null)Zeev Luz (null) - The Weizmann Institute of ScienceR POUPKO (null)H ZIMMERMANN (null)
- Resource Type
- Journal article
- Publication Details
- Liquid Crystals, Vol.11(4), pp.547-560; Apr/1992
- Number of pages
- 14
- Language
- English
- DOI
- https://doi.org/10.1080/02678299208029009
- Scientific Unit
- The Weizmann Institute of Science
- Record Identifier
- 993267582203596
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