Multinuclear NMR relaxometry studies in singly fluorinated liquid crystal

Rajeswari, M.; Molugu, Trivikram R.; Dhara, Surajit; Venu, K.; Sastry, V. S. S.; Dąbrowski, R.

doi:10.1016/j.cplett.2012.02.010

Cited by 9 publications

(6 citation statements)

References 24 publications

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“…This is discussed further below. A recent work40 nicely summarizes the various interactions that19 F spins can be involved with for a liquid crystal with many kinds of motionssome of them quite slowand shows why, at 22.5 MHz in a polycrystalline powder, we are not concerned with the spin rotation or chemical shift interactions for either 1 H or19 F relaxation. The NMR frequencies for 1 H and19 F are close enough that, with a little help from the thermal bath of phonons, mutual spin flips can occur via the 1 H  19 F interactions.…”

mentioning

confidence: 99%

Nonexponential Solid State ¹H and ¹⁹F Spin–Lattice Relaxation, Single-crystal X-ray Diffraction, and Isolated-Molecule and Cluster Electronic Structure Calculations in an Organic Solid: Coupled Methyl Group Rotation and Methoxy Group Libration in 4,4′-Dimethoxyoctafluorobiphenyl

et al. 2012

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We investigate the relationship between intramolecular rotational dynamics and molecular and crystal structure in 4,4'-dimethoxyoctafluorobiphenyl. The techniques are electronic structure calculations, X-ray diffractometry, and (1)H and (19)F solid state nuclear magnetic resonance relaxation. We compute and measure barriers for coupled methyl group rotation and methoxy group libration. We compare the structure and the structure-motion relationship in 4,4'-dimethoxyoctafluorobiphenyl with the structure and the structure-motion relationship in related compounds in order to observe trends concerning the competition between intramolecular and intermolecular interactions. The (1)H spin-lattice relaxation is nonexponential in both the high-temperature short-correlation time limit and in the low-temperature long-correlation time limit, albeit for different reasons. The (19)F spin-lattice relaxation is nonexponential at low temperatures and it is exponential at high temperatures.

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confidence: 99%

Nonexponential Solid State ¹H and ¹⁹F Spin–Lattice Relaxation, Single-crystal X-ray Diffraction, and Isolated-Molecule and Cluster Electronic Structure Calculations in an Organic Solid: Coupled Methyl Group Rotation and Methoxy Group Libration in 4,4′-Dimethoxyoctafluorobiphenyl

et al. 2012

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“…The same group reported also a related study of another related singly-fluorinated LC-former. 189 Chavez et al 190 reported a study of Larmor frequency and temperature dependence of 1 H spin-lattice relaxation time in disc-like triphenylene molecules with alkyl and fluoroalkylated substituents. The systems were studied in isotropic liquid and columnar phases.…”

Section: Pure Liquidsmentioning

confidence: 99%

Nuclear spin relaxation in liquids and gases

Kowalewski¹

2013

Nuclear Magnetic Resonance

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This report reviews the progress in the field of NMR relaxation in fluids. The emphasis is on comparatively simple liquids and solutions of physico-chemical and chemical interest, in analogy with the previous periods, but selected biophysicsrelated topics and relaxation-related work on more complex systems (macromolecular solutions, liquid crystalline systems, glassy and porous materials) are also covered. The period under review is from June 2011 through May 2012. Some earlier works, overlooked in last year's chapter, are also included. The outline of this chapter is as follows: section 2 which follows the introduction covers the general, physical and experimental aspects of nuclear spin relaxation in liquids and is further divided in seven subsections. The first two are fairly general and the following three discuss more specific aspects of spin-1/2 systems. The last two subsections cover quadrupolar nuclei and paramagnetic systems, respectively. Section 3 deals with applications of NMR relaxation in liquids, starting with pure liquids and continuing with solutions of low-molecular weight compounds. It also includes a selection of works on solutions of biological macromolecules and other complex systems. The progress in the field of relaxation in gases is described in section 4.

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“…To this end, 19 F NMR spectra were recorded on the samples in the I and N phases, and analyzed. 19 F NMR T 1 frequency dispersion has recently been measured in the I phase of a singly fluorinated LC 4 0 -butoxy-3-fluoro-4-isothiocyantotolane (4OTOLFo) and contrasted with proton T 1 frequency dispersion at the same temperature [265]. In particular, 19 F spin can detect slowly relaxing local structures via its spin-rotation interaction.…”

Section: Calamitics and Hydrogen-bonded Mesogensmentioning

confidence: 99%

Recent NMR Studies of Thermotropic Liquid Crystals

Dong¹

2016

Annual Reports on NMR Spectroscopy

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Multinuclear NMR relaxometry studies in singly fluorinated liquid crystal

Cited by 9 publications

References 24 publications

Nonexponential Solid State ¹H and ¹⁹F Spin–Lattice Relaxation, Single-crystal X-ray Diffraction, and Isolated-Molecule and Cluster Electronic Structure Calculations in an Organic Solid: Coupled Methyl Group Rotation and Methoxy Group Libration in 4,4′-Dimethoxyoctafluorobiphenyl

Nonexponential Solid State ¹H and ¹⁹F Spin–Lattice Relaxation, Single-crystal X-ray Diffraction, and Isolated-Molecule and Cluster Electronic Structure Calculations in an Organic Solid: Coupled Methyl Group Rotation and Methoxy Group Libration in 4,4′-Dimethoxyoctafluorobiphenyl

Nuclear spin relaxation in liquids and gases

Recent NMR Studies of Thermotropic Liquid Crystals

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Multinuclear NMR relaxometry studies in singly fluorinated liquid crystal

Cited by 9 publications

References 24 publications

Nonexponential Solid State 1H and 19F Spin–Lattice Relaxation, Single-crystal X-ray Diffraction, and Isolated-Molecule and Cluster Electronic Structure Calculations in an Organic Solid: Coupled Methyl Group Rotation and Methoxy Group Libration in 4,4′-Dimethoxyoctafluorobiphenyl

Nonexponential Solid State 1H and 19F Spin–Lattice Relaxation, Single-crystal X-ray Diffraction, and Isolated-Molecule and Cluster Electronic Structure Calculations in an Organic Solid: Coupled Methyl Group Rotation and Methoxy Group Libration in 4,4′-Dimethoxyoctafluorobiphenyl

Nuclear spin relaxation in liquids and gases

Recent NMR Studies of Thermotropic Liquid Crystals

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Product

Resources

About

Nonexponential Solid State ¹H and ¹⁹F Spin–Lattice Relaxation, Single-crystal X-ray Diffraction, and Isolated-Molecule and Cluster Electronic Structure Calculations in an Organic Solid: Coupled Methyl Group Rotation and Methoxy Group Libration in 4,4′-Dimethoxyoctafluorobiphenyl

Nonexponential Solid State ¹H and ¹⁹F Spin–Lattice Relaxation, Single-crystal X-ray Diffraction, and Isolated-Molecule and Cluster Electronic Structure Calculations in an Organic Solid: Coupled Methyl Group Rotation and Methoxy Group Libration in 4,4′-Dimethoxyoctafluorobiphenyl