Nuclear magnetic resonance of xenon-131 in a poly-γ-benzyl-l-glutamate liquid crystalline solution

Loewenstein, A.; Brenman, M.

doi:10.1016/0009-2614(78)85069-6

Cited by 30 publications

(15 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In single crystals and macroscopically oriented liquid crystals, all of the domains have the same residual EFGs and are parallel (24,25). If the ions/molecules are constrained within the domains and the domains are randomly oriented with respect to B 0 (but having the same residual EFGs and ), the NMR spectrum has the well-known "Pake powder" characteristics (21,26).…”

Section: Modeling Of the Biological Samplementioning

confidence: 98%

“…Provided that the RF pulse widths are short compared to the transverse relaxation times, the signal at the end of the DQ-MA filter can be expressed as (29) A nonlinear fit of the DQ-MA data to Eq. [24], using the Levenberg-Marquardt algorithm, was used for every value of the preparation time to yield values for Q , , and T 2f .…”

Section: Determination Of Sample Characteristicsmentioning

confidence: 99%

See 1 more Smart Citation

A Model for the Dynamics of Spins 3/2 in Biological Media: Signal Loss during Radiofrequency Excitation in Triple-Quantum-Filtered Sodium MRI

Hancu

Maarel

Boada

2000

Journal of Magnetic Resonance

View full text Add to dashboard Cite

Section: Modeling Of the Biological Samplementioning

confidence: 98%

Section: Determination Of Sample Characteristicsmentioning

confidence: 99%

A Model for the Dynamics of Spins 3/2 in Biological Media: Signal Loss during Radiofrequency Excitation in Triple-Quantum-Filtered Sodium MRI

Hancu

Maarel

Boada

2000

Journal of Magnetic Resonance

View full text Add to dashboard Cite

“…[40][41][42] Both nonrigid effects have been shown to make significant contributions to dipolar couplings. For example, the splittings observed in the 1 H NMR spectrum of methane as solute in nematic solvents 43 are a dramatic example of the effect of vibrationreorientation interaction. 40 The importance of this interaction and the difficulties involved in estimating this effect, in general, have been explored with spectra of solutes in several nematic solvents with the solutes azulene and biphenylene as examples.…”

Section: Theoretical Backgroundmentioning

confidence: 99%

A model-free temperature-dependent conformational study of n-pentane in nematic liquid crystals

Burnell

Weber

Dong

et al. 2015

The Journal of Chemical Physics

View full text Add to dashboard Cite

The proton NMR spectra of n-pentane orientationally ordered in two nematic liquid-crystal solvents are studied over a wide temperature range and analysed using covariance matrix adaptation evolutionary strategy. Since alkanes possess small electrostatic moments, their anisotropic intermolecular interactions are dominated by short-range size-and-shape effects. As we assumed for n-butane, the anisotropic energy parameters of each n-pentane conformer are taken to be proportional to those of ethane and propane, independent of temperature. The observed temperature dependence of the n-pentane dipolar couplings allows a model-free separation between conformer degrees of order and conformer probabilities, which cannot be achieved at a single temperature. In this way for n-pentane 13 anisotropic energy parameters (two for trans trans, tt, five for trans gauche, tg, and three for each of gauche + gauche + , pp, and gauche + gauche − , pm), the isotropic trans-gauche energy difference E tg and its temperature coefficient E ′ tg are obtained. The value obtained for the extra energy associated with the proximity of the two methyl groups in the gauche + gauche − conformers (the pentane effect) is sensitive to minute details of other assumptions and is thus fixed in the calculations. Conformer populations are affected by the environment. In particular, anisotropic interactions increase the trans probability in the ordered phase. C 2015 AIP Publishing LLC. [http://dx

show abstract

“…14 N NMR spectra of molecular nitrogen in SDS/pentanol swollen lamellar phases solvents, where the gas is more soluble, namely CDCl 3 [12] and formamide, [13] and, just recently, bicelles of phospholipids in water. [14] Here, we propose the application of N 2 as an NMR molecular probe in lyotropic systems.…”

Section: S81mentioning

confidence: 99%

14N NMR spectra of molecular nitrogen in SDS/pentanol swollen lamellar phases

Pellizer

Asaro

2008

Magn. Reson. Chem.

View full text Add to dashboard Cite

14N NMR spectra of air dissolved in lyotropic mesophases are reported. In order to observe the whole spectrum from a molecule in which the quadrupole coupling constant is on the order of a few megahertz, a weak alignment degree with respect to the magnetic field is mandatory. Therefore, dilute lyotropic liquid crystals, namely sodium dodecylsulphate (SDS)/pentanol swollen lamellar phases, were considered. The temperature dependence of the 14N quadrupolar splitting was followed both in the case of oil (either n-dodecane or n-heptane) and brine (a 0.2-M NaBr water solution) swelling. In the former, it paralleled the temperature dependence of the splittings of the alkane deuteria and, in both cases, it was opposite to 23Na quadrupolar splittings. Owing to the higher N2 solubility in hydrocarbons, the 14N NMR spectra provide complementary information to that obtained by means of the quadrupolar nuclei of water and hydrophilic solutes.

show abstract

Nuclear magnetic resonance of xenon-131 in a poly-γ-benzyl-l-glutamate liquid crystalline solution

Cited by 30 publications

References 6 publications

A Model for the Dynamics of Spins 3/2 in Biological Media: Signal Loss during Radiofrequency Excitation in Triple-Quantum-Filtered Sodium MRI

A Model for the Dynamics of Spins 3/2 in Biological Media: Signal Loss during Radiofrequency Excitation in Triple-Quantum-Filtered Sodium MRI

A model-free temperature-dependent conformational study of n-pentane in nematic liquid crystals

14N NMR spectra of molecular nitrogen in SDS/pentanol swollen lamellar phases

Contact Info

Product

Resources

About