Alignment effects on high resolution nmr spectra, induced by the magnetic field

Lohman, Joost A. B.; MacLean, C.

doi:10.1016/s0301-0104(78)85242-2

Cited by 79 publications

(46 citation statements)

References 15 publications

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“…In contrast to conventional ͑nonmesogenic͒ compounds, in which the magnetic anisotropy vanishes above the melting point ͑except some very small anisotropy induced in a strong magnetic field, which can be observed in NMR spectra [25][26][27][28][29][30] ͒, in mesogenic compounds a part of the magnetic anisotropy is retained when going from the crystalline phase to the mesophase due to the alignment of long molecular axes of mol-ecules along the director n. In this section we relate the symmetry and the magnitude of the principal components of the tensor of magnetic susceptibility of the liquid-crystalline phase to those of the tensor of molecular magnetic susceptibility. The latter can be observed in a single crystal, in which metallomesogenic molecules are completely oriented.…”

Section: B Magnetic Anisotropy Of Idealized Monodomain Uniaxial Liqumentioning

confidence: 87%

On the magnetic anisotropy of lanthanide-containing metallomesogens

Mironov

Galyametdinov

Ceulemans

et al. 2000

The Journal of Chemical Physics

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A general theoretical model of the origin of the magnetic anisotropy in paramagnetic metal-containing liquid crystals is developed. General relations between the molecular magnetic anisotropy of mesogenic lanthanide complexes and the macroscopic magnetic anisotropy of these liquid crystals in the mesophase are obtained. The net magnetic anisotropy of a real metallomesogen is shown to be the result of a complex interplay between the molecular magnetic anisotropy, orientation of the long molecular axis, and disorder effects. The sign of the magnetic anisotropy ⌬ depends not only on the anisotropy of the tensor of molecular magnetic susceptibility, but also on the orientation of the long molecular axis of rodlike lanthanide complexes with respect to the principal magnetic axes of the molecular tensor of magnetic susceptibility. The influence of microand macroscopic disorder in real liquid crystals is discussed. Numerical parametric calculations were used to rationalize the variation of the magnitude and sign of the magnetic anisotropy in a series of isostructural lanthanide-containing metallomesogens. Experimental magnetic susceptibility and magnetic anisotropy of a series of ͓Ln͑LH͒ 3 ͑NO 3 ͒ 3 ͔ compounds ͑LH is a Schiff base͒ are well reproduced by calculations based on the present model. Limitations of the Bleaney theory of magnetic anisotropy are analyzed.

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Section: B Magnetic Anisotropy Of Idealized Monodomain Uniaxial Liqumentioning

confidence: 87%

On the magnetic anisotropy of lanthanide-containing metallomesogens

Mironov

Galyametdinov

Ceulemans

et al. 2000

The Journal of Chemical Physics

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“…The theory underlying dipolar and other anisotropic interactions has been described in several places, including in the early liquid crystal applications [15][16][17][18][19][20][21][22][23][24][25] as well as in more recent reviews that deal specifically with biomolecular applications. [26][27][28][29][30][31][32] Here, we provide a brief description of the basic underpinnings of the methodology, with an emphasis on its application to nucleic acids.…”

Section: Residual Dipolar Couplingsmentioning

confidence: 99%

“…Furthermore, unlike ordering media, one generally expects the diamagnetic alignment of extended nucleic acids to be negative (v zz \ 0) with the v zz direction being, on average, oriented perpendicular to the magnetic field noting that it is possible to have conformations that give rise to positive alignment (v zz [ 0). For magnetic field-induced alignment, the degree of alignment can be expressed in terms of the magnetic field strength (B 0 ), the v-tensor (in units of m 3 /molecule), and temperature (T), 15,16,24,25 …”

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confidence: 99%

Review NMR studies of RNA dynamics and structural plasticity using NMR residual dipolar couplings

et al. 2007

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An increasing number of RNAs are being discovered that perform their functions by undergoing large changes in conformation in response to a variety of cellular signals, including recognition of proteins and small molecular targets, changes in temperature, and RNA synthesis itself. The measurement of NMR residual dipolar couplings (RDCs) in partially aligned systems is providing new insights into the structural plasticity of RNA through combined characterization of large‐amplitude collective helix motions and local flexibility in noncanonical regions over a wide window of biologically relevant timescales (<milliseconds). Here, we review RDC methodology for studying RNA structural dynamics and survey what has been learnt thus far from application of these methods. Future methodological challenges are also identified. © 2007 Wiley Periodicals, Inc. Biopolymers 86: 384–402, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com

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“…and recording deuterium NMR ( 2 H NMR) spectra of solutions containing aromatic hydrocarbons having large diamagnetic anisotropies, e.g., phenanthrene-d 10 , and triphenylene-d 12 [1]. In that initial report there was no evidence of biased rotational diffusion (orientational ordering) for the molecular liquid benzene-d 6 .…”

Section: Introductionmentioning

confidence: 99%

Benzene at 1GHz. Magnetic field-induced fine structure

Heist

Poon

Samulski

et al. 2015

Journal of Magnetic Resonance

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The deuterium NMR spectrum of benzene-d 6 in a high field spectrometer (1 GHz protons) exhibits a magnetic field-induced deuterium quadrupolar splitting ν Δ . The magnitude of ν Δ observed for the central resonance is smaller than that observed for the 13 C satellite doublets ν ′ Δ . This difference,, is due to unresolved fine structure contributions to the respective resonances. We determine the origins of and simulate this difference, and report pulse sequences that exploit the connectivity of the peaks in the 13 C and 2 H spectra to determine the relative signs of the indirect coupling, CD

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Alignment effects on high resolution nmr spectra, induced by the magnetic field

Cited by 79 publications

References 15 publications

On the magnetic anisotropy of lanthanide-containing metallomesogens

On the magnetic anisotropy of lanthanide-containing metallomesogens

Review NMR studies of RNA dynamics and structural plasticity using NMR residual dipolar couplings

Benzene at 1GHz. Magnetic field-induced fine structure

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