Molecular and structural information from14N–13C dipolar couplings manifested in high resolution13C NMR spectra of solids

1982 ◽  
Vol 77 (8) ◽  
pp. 3847-3856 ◽  
Author(s):  
J. G. Hexem ◽  
M. H. Frey ◽  
S. J. Opella
Keyword(s):  
Nmr Spectra ◽  
Structural Information ◽  
Dipolar Couplings

Deuterium Quadrupolar Parameters from 1H and 2H NMR Spectra for Pyridine-d5, Benzonitrile-d5 and Chlorobenzene-d5 Using Liquid Crystal Solvents

1986 ◽  
Vol 41 (1-2) ◽  
pp. 431-435 ◽  
Author(s):  
R. Ambrosetti ◽  
D. Catalano ◽  
C. Forte ◽  
C. A. Veracini
Keyword(s):  
Liquid Crystal ◽  
Nmr Spectra ◽  
Order Parameters ◽  
Dipolar Couplings ◽  
Coupling Constants ◽  
2H Nmr ◽  
H Nmr ◽  
Quadrupolar Coupling ◽  
Asymmetry Parameters ◽  
Quadrupolar Splittings

T he quadrupolar coupling constants (DQCC) and the asymmetry parameters (η) for the ortho, meta and para deuterons in pyridine-d5, benzonitrile-d5 and chlorobenzene-d5 were determined by NMR spectroscopy in oriented phases. The 1H and 2H NMR spectra were recorded in the following solutions in liquid crystal solvents: pyridine + pyridine-d5 in PCH , in ZLI 1167 and in EBBA; benzonitrile + benzonitrile-d5 and chlorobenzene + chlorobenzene-d5 in the same solvents.The order parameters of the non-deuterated solutes in the various solutions were calculated using the dipolar couplings of the proton spectra and the rα structures taken from the literature. The same order parameters were assumed to describe also the orientation of the deuterated solute in the corresponding solutions.Each 2H spectrum yielded three quadrupolar splittings for the three different deuterated positions in the labelled solute. The splittings from the three different solutions of the same solute, together with the order parameters and the rα structure, were used to determine DQCC and η of the ortho, meta and para deuterons (Pyridine-d5: DQCCortho= 183(1) kHz, ηortho = 0.030(5), DQCCmeta = 185(1) kHz, ηmeta = 0.030(10), DQCCpara = 188(6) kHz, ηpara = 0.01(5). Benzonitrile-d5: DQCCortho = 171(12) kHz, ηortho = 0.07(3), DQCCmeta = 175(12) kHz, ηmeta = 0.05(3), DQCCpara = 176(4) kHz, ηpara = 0.10(7). Chlorobenzene-d5: DQCCortho = 180(2) kHz, ηortho = 0.06(1), DQCCmeta = 174(2) kHz, ηmeta = 0.09(3), DQCCpara= 182(4) kHz, ηPara = 0.06(4)). The results are discussed, as well as the limits and possibilities of the method used.

23Na magic-angle spinning and double-rotation NMR study of solid forms of sodium valproate

2014 ◽  
Vol 92 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Nuiok M. Dicaire ◽  
Frédéric A. Perras ◽  
David L. Bryce
Keyword(s):  
Solid State ◽  
Sodium Valproate ◽  
Nmr Spectra ◽  
Structural Information ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Multiple Quantum ◽  
Asymmetric Unit ◽  
Nmr Study ◽  
Angle Spinning

Sodium valproate is a pharmaceutical with applications in the treatment of epilepsy, bipolar disorder, and other ailments. Sodium valproate can exist in many hydrated and acid-stabilized forms in the solid state, and it can be difficult to obtain precise structural information about many of these. Here, we present a 13C and 23Na solid-state NMR study of several forms of sodium valproate, only one of which has been previously structurally characterized by single-crystal X-ray diffraction. 23Na magic-angle spinning (MAS), double-rotation (DOR), and multiple-quantum magic-angle spinning (MQMAS) NMR spectra are shown to provide useful information on the number of molecules in the asymmetric unit, the local coordination geometry of the sodium cations, and the presence of amorphous phases. Two previously identified forms are shown to be highly similar, or identical, according to the 23Na NMR data. The utility of carrying out both DOR and MQMAS NMR experiments to identify all crystallographically unique sites is demonstrated. 13C cross-polarization MAS NMR spectra also provide complementary information on the number of molecules in the asymmetric unit and the crystallinity of the sample.

Water-soluble manganese(III) corroles and corresponding (nitrido)manganese(V) complexes

2010 ◽  
Vol 14 (07) ◽  
pp. 615-620 ◽  
Author(s):  
Irena Saltsman ◽  
Israel Goldberg ◽  
Zeev Gross
Keyword(s):  
Molecular Structure ◽  
Nmr Spectra ◽  
Structural Information ◽  
Water Soluble

Corroles that carry either two or three ortho-pyridyl groups at the meso-carbon atoms form stable manganese(III) complexes, from which corresponding water-soluble derivatives are obtained via N-alkylation. These syntheses and the spectroscopic features are disclosed, together with the molecular structure of the manganese(III) corrole that carries three ortho-pyridylium groups. All the manganese(III) corroles may be transformed to stable (nitrido)manganese(V) complexes, whose NMR spectra provide invaluable structural information regarding the identity and number of atropoisomers.

scholarly journals Paramagpy: software for fitting magnetic susceptibility tensors using paramagnetic effects measured in NMR spectra

2020 ◽  
Vol 1 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Henry William Orton ◽  
Thomas Huber ◽  
Gottfried Otting
Keyword(s):  
Magnetic Susceptibility ◽  
User Interface ◽  
Metal Ions ◽  
Nmr Spectra ◽  
Residual Dipolar Couplings ◽  
Structural Information ◽  
Data Bank ◽  
Graphic User Interface ◽  
Pseudocontact Shifts ◽  
Chemical Shift Tensors

Abstract. Paramagnetic metal ions with fast-relaxing electrons generate pseudocontact shifts (PCSs), residual dipolar couplings (RDCs), paramagnetic relaxation enhancements (PREs) and cross-correlated relaxation (CCR) in the nuclear magnetic resonance (NMR) spectra of the molecules they bind to. These effects offer long-range structural information in molecules equipped with binding sites for such metal ions. Here we present the new open-source software Paramagpy, which has been written in Python 3 with a graphic user interface. Paramagpy combines the functionalities of different currently available programs to support the fitting of magnetic susceptibility tensors using PCS, RDC, PRE and CCR data and molecular coordinates in Protein Data Bank (PDB) format, including a convenient graphical user interface. Paramagpy uses efficient fitting algorithms to avoid local minima and supports corrections to back-calculated PCS and PRE data arising from cross-correlation effects with chemical shift tensors. The source code is available from https://doi.org/10.5281/zenodo.3594568 (Orton, 2019).

Measurement ofJand Dipolar Couplings from Simplified Two-Dimensional NMR Spectra

1998 ◽  
Vol 131 (2) ◽  
pp. 373-378 ◽  
Author(s):  
Marcel Ottiger ◽  
Frank Delaglio ◽  
Ad Bax
Keyword(s):  
Nmr Spectra ◽  
Dipolar Couplings ◽  
Two Dimensional

Paramagpy: Software for Fitting Magnetic Susceptibility Tensors Using Paramagnetic Effects Measured in NMR Spectra

2019 ◽  
Author(s):  
Henry Orton ◽  
Thomas Huber ◽  
Gottfried Otting
Keyword(s):  
Experimental Data ◽  
Magnetic Susceptibility ◽  
Nmr Spectra ◽  
Residual Dipolar Couplings ◽  
Paramagnetic Relaxation ◽  
Dipolar Couplings ◽  
Paramagnetic Susceptibility ◽  
Pseudocontact Shifts ◽  
Seamless Transition ◽  
Paramagnetic Relaxation Enhancements

Paramagpy is a python module for calculating paramagnetic effects in NMR spectra of proteins. This currently includes fitting of paramagnetic susceptibility tensors to experimental data associated with pseudocontact shifts (PCS) residual dipolar couplings (RDC), paramagnetic relaxation enhancements (PRE) and cross-correlated relaxation (CCR). A GUI allows easy viewing of data and seamless transition between PCS/RDC/PRE/CCR calculations.<br><br>

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