Indirect Spin–Spin Coupling in InP Investigated by Triple-Resonance NMR under Magic-Angle Spinning

2004 ◽  
Vol 73 (4) ◽  
pp. 1045-1049 ◽  
Author(s):  
Takahiro Iijima ◽  
Kenjiro Hashi ◽  
Atsushi Goto ◽  
Tadashi Shimizu ◽  
Shinobu Ohki
Keyword(s):  
Magic Angle Spinning ◽  
Spin Coupling ◽  
Magic Angle ◽  
Triple Resonance ◽  
Triple Resonance Nmr ◽  
Angle Spinning ◽  
Spin Spin Coupling

Article

1999 ◽  
Vol 77 (11) ◽  
pp. 1962-1972
Author(s):  
Scott Kroeker ◽  
Roderick E Wasylishen
Keyword(s):  
Nmr Spectra ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Spin Coupling ◽  
Group Symmetry ◽  
Magic Angle ◽  
Chemical Shielding ◽  
Shielding Tensor ◽  
Angle Spinning ◽  
Spin Spin Coupling

Direct NMR observation of copper-63/65 nuclei in solid K3Cu(CN)4 provides the first experimental example of anisotropic copper chemical shielding. Axially symmetric by virtue of the space group symmetry, the shielding tensor spans 42 ppm, with the greatest shielding when the unique axis is perpendicular to the applied magnetic field. The nuclear quadrupole coupling constant is also appreciable, CQ(63Cu) = -1.125 MHz, reflecting a deviation of the Cu(CN)43- anion from pure tetrahedral symmetry. Spin-spin coupling to 13C nuclei in an isotopically enriched sample is quantified by line-shape simulations of both 13C and 63/65Cu magic-angle spinning (MAS) NMR spectra to be 300 Hz. It is shown that this information is also directly available by 63/65Cu triple-quantum (3Q) MAS NMR. The relative merits of these three approaches to characterizing spin-spin couplings involving half-integer quadrupolar nuclei are discussed. Chemical shielding tensors for nitrogen-15 and carbon-13 are obtained from NMR spectra of non-spinning samples, and are compared to those of tetrahedral group 12 tetracyanometallates. Finally, 2J(63/65Cu,15N) detected in 15N MAS experiments are found to be 19 and 20 Hz for the two crystallographically distinct cyanide ligands.Key words: NMR, quadrupolar nucleus, chemical shielding tensor, multiple-quantum magic-angle spinning, metal cyanide, spin-spin coupling.

X-ray diffraction and solid-state 119Sn CP-MAS NMR studies of some triaryltin(IV) chlorides

2003 ◽  
Vol 81 (11) ◽  
pp. 1187-1195 ◽  
Author(s):  
Jordan M Geller ◽  
Ian S Butler ◽  
Denis FR Gilson ◽  
Frederick G Morin ◽  
Ivor Wharf ◽  
...  
Keyword(s):  
Solid State ◽  
Chemical Shift ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Spin Coupling ◽  
Magic Angle ◽  
X Ray ◽  
Tin Chloride ◽  
Angle Spinning ◽  
Spin Spin Coupling

The solid-state 119Sn cross-polarization (CP) magic angle spinning (MAS) NMR spectra of a series of triaryltin chlorides of the form Ar3SnCl have been acquired. The indirect spin-spin coupling constants (J(119Sn-35Cl)), quadrupolar-dipolar shifts (d(119Sn-35Cl)), and the 119Sn chemical shift tensors were extracted. For the spectrum of triphenyltin chloride (I) the validity of the first-order perturbation approximation was tested by comparing results of both the perturbation and cubic-equation approaches and a variable-temperature NMR study undertaken to investigate the influence of the previously reported molecular motion in the solid. The X-ray crystal structures of the tris(o-tolyl)tin chloride (II) and tris(p-tolyl)tin chloride (IV) complexes have been examined. They belong to the monoclinic and triclinic space groups P21/n and P[Formula: see text], respectively, which are different from the previously reported tris(m-tolyl)tin chloride (III) complex, which crystallizes in the space group R3 and has threefold molecular symmetry. The structures and NMR properties of the complexes with meta-substituents are quite different from those with ortho- or para-substituents having axially symmetric shift tensors with small spans and larger J values.Key words: aryltin chlorides, magic angle spinning NMR, tin-chlorine spin-spin coupling, 119Sn chemical shift tensor, crystal structure.

High resolution triple resonance micro magic angle spinning NMR spectroscopy of nanoliter sample volumes

2016 ◽  
Vol 18 (6) ◽  
pp. 4902-4910 ◽  
Author(s):  
J. Ole Brauckmann ◽  
J. W. G. (Hans) Janssen ◽  
Arno P. M. Kentgens
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
High Resolution ◽  
Single Crystals ◽  
Solid State Nmr ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Triple Resonance ◽  
Angle Spinning

To be able to study mass-limited samples and small single crystals, a triple resonance micro-magic angle spinning (μMAS) probehead for the application of high-resolution solid-state NMR of nanoliter samples was developed.

scholarly journals Solid-State Protein-Structure Determination with Proton-Detected Triple-Resonance 3D Magic-Angle-Spinning NMR Spectroscopy

2007 ◽  
Vol 46 (44) ◽  
pp. 8380-8383 ◽  
Author(s):  
Donghua H. Zhou ◽  
John J. Shea ◽  
Andrew J. Nieuwkoop ◽  
W. Trent Franks ◽  
Benjamin J. Wylie ◽  
...  
Keyword(s):  
Protein Structure ◽  
Solid State ◽  
Nmr Spectroscopy ◽  
Structure Determination ◽  
Protein Structure Determination ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Triple Resonance ◽  
Angle Spinning

An unusually large value of 1J(31P,31P) for a solid triphenylphosphine phosphadiazonium cationic complex: determination of the sign of J from 2D spin-echo experiments

1996 ◽  
Vol 74 (11) ◽  
pp. 2372-2377 ◽  
Author(s):  
Klaus Eichele ◽  
Roderick E. Wasylishen ◽  
Robert W. Schurko ◽  
Neil Burford ◽  
W. Alex Whitla
Keyword(s):  
Chemical Shift ◽  
Spin Echo ◽  
Magic Angle Spinning ◽  
Convincing Evidence ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Chemical Shift Tensor ◽  
Magic Angle ◽  
Molecular Orbital Calculations ◽  
Angle Spinning

Phosphorus-31 NMR spectra of a solid triphenylphosphine phosphadiazonium salt, [Mes*NP-PPh3][SO3CF3], have been acquired at 4.7 and 9.4 T. Analysis of the spectra obtained with magic-angle spinning indicates that the two phosphorus nuclei are strongly spin–spin coupled, [Formula: see text], despite the unusually long P—P separation, rP,P = 2.625 Å. Two-dimensional spin-echo spectra provide convincing evidence that 1J(31P,31P) is negative. Semi-empirical molecular orbital calculations at the INDO level support the negative sign for 1J(31P,31P). A large span, 576 ppm, is observed for the chemical shift tensor of the two-coordinate phosphorus centre (δ11 = 307 ppm, δ22 = 174 ppm, δ33 = −269 ppm), which is very similar to the value previously reported for the non-coordinated phosphorus centre in the free Lewis acid, [Mes*NP][AlCl4]. The principal components and orientations of the phosphorus shielding tensors of these compounds are compared with those calculated for [HNP]+ and its phosphine adduct using the ab initio Gauge-Including Atomic Orbitals method. The phosphorus chemical shift tensor of the triphenylphosphine moiety has a relatively small span of 33 ppm. Key words: spin–spin coupling constants, solid-state NMR, 31P NMR, MO calculations, phosphadiazonium cation, P—P bonds.

Solid-State Protein-Structure Determination with Proton-Detected Triple-Resonance 3D Magic-Angle-Spinning NMR Spectroscopy

2007 ◽  
Vol 119 (44) ◽  
pp. 8532-8535 ◽  
Author(s):  
Donghua H. Zhou ◽  
John J. Shea ◽  
Andrew J. Nieuwkoop ◽  
W. Trent Franks ◽  
Benjamin J. Wylie ◽  
...  
Keyword(s):  
Protein Structure ◽  
Solid State ◽  
Nmr Spectroscopy ◽  
Structure Determination ◽  
Protein Structure Determination ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Triple Resonance ◽  
Angle Spinning

Pulse Shaped Dynamic Nuclear Polarization Under Magic Angle Spinning

2019 ◽  
Author(s):  
ASIF EQUBAL ◽  
Kan Tagami ◽  
Songi Han
Keyword(s):  
Electron Spin ◽  
Lattice Relaxation ◽  
Magic Angle Spinning ◽  
Spin Lattice Relaxation ◽  
Magic Angle ◽  
Total Electron ◽  
Spin Lattice ◽  
Maximum Benefit ◽  
Selective Saturation ◽  
Angle Spinning

In this paper, we report on an entirely novel way of improving the MAS-DNP efficiency by shaped μw pulse train irradiation for fast and broad-banded (FAB) saturation of the electron spin resonance. FAB-DNP achieved with Arbitrary Wave Generated shaped μw pulse trains facilitates effective and selective saturation of a defined fraction of the total electron spins, and provides superior control over the DNP efficiency under MAS. Experimental and quantum-mechanics based numerically simulated results together demonstrate that FAB-DNP significantly outperforms CW-DNP when the EPR-line of PAs is broadened by conformational distribution and exchange coupling. We demonstrate that the maximum benefit of FAB DNP is achieved when the electron spin-lattice relaxation is fast relative to the MAS frequency, i.e. at higher temperatures and/or when employing metals as PAs. Calculations predict that under short T<sub>1e </sub>conditions AWG-DNP can achieve as much as ~4-fold greater enhancement compared to CW-DNP.

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