Solid-state selenium-77 NMR

Demko, Bryan A.; Wasylishen, Roderick E.

doi:10.1016/j.pnmrs.2008.10.002

Cited by 47 publications

(41 citation statements)

References 284 publications

(531 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The relatively narrow signal in the spectrum of LaSe is consistent with its highly symmetric cubic structure, where each Se is surrounded by six La atoms and the isotropic 77 Se chemical shift of ca. 500 p. p.m. is within the range of chemical shifts previously reported for metal selenides 28 . The 77 Se SSNMR spectra of both NbSe 2 and TaSe 2 exhibit broad axially symmetric powder patterns and their isotropic chemical shifts are in a much more positive range than that of LaSe ( Supplementary Fig.…”

Section: Resultssupporting

confidence: 86%

“…The 77 Se SSNMR spectra of both NbSe 2 and TaSe 2 exhibit broad axially symmetric powder patterns and their isotropic chemical shifts are in a much more positive range than that of LaSe ( Supplementary Fig. 13a) or other semiconducting and insulating metal selenides 28 . The 77 Se SSNMR spectrum of commercial NbSe 2 matches that previously reported 29 .…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Unprecedented generation of 3D heterostructures by mechanochemical disassembly and re-ordering of incommensurate metal chalcogenides

et al. 2020

View full text Add to dashboard Cite

Three-dimensional heterostructures are usually created either by assembling twodimensional building blocks into hierarchical architectures or using stepwise chemical processes that sequentially deposit individual monolayers. Both approaches suffer from a number of issues, including lack of suitable precursors, limited reproducibility, and poor scalability of the preparation protocols. Therefore, development of alternative methods that enable preparation of heterostructured materials is desired. We create heterostructures with incommensurate arrangements of well-defined building blocks using a synthetic approach that comprises mechanical disassembly and simultaneous reordering of layered transitionmetal dichalcogenides, MX 2 , and non-layered monochalcogenides, REX, where M = Ta, Nb, RE = Sm, La, and X = S, Se. We show that the discovered solid-state processes are rooted in stochastic mechanochemical transformations directed by electronic interaction between chemically and structurally dissimilar solids toward atomic-scale ordering, and offer an alternative to conventional heterostructuring. Details of composition-structure-properties relationships in the studied materials are also highlighted.

show abstract

Section: Resultssupporting

confidence: 86%

Section: Resultsmentioning

confidence: 99%

Unprecedented generation of 3D heterostructures by mechanochemical disassembly and re-ordering of incommensurate metal chalcogenides

et al. 2020

View full text Add to dashboard Cite

show abstract

“…6 However, isotopic enrichment is necessary for Sec whose resonance widths are reported to be broader in biological systems (see below). 4 The span of selenium chemical shift tensors in diselenide bonds of organic molecules range between 500–900 ppm 7 and the span of the dimeric form of Sec, L-selenocystine, isΩ=601.5 ppm (unpublished measurements). However, the span of the chemical shift tensor of selenylsulfide bonds is expected to be larger.…”

mentioning

confidence: 99%

77Se Enrichment of Proteins Expands the Biological NMR Toolbox

Schaefer¹,

Dong²,

Rubenstein³

et al. 2013

Journal of Molecular Biology

View full text Add to dashboard Cite

Sulfur, a key contributor to biological reactivity, is not amendable to investigations by biological NMR spectroscopy. To utilize selenium as a surrogate, we have developed a generally applicable 77Se isotopic enrichment method for heterologous proteins expressed in E. coli. We demonstrate 77Se NMR spectroscopy of multiple selenocysteine and selenomethionine residues in the sulfhydryl oxidase augmenter of liver regeneration (ALR). The resonances of the active site residues were assigned by comparing the NMR spectra of ALR bound to oxidized and reduced FAD. An additional resonance appears only in the presence of the reducing agent and disappears readily upon exposure to air and subsequent reoxidation of the flavin. Hence, 77Se NMR spectroscopy can be used to report the local electronic environment of reactive and structural sulfur sites, as well as changes taking place in those locations during catalysis.

show abstract

“…It has a wide chemical shift over 6000 ppm, which is beneficial for producing sufficient resolution to separate signals from different chemical sites 36, 37 . However, 77 Se has a low natural abundance ( ca .…”

Section: Introductionmentioning

confidence: 99%

Solid-State 77Se NMR of Organoselenium Compounds through Cross Polarization Magic Angle Spinning (CPMAS) Method

Wei

Han

2017

Sci Rep

View full text Add to dashboard Cite

Characterization of selenium states by 77Se NMR is quite important to provide vital information for mechanism studies in organoselenium-catalyzed reactions. With the development of heterogeneous polymer-supported organoselenium catalysts, the solid state 77Se NMR comes to the spotlight. It is necessary to figure out an advanced protocol that provides good quality spectra within limited time because solid state 77Se NMR measurements are always time consuming due to the long relaxation time and the relatively low sensitivity. Studies on small molecules and several novel polymer-supported organoselenium materials in this article showed that cross polarization (CP) method with the assistance of magic angle spinning (MAS) was more efficient to get high quality spectra than the methods by using single pulse (SP) or high power 1H decoupling (HPHD) combined with MAS. These results lead to a good understanding of the effect of the molecular structure, the heteronuclear coupling, the long-range ordering of the solid (crystal or amorphous), and the symmetry of 77Se on quality of their spectra.

show abstract

Solid-state selenium-77 NMR

Cited by 47 publications

References 284 publications

Unprecedented generation of 3D heterostructures by mechanochemical disassembly and re-ordering of incommensurate metal chalcogenides

Unprecedented generation of 3D heterostructures by mechanochemical disassembly and re-ordering of incommensurate metal chalcogenides

77Se Enrichment of Proteins Expands the Biological NMR Toolbox

Solid-State 77Se NMR of Organoselenium Compounds through Cross Polarization Magic Angle Spinning (CPMAS) Method

Contact Info

Product

Resources

About