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Pálla T, Herbath L, Mazák K, Mirzahosseini A, Noszál B. Selenate-An internal chemical shift standard for aqueous 77 Se NMR spectroscopy. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2022; 60:148-156. [PMID: 34273131 DOI: 10.1002/mrc.5196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
The 77 Se NMR spectra of selenate were studied under various circumstances, such as concentration, pH, temperature, ionic strength, and D2 O:H2 O ratio, in order to examine its potential as a water-soluble internal chemical shift standard. The performance of selenate as a chemical shift reference and that of other attempted ones from the literature (dimethyl selenide, tetramethylsilane/TMS, and 3-(trimethylsilyl)propane-1-sulfonate/DSS) was also explored. The uncertainty in the resulting chemical shift relative to the effective spectral width is comparable to that of DSS. Compared to the currently prevalent water-soluble external chemical shift reference, selenic acid solution, the properties of internal selenate are much more favorable in terms of ease of use. We have also demonstrated that selenate can be used in reducing media, which is inevitable for the analysis of selenol compounds. Thus, it can be stated that sodium selenate is a robust internal chemical shift reference in aqueous media for 77 Se NMR measurements; the chemical shift of this reference in a solution containing 5 V/V% D2 O at 25°C and 0.15 mol·dm-3 ionic strength is 1048.65 ppm relative to 60 V/V% dimethyl selenide in CDCl3 and 1046.40 ppm relative to the 1 H signal of 0.03 V/V% TMS in CDCl3 . In summary, a water-soluble, selenium-containing internal chemical shift reference compound was introduced for 77 Se NMR measurements for the first time in the literature, and with the aforementioned results all previous 77 Se measurements can be converted to a unified scale defined by the International Union of Pure and Applied Chemistry.
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Affiliation(s)
- Tamás Pálla
- Department of Pharmaceutical Chemistry, Semmelweis University, Budapest, Hungary
| | - Laura Herbath
- Department of Pharmaceutical Chemistry, Semmelweis University, Budapest, Hungary
| | - Károly Mazák
- Department of Pharmaceutical Chemistry, Semmelweis University, Budapest, Hungary
| | - Arash Mirzahosseini
- Department of Pharmaceutical Chemistry, Semmelweis University, Budapest, Hungary
| | - Béla Noszál
- Department of Pharmaceutical Chemistry, Semmelweis University, Budapest, Hungary
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Sutrisno A, Lo AY, Tang JA, Dutton JL, Farrar GJ, Ragogna PJ, Zheng S, Autschbach J, Schurko RW. Experimental and theoretical investigations of selenium nuclear magnetic shielding tensors in Se–N heterocycles. CAN J CHEM 2009. [DOI: 10.1139/v09-100] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A preliminary study involving solid-state 77Se NMR spectroscopy and first principles calculations of 77Se NMR parameters in Se–N heterocycles is reported. 77Se CP/MAS NMR spectra of the ring systems reveal expansive selenium chemical shift (CS) tensors, which are extremely sensitive to molecular geometry, symmetry, ligand substitution, and intermolecular contacts. For systems with known crystal structures, hybrid density functional theory (DFT) calculations of selenium nuclear magnetic shielding (NMS) tensors were carried out, and tensor orientations in the molecular frames examined. Additional DFT calculations of selenium NMS tensors are presented, along with a detailed analysis of pairs of occupied and virtual molecular orbitals that give rise to the Se NMS tensors. A new naturalized local molecular orbital (NLMO) analysis under the same DFT framework is also discussed. Collectively, the NMR data and first principles calculations provide understanding of the influences of electronic structure, bonding, and intermolecular interactions on the selenium NMS tensors, allowing for (i) prediction of unknown molecular structures and (ii) insight into the positions of the stereochemically active selenium lone pairs.
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Affiliation(s)
- Andre Sutrisno
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
- Department of Chemistry, The University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Chemistry, The State University of New York, Buffalo, NY 14260-3000, USA
| | - Andy Y.H. Lo
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
- Department of Chemistry, The University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Chemistry, The State University of New York, Buffalo, NY 14260-3000, USA
| | - Joel A. Tang
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
- Department of Chemistry, The University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Chemistry, The State University of New York, Buffalo, NY 14260-3000, USA
| | - Jason L. Dutton
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
- Department of Chemistry, The University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Chemistry, The State University of New York, Buffalo, NY 14260-3000, USA
| | - Gregg J. Farrar
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
- Department of Chemistry, The University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Chemistry, The State University of New York, Buffalo, NY 14260-3000, USA
| | - Paul J. Ragogna
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
- Department of Chemistry, The University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Chemistry, The State University of New York, Buffalo, NY 14260-3000, USA
| | - Shaohui Zheng
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
- Department of Chemistry, The University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Chemistry, The State University of New York, Buffalo, NY 14260-3000, USA
| | - Jochen Autschbach
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
- Department of Chemistry, The University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Chemistry, The State University of New York, Buffalo, NY 14260-3000, USA
| | - Robert W. Schurko
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
- Department of Chemistry, The University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Chemistry, The State University of New York, Buffalo, NY 14260-3000, USA
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Kemp TF, Wong A, Smith ME, Bishop PT, Carthey N. A natural abundance (77)Se solid-state NMR study of inorganic compounds. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2008; 34:224-227. [PMID: 19064315 DOI: 10.1016/j.ssnmr.2008.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2008] [Revised: 10/04/2008] [Accepted: 10/22/2008] [Indexed: 05/27/2023]
Abstract
Various inorganic selenium-based compounds were analysed by (77)Se solid-state NMR, and a distinct difference in chemical shift ranges for compounds where selenium is present as selenide (Se(2-)) ionically and covalently bonded systems was observed. The selenides exhibit a shift range of approximately -700 to -100ppm, as opposed to 700 to 1600ppm for the compounds where there tends to be more direct covalent bonding to the selenium. The anisotropic hyperfine shift observed in NbSe(2) is shown to be axially symmetric, where the H(11) component is found to be normal to the Se3-trigonal plane.
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Affiliation(s)
- T F Kemp
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
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Ratcliffe CI, Yu K, Ripmeester JA, Badruz Zaman M, Badarau C, Singh S. Solid state NMR studies of photoluminescent cadmium chalcogenide nanoparticles. Phys Chem Chem Phys 2006; 8:3510-9. [PMID: 16871340 DOI: 10.1039/b606507b] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Solid state (113)Cd, (77)Se, (13)C and (31)P NMR have been used to study a number of Cd chalcogenide nanoparticles synthesized in tri-n-octyl-phosphine (TOP) with different compositions and architectures. The pure CdSe and CdTe nanoparticles show a dramatic, size-sensitive broadening of the (113)Cd NMR line, which can be explained in terms of a chemical shift distribution arising from multiple Cd environments. From (13)C NMR, it has been discovered that TOP, or its derivatives such as TOPO (trioctylphosphine oxide), is rapidly moving about the surface of the nanoparticles, indicating that it is relatively weakly bound as compared to other materials used as surface ligands, such as hexadecylamine. (31)P NMR of the nanoparticles shows at least five species arising from coordination of the ligands to different surface sites. (113)Cd NMR of CdSeTe alloy and layered nanoparticles has provided crucial information which, in conjunction with results from other techniques (especially optical characterization), has made it possible to develop a detailed picture of the composition and structure of these materials: (i) a true CdSeTe homogeneous alloy nanoparticle, (ii) a nanoparticle segregated into an alloy core region rich in Te, with a CdSeTe (close to 1 : 1 Se : Te) alloy shell and (iii) a CdSe/CdTe/CdSe layered nanoparticle in which the CdTe layer contains a small amount of Se and which forms a Quantum Dot Quantum Well (QDQW) system. The results demonstrate that solid state NMR is a vital tool in the arsenal of characterisation techniques available for nanomaterials.
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Affiliation(s)
- Christopher I Ratcliffe
- Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario, Canada K1A 0R6.
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