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Rinald A, Terskikh V, Schatte G, Wu G. A combined solid-state 17O NMR, crystallographic, and computational study of oxiranes. CAN J CHEM 2020. [DOI: 10.1139/cjc-2020-0114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We report the synthesis and solid-state 17O NMR characterization of three 17O-labeled oxiranes: (2S*,3S*)-2,3-bis(4-nitrophenyl)-[17O]oxirane, (2S*,3R*)-2,3-bis(4-nitrophenyl)-[17O]oxirane, and 2,2,3-triphenyl-[17O]oxirane. In addition, we have determined the crystal structure of (2S*,3R*)-2,3-bis(4-nitrophenyl)oxirane by X-ray crystallography. When the experimentally determined 17O NMR tensors for oxiranes (where the C–O–C bond angle is about 60°) are compared with those for dimethyl ether (where the C–O–C bond angle is 113°) and other R–O–R′ functional groups, we found that the highly constrained geometry of oxiranes results in distinct tensor orientations in the molecular frame of reference. The experimental results are complemented by quantum chemical computations. This study represents the first time that 17O chemical shift and quadrupole coupling tensors are simultaneously determined for oxirane compounds.
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Affiliation(s)
- Andrew Rinald
- Department of Chemistry, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - Victor Terskikh
- Department of Chemistry, Queen’s University, Kingston, ON K7L 3N6, Canada
- Department of Chemistry, University of Ottawa, Ottawa, ON K1A 0R6, Canada
| | - Gabriele Schatte
- Department of Chemistry, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - Gang Wu
- Department of Chemistry, Queen’s University, Kingston, ON K7L 3N6, Canada
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Wu G. 17O NMR studies of organic and biological molecules in aqueous solution and in the solid state. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2019; 114-115:135-191. [PMID: 31779879 DOI: 10.1016/j.pnmrs.2019.06.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/11/2019] [Accepted: 06/11/2019] [Indexed: 06/10/2023]
Abstract
This review describes the latest developments in the field of 17O NMR spectroscopy of organic and biological molecules both in aqueous solution and in the solid state. In the first part of the review, a general theoretical description of the nuclear quadrupole relaxation process in isotropic liquids is presented at a mathematical level suitable for non-specialists. In addition to the first-order quadrupole interaction, the theory also includes additional relaxation mechanisms such as the second-order quadrupole interaction and its cross correlation with shielding anisotropy. This complete theoretical treatment allows one to assess the transverse relaxation rate (thus the line width) of NMR signals from half-integer quadrupolar nuclei in solution over the entire range of motion. On the basis of this theoretical framework, we discuss general features of quadrupole-central-transition (QCT) NMR, which is a particularly powerful method of studying biomolecules in the slow motion regime. Then we review recent advances in 17O QCT NMR studies of biological macromolecules in aqueous solution. The second part of the review is concerned with solid-state 17O NMR studies of organic and biological molecules. As a sequel to the previous review on the same subject [G. Wu, Prog. Nucl. Magn. Reson. Spectrosc. 52 (2008) 118-169], the current review provides a complete coverage of the literature published since 2008 in this area.
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Affiliation(s)
- Gang Wu
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada.
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Ehinger C, Gordon CP, Copéret C. Oxygen transfer in electrophilic epoxidation probed by 17O NMR: differentiating between oxidants and role of spectator metal oxo. Chem Sci 2018; 10:1786-1795. [PMID: 30842846 PMCID: PMC6369410 DOI: 10.1039/c8sc04868a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 11/30/2018] [Indexed: 11/21/2022] Open
Abstract
Peroxide compounds are used both in laboratory and industrial processes for the electrophilic epoxidation of olefins. Using NMR-spectroscopy, we investigate why certain peroxides engage in this type of reaction while others require activation by metal catalysts, e.g. methyltrioxorhenium (MTO). More precisely, an analysis of 17O NMR chemical shift and quadrupolar coupling parameters provides insights into the relative energy of specific frontier molecular orbitals relevant for reactivity. For organic peroxides or H2O2 a large deshielding is indicative of an energetically high-lying lone-pair on oxygen in combination with a low-lying σ*(O-O) orbital. This feature is particularly pronounced in species that engage in electrophilic epoxidation, such as peracids or dimethyldioxirane (DMDO), and much less pronounced in unreactive peroxides such as H2O2 and ROOH, which can however be activated by transition-metal catalysts. In fact, for the proposed active peroxo species in MTO-catalyzed electrophilic epoxidation with H2O2 an analysis of the 17O NMR chemical shift highlights specific π- and δ-type orbital interactions between the so-called metal spectator oxo and the peroxo moieties that raise the energy of the high-lying lone-pair on oxygen, thus increasing the reactivity of the peroxo species.
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Affiliation(s)
- Christian Ehinger
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir Prelog Weg 1-5 , 8093 , Zürich , Switzerland .
| | - Christopher P Gordon
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir Prelog Weg 1-5 , 8093 , Zürich , Switzerland .
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir Prelog Weg 1-5 , 8093 , Zürich , Switzerland .
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Zhang S, Nava MJ, Chow GK, Lopez N, Wu G, Britt DR, Nocera DG, Cummins CC. On the incompatibility of lithium-O 2 battery technology with CO 2. Chem Sci 2017; 8:6117-6122. [PMID: 28989641 PMCID: PMC5625616 DOI: 10.1039/c7sc01230f] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 06/19/2017] [Indexed: 12/22/2022] Open
Abstract
When solubilized in a hexacarboxamide cryptand anion receptor, the peroxide dianion reacts rapidly with CO2 in polar aprotic organic media to produce hydroperoxycarbonate (HOOCO2-) and peroxydicarbonate (-O2COOCO2-). Peroxydicarbonate is subject to thermal fragmentation into two equivalents of the highly reactive carbonate radical anion, which promotes hydrogen atom abstraction reactions responsible for the oxidative degradation of organic solvents. The activation and conversion of the peroxide dianion by CO2 is general. Exposure of solid lithium peroxide (Li2O2) to CO2 in polar aprotic organic media results in aggressive oxidation. These findings indicate that CO2 must not be introduced in conditions relevant to typical lithium-O2 cell configurations, as production of HOOCO2- and -O2COOCO2- during lithium-O2 cell cycling will lead to cell degradation via oxidation of organic electrolytes and other vulnerable cell components.
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Affiliation(s)
- Shiyu Zhang
- Department of Chemistry , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139-4307 , USA . ; Tel: +1 617 253 5332
| | - Matthew J Nava
- Department of Chemistry , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139-4307 , USA . ; Tel: +1 617 253 5332
| | - Gary K Chow
- Department of Chemistry , University of California , Davis, One Shields Avenue , Davis , CA 95616 , USA
| | - Nazario Lopez
- Department of Chemistry , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139-4307 , USA . ; Tel: +1 617 253 5332
| | - Gang Wu
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario K7L3N6 , Canada
| | - David R Britt
- Department of Chemistry , University of California , Davis, One Shields Avenue , Davis , CA 95616 , USA
| | - Daniel G Nocera
- Department of Chemistry and Chemical Biology , Harvard University , 12 Oxford Street , Cambridge , MA 02138 , USA
| | - Christopher C Cummins
- Department of Chemistry , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139-4307 , USA . ; Tel: +1 617 253 5332
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Gao Y, Dai Y, Wu G. Solid-State 15N and 17O NMR Studies of S-Nitrosothiols. J Phys Chem B 2017; 121:7311-7317. [DOI: 10.1021/acs.jpcb.7b05685] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Yin Gao
- The
College of Life Sciences, Jilin University, 2699 Qianjin Street, Changchun 130012, China
- Department
of Chemistry, Queen’s University, 90 Bader Lane, Kingston, Ontario K7L
3N6, Canada
| | - Yizhe Dai
- Department
of Chemistry, Queen’s University, 90 Bader Lane, Kingston, Ontario K7L
3N6, Canada
| | - Gang Wu
- Department
of Chemistry, Queen’s University, 90 Bader Lane, Kingston, Ontario K7L
3N6, Canada
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Wu G. Solid-State ¹⁷O NMR studies of organic and biological molecules: Recent advances and future directions. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2016; 73:1-14. [PMID: 26651417 DOI: 10.1016/j.ssnmr.2015.11.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 11/20/2015] [Accepted: 11/24/2015] [Indexed: 05/04/2023]
Abstract
This Trends article highlights the recent advances published between 2012 and 2015 in solid-state (17)O NMR for organic and biological molecules. New developments in the following areas are described: (1) new oxygen-containing functional groups, (2) metal organic frameworks, (3) pharmaceuticals, (4) probing molecular motion in organic solids, (5) dynamic nuclear polarization, and (6) paramagnetic coordination compounds. For each of these areas, the author offers his personal views on important problems to be solved and possible future directions.
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Affiliation(s)
- Gang Wu
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, Canada K7L 3N6
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