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Rehbein SM, Kania MJ, Neufeldt SR. C (sp3)–H Oxidative Addition at Tantalocene Hydrides. Organometallics 2023. [DOI: 10.1021/acs.organomet.2c00672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Affiliation(s)
- Steven M. Rehbein
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Matthew J. Kania
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Sharon R. Neufeldt
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States
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2
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Muthig AMT, Wieland J, Koop S, Lenczyk C, Kerner F, Hupp B, Steffen A. Synthesis and Photophysical Studies of Copper(I) CAAC Half-Sandwich Complexes as a Highly Modifiable Class of Emitters. Inorg Chem 2022; 61:17427-17437. [DOI: 10.1021/acs.inorgchem.2c02073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- André M. T. Muthig
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227Dortmund, Germany
| | - Justin Wieland
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227Dortmund, Germany
| | - Stefan Koop
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227Dortmund, Germany
| | - Carsten Lenczyk
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227Dortmund, Germany
| | - Florian Kerner
- Institute of Inorganic Chemistry, University of Würzburg, Am Hubland, 97074Würzburg, Germany
| | - Benjamin Hupp
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227Dortmund, Germany
| | - Andreas Steffen
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227Dortmund, Germany
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3
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Mary A, Gupta R. Effect of counterion on the reactivity, stability, aromaticity and charge distribution in mono- and polyphosphacyclopentadienide ions – A theoretical investigation. COMPUT THEOR CHEM 2018. [DOI: 10.1016/j.comptc.2018.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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4
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Wong YTA, Landmann J, Finze M, Bryce DL. Dynamic Disorder and Electronic Structures of Electron-Precise Dianionic Diboranes: Insights from Solid-State Multinuclear Magnetic Resonance Spectroscopy. J Am Chem Soc 2017; 139:8200-8211. [PMID: 28548827 DOI: 10.1021/jacs.7b01783] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The J(11B,11B) coupling constants of various salts of the electron-precise hexacyanodiborane(6) dianion, [B2(CN)6]2-, were obtained using 11B double-quantum-filtered (DQF) J-resolved solid-state nuclear magnetic resonance (SSNMR) spectroscopy. Our results show that the magnitude of the DQF J splitting is influenced by both the crystallographic symmetry of the system and the presence of dynamics. The splittings are amplified by a factor of 3 as compared to the corresponding theoretical J coupling constants for cases where (1) there is an absence of dynamics but the boron pairs are crystallographically equivalent or (2) the boron pairs are crystallographically inequivalent but are rendered magnetically equivalent on the time scale of the experiment due to dynamic disorder, which was identified by 11B and 13C SSNMR experiments. Consequently, molecular motions need to be taken into consideration when interpreting the results of DQF J-resolved experiments, and conversely, these experiments may be used to identify dynamic disorder. Variable-temperature NMR data support the notion of three different motional processes with correlation times ranging from 102 to 106 s-1 over the temperature range of 248-306 K. When molecular motion and crystallographic symmetry are both accounted for, the J(11B,11B) coupling constants for various [B2(CN)6]2- salts were measured to range from 29.4 to 35.8 Hz, and their electronic origins were determined using natural localized molecular orbital and natural bond orbital analyses. The coupling constants were found to strongly correlate to the hybridization states of the boron orbitals that form the B-B bonds and to the strength of the B-B bonds. This study provides a novel tool to study dynamics in ordered and disordered solids and provides new perspectives on electron-precise dianionic diboranes featuring two-center-two-electron bonds in the context of related compounds featuring multiply and singly bonded boron spin pairs.
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Affiliation(s)
- Y T Angel Wong
- Department of Chemistry and Biomolecular Sciences & Centre for Catalysis Research and Innovation, University of Ottawa , Ottawa, Ontario, Canada K1N6N5
| | - Johannes Landmann
- Institut für Anorganische Chemie, Institut für nachhaltige Chemie & Katalyse mit Bor (ICB), Julius-Maximilians-Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
| | - Maik Finze
- Institut für Anorganische Chemie, Institut für nachhaltige Chemie & Katalyse mit Bor (ICB), Julius-Maximilians-Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
| | - David L Bryce
- Department of Chemistry and Biomolecular Sciences & Centre for Catalysis Research and Innovation, University of Ottawa , Ottawa, Ontario, Canada K1N6N5
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5
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Lichtenberg C. Aminotroponiminates: Alkali Metal Compounds Reveal Unprecedented Coordination Modes. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00042] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Crispin Lichtenberg
- Institut für Anorganische
Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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6
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Hatua K, Nandi PK. Second hyperpolarizability of multimetallocenes [Cp–Mn–Cp] of Be, Mg and Ca. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2015. [DOI: 10.1142/s0219633615500029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Multimetallocene complexes ( Cp – M n– Cp ) of Be , Mg and Ca have been considered for the theoretical study of static second hyperpolarizability using a number of DFT functionals. Owing to the cooperative effect in bonding, beryllium forms multiberyllocene complexes ( Cp – Be n– Cp ) which have sufficient thermal stability with respect to dissociation into neutral fragments up to n = 10. On the other hand, multimetallocene complexes of Mg and Ca are found to be stable for n ≤ 5 which may be due to the weaker covalent bonding interaction between the larger metal atoms. The rather small variation of linear and cubic polarizabilities of Cp – Be n– Cp complexes beyond n = 5 arises from the rather weaker charge transfer transitions. The difference in NLO property among the investigated metal complexes arises from the extent of charge transfer from the terminal metal atoms and the distance between them. The charge transfer at longer distances in the ground state of Mg and Ca complexes leads to more intense electronic transition — the spectroscopic parameters of which strongly favors the enhancement of second hyperpolarizability.
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Affiliation(s)
- Kaushik Hatua
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
| | - Prasanta K. Nandi
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
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7
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Arias S, Freire F, Quiñoá E, Riguera R. The leading role of cation–π interactions in polymer chemistry: the control of the helical sense in solution. Polym Chem 2015. [DOI: 10.1039/c5py00587f] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cation–π interactions determine the helical sense adopted by a polyphenylacetylene bearing (R)-α-methoxy-α-phenylacetamide as a pendant group (poly-1).
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Affiliation(s)
- Sandra Arias
- Department of Organic Chemistry and Center for Research in Biological Chemistry and Molecular Materials (CIQUS)
- University of Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
| | - Félix Freire
- Department of Organic Chemistry and Center for Research in Biological Chemistry and Molecular Materials (CIQUS)
- University of Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
| | - Emilio Quiñoá
- Department of Organic Chemistry and Center for Research in Biological Chemistry and Molecular Materials (CIQUS)
- University of Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
| | - Ricardo Riguera
- Department of Organic Chemistry and Center for Research in Biological Chemistry and Molecular Materials (CIQUS)
- University of Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
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8
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Hatua K, Nandi PK. Beryllium-cyclobutadiene multidecker inverse sandwiches: electronic structure and second-hyperpolarizability. J Phys Chem A 2013; 117:12581-9. [PMID: 24164393 DOI: 10.1021/jp407563f] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Beryllium forms stable sandwich and inverse sandwich complexes with the cyclobutadiene molecule. Two types of multidecker complexes are designed. Multidecker inverse sandwiches are found to be thermally more stable than the corresponding sandwich complexes. The average distance between two consecutive metals and the two consecutive cyclobutadiene rings increase gradually on increasing size of the chosen inverse sandwich complexes. The density functional theory functionals B3LYP, BHHLYP, BLYP, M06, CAM-B3LYP, and B2PLYP in conjunction with the 6-311++G (d, p) basis set have been employed for calculating the third-order electric response properties of the chosen beryllium-cyclobutadiene complexes and the results obtained for each functional are found to have a consistent trend. Compared to the normal sandwich compounds the second-hyperpolarizability of inverse sandwiches is predicated to be larger, which fairly correlates with the extent of ground-state polarization. The significant enhancement of cubic polarizability of higher-order multidecker inverse sandwiches arises from the strong coupling between the ground and the low lying charge transfer excited states. The rather strong enhancement of second-hyperpolarizability on increasing size of the beryllium-multidecker inverse sandwiches may provide a new route to design efficient nonlinear optical materials.
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Affiliation(s)
- Kaushik Hatua
- Department of Chemistry, Bengal Engineering and Science University , Shibpur, Howrah 711 103, India
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9
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Burgess KM, Perras FA, Lebrun A, Messner-Henning E, Korobkov I, Bryce DL. Sodium-23 Ssolid-Sstate Snuclear Smagnetic Sresonance of Scommercial Ssodium Snaproxen and its Ssolvates. J Pharm Sci 2012; 101:2930-40. [DOI: 10.1002/jps.23196] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 04/10/2012] [Accepted: 04/27/2012] [Indexed: 11/12/2022]
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10
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Wu G, Zhu J. NMR studies of alkali metal ions in organic and biological solids. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2012; 61:1-70. [PMID: 22340207 DOI: 10.1016/j.pnmrs.2011.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2010] [Accepted: 05/31/2011] [Indexed: 05/31/2023]
Affiliation(s)
- Gang Wu
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, Canada.
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11
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12
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Cuny J, Sykina K, Fontaine B, Le Pollès L, Pickard CJ, Gautier R. 95Mo nuclear magnetic resonance parameters of molybdenum hexacarbonyl from density functional theory: appraisal of computational and geometrical parameters. Phys Chem Chem Phys 2011; 13:19471-9. [DOI: 10.1039/c1cp22289a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Mahadevi AS, Sastry GN. A Theoretical Study on Interaction of Cyclopentadienyl Ligand with Alkali and Alkaline Earth Metals. J Phys Chem B 2010; 115:703-10. [DOI: 10.1021/jp109749a] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- A. Subha Mahadevi
- Molecular Modeling Group, Organic Chemical Sciences, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, AP, India
| | - G. Narahari Sastry
- Molecular Modeling Group, Organic Chemical Sciences, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, AP, India
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14
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Rossini AJ, Hung I, Johnson SA, Slebodnick C, Mensch M, Deck PA, Schurko RW. Solid-State 91Zr NMR Spectroscopy Studies of Zirconocene Olefin Polymerization Catalyst Precursors. J Am Chem Soc 2010; 132:18301-17. [DOI: 10.1021/ja107749b] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Aaron J. Rossini
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4, and Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0121, United States
| | - Ivan Hung
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4, and Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0121, United States
| | - Samuel A. Johnson
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4, and Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0121, United States
| | - Carla Slebodnick
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4, and Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0121, United States
| | - Mike Mensch
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4, and Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0121, United States
| | - Paul A. Deck
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4, and Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0121, United States
| | - Robert W. Schurko
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4, and Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0121, United States
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15
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McMillen CH, Gren CK, Hanusa TP, Rheingold AL. A tetrameric allyl complex of sodium, and computational modeling of the 23Na–allyl chemical shift. Inorganica Chim Acta 2010. [DOI: 10.1016/j.ica.2010.07.079] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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16
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Gomes CSB, Suresh D, Gomes PT, Veiros LF, Duarte MT, Nunes TG, Oliveira MC. Sodium complexes containing 2-iminopyrrolyl ligands: the influence of steric hindrance in the formation of coordination polymers. Dalton Trans 2010; 39:736-48. [PMID: 20066219 DOI: 10.1039/b905948b] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Clara S B Gomes
- Centro de Química Estrutural, Departamento de Engenharia Química e Biológica, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
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17
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Pathmalingam T, Habib F, Widdifield CM, Loiseau F, Burchell TJ, Gorelsky SI, Beauchemin AM, Bryce DL, Murugesu M. Combining oximes with azides to create a novel 1-D [NaCoIII2] system: synthesis, structure and solid-state NMR. Dalton Trans 2010; 39:1504-10. [DOI: 10.1039/b918082f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Wong A, Kotch FW, Kwan ICM, Davis JT, Wu G. Probing the Na+ binding site in a calix[4]arene–guanosine conjugate dimer by solid-state 23Na NMR and quantum chemical calculation. Chem Commun (Camb) 2009:2154-6. [DOI: 10.1039/b900442d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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19
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Cuny J, Messaoudi S, Alonzo V, Furet E, Halet JF, Le Fur E, Ashbrook SE, Pickard CJ, Gautier R, Le Polles L. DFT calculations of quadrupolar solid-state NMR properties: Some examples in solid-state inorganic chemistry. J Comput Chem 2008; 29:2279-87. [DOI: 10.1002/jcc.21028] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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20
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Wu G, Terskikh V. A Multinuclear Solid-State NMR Study of Alkali Metal Ions in Tetraphenylborate Salts, M[BPh4] (M = Na, K, Rb and Cs): What Is the NMR Signature of Cation−π Interactions? J Phys Chem A 2008; 112:10359-64. [DOI: 10.1021/jp8064739] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Gang Wu
- Department of Chemistry, Queen’s University, 90 Bader Lane, Kingston, Ontario, Canada K7L 3N6, and Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, Canada K1A 0R6
| | - Victor Terskikh
- Department of Chemistry, Queen’s University, 90 Bader Lane, Kingston, Ontario, Canada K7L 3N6, and Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, Canada K1A 0R6
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21
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Ida R, Wu G. Direct NMR detection of alkali metal ions bound to G-quadruplex DNA. J Am Chem Soc 2008; 130:3590-602. [PMID: 18293981 DOI: 10.1021/ja709975z] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe a general multinuclear (1H, 23Na, 87Rb) NMR approach for direct detection of alkali metal ions bound to G-quadruplex DNA. This study is motivated by our recent discovery that alkali metal ions (Na+, K+, Rb+) tightly bound to G-quadruplex DNA are actually "NMR visible" in solution (Wong, A.; Ida, R.; Wu, G. Biochem. Biophys. Res. Commun. 2005, 337, 363). Here solution and solid-state NMR methods are developed for studying ion binding to the classic G-quadruplex structures formed by three DNA oligomers: d(TG4T), d(G4T3G4), and d(G4T4G4). The present study yields the following major findings. (1) Alkali metal ions tightly bound to G-quadruplex DNA can be directly observed by NMR in solution. (2) Competitive ion binding to the G-quadruplex channel site can be directly monitored by simultaneous NMR detection of the two competing ions. (3) Na+ ions are found to locate in the diagonal T4 loop region of the G-quadruplex formed by two strands of d(G4T4G4). This is the first time that direct NMR evidence has been found for alkali metal ion binding to the diagonal T4 loop in solution. We propose that the loop Na+ ion is located above the terminal G-quartet, coordinating to four guanine O6 atoms from the terminal G-quartet and one O2 atom from a loop thymine base and one water molecule. This Na+ ion coordination is supported by quantum chemical calculations on 23Na chemical shifts. Variable-temperature 23Na NMR results have revealed that the channel and loop Na+ ions in d(G4T4G4) exhibit very different ion mobilities. The loop Na+ ions have a residence lifetime of 220 micros at 15 degrees C, whereas the residence lifetime of Na+ ions residing inside the G-quadruplex channel is 2 orders of magnitude longer. (4) We have found direct 23Na NMR evidence that mixed K+ and Na+ ions occupy the d(G4T4G4) G-quadruplex channel when both Na+ and K+ ions are present in solution. (5) The high spectral resolution observed in this study is unprecedented in solution 23Na NMR studies of biological macromolecules. Our results strongly suggest that multinuclear NMR is a viable technique for studying ion binding to G-quadruplex DNA.
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Affiliation(s)
- Ramsey Ida
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, Canada K7L 3N6
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22
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Widdifield CM, Tang JA, Macdonald CLB, Schurko RW. Investigation of structure and dynamics in the sodium metallocenes CpNa and CpNa·THF via solid-state NMR, X-ray diffraction and computational modelling. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2007; 45 Suppl 1:S116-S128. [PMID: 18172908 DOI: 10.1002/mrc.2124] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Solid-state (23) Na NMR spectra of two organometallic complexes, cyclopentadienylsodium (CpNa) and the tetrahydrofuran (THF) solvate of CpNa (CpNa·THF), are presented. Analytical simulations of experimental spectra and calculated (23) Na electric-field gradient (EFG) tensors confirm that both complexes are present in microcrystalline samples of CpNa recrystallized from THF. For the solvate, (23) Na NMR experiments at 9.4 T and 11.7 T elucidate sodium chemical shielding (CS) tensor parameters, and establish that the EFG and CS tensor frames are non-coincident. Single-crystal X-ray diffraction (XRD) experiments are used to determine the crystal structure of CpNa·THF: Cmca (a = 9.3242(15) Å, b = 20.611(3) Å, c = 9.8236(14) Å, α = β = γ = 90° , V = 1887.9(5)Å(3) , Z = 8). For CpNa, (23) Na NMR data acquired at multiple field strengths establish sodium CS tensor parameters more precisely than in previous reports. Variable-temperature (VT) powder XRD (pXRD) experiments determine the temperature dependence of the CpNa unit cell parameters. The combination of (23) Na quadrupolar NMR parameters, pXRD data and calculations of (23) Na EFG tensors is used to examine various models of dynamic motion in the solid state. It is proposed that the sodium atom in CpNa undergoes an anisotropic, temperature-dependent, low frequency motion within the ab crystallographic plane, in contrast with previous models.
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Affiliation(s)
- Cory M Widdifield
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4
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23
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Ooms KJ, Terskikh VV, Wasylishen RE. Ultrahigh-Field Solid-State 59Co NMR Studies of Co(C2B9H11)2- and Co(C5H5)2+ Salts. J Am Chem Soc 2007; 129:6704-5. [PMID: 17477532 DOI: 10.1021/ja0710095] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kristopher J Ooms
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
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24
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Bryce DL, Adiga S, Elliott EK, Gokel GW. Solid-State 23Na NMR Study of Sodium Lariat Ether Receptors Exhibiting Cation−π Interactions. J Phys Chem A 2006; 110:13568-77. [PMID: 17165884 DOI: 10.1021/jp065171q] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Noncovalent cation-pi interactions are important in a variety of supramolecular and biochemical systems. We present a 23Na solid-state nuclear magnetic resonance (SSNMR) study of two sodium lariat ether complexes, 1 and 2, in which a sodium cation interacts with an indolyl group that models the side chain of tryptophan. Sodium-23 SSNMR spectra of magic-angle spinning (MAS) and stationary powdered samples have been acquired at three magnetic field strengths (9.4, 11.75, 21.1 T) and analyzed to provide key information on the sodium electric field gradient and chemical shift (CS) tensors which are representative of the cation-pi binding environment. Triple-quantum MAS NMR spectra acquired at 21.1 T clearly reveal two crystallographically distinct sites in both 1 and 2. The quadrupolar coupling constants, CQ(23Na), range from 2.92 +/- 0.05 MHz for site A of 1 to 3.33 +/- 0.05 MHz for site B of 2; these values are somewhat larger than those reported previously by Wong et al. (Wong, A.; Whitehead, R. D.; Gan, Z.; Wu, G. J. Phys. Chem. A 2004, 108, 10551) for NaBPh4, but very similar to the values obtained for sodium metallocenes by Willans and Schurko (Willans, M. J.; Schurko, R. W. J. Phys. Chem. B 2003, 107, 5144). We conclude from the 21.1 T data that the spans of the sodium CS tensors are less than 20 ppm for 1 and 2 and that the largest components of the EFG and CS tensors are non-coincident. Quantum chemical calculations of the NMR parameters substantiate the experimental findings and provide additional insight into the dependence of CQ(23Na) on the proximity of the indole ring to Na+. Taken together, this work has provided novel information on the NMR interaction tensors characteristic of a sodium cation interacting with a biologically important arene.
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Affiliation(s)
- David L Bryce
- Department of Chemistry and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
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25
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Gee BA. Vanadium-51 solid-state NMR electric field gradient tensors: a DFT-embedded ion and isolated cluster study of crystalline vanadium oxides. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2006; 30:171-81. [PMID: 17023147 DOI: 10.1016/j.ssnmr.2006.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2006] [Revised: 08/22/2006] [Accepted: 08/31/2006] [Indexed: 05/12/2023]
Abstract
Density functional theory (DFT) calculations (6-311+G(2d,p)/B3LYP level of theory) of (51)V electric field gradient (EFG) tensor elements are performed for embedded and isolated cluster models of orthovanadates. The structural models used to calculate the EFGs of (51)V are (I) an isolated H(4)VO(4)(+) cluster, (II) an isolated H(n)VO(4)(n-3) cluster (n=number of next-neighbor cations) (III) an isolated orthovanadate anion, VO(4)(-x), and (IV) a VO(4)(-x) ion embedded in a finite point-charge array whose electrostatic potential, at the embedded ion, is equivalent to that of the infinite lattice. For models III and IV, a charge x is assigned estimating the covalence of the system. Models III and IV provide results in good agreement with the experiment. Calculations, employing the embedded and isolated VO(4)(-x) models, are used to discuss site assignments for AlVO(4). Correlations between quadrupole coupling parameters and deviations of the orthovanadate structure from ideal tetrahedral symmetry are shown.
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Affiliation(s)
- Becky A Gee
- Department of Chemistry and Biochemistry, 1 University Plaza, Long Island University, Brooklyn Campus, Brooklyn, NY 11201, USA.
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Rossini AJ, Schurko RW. Experimental and Theoretical Studies of 45Sc NMR Interactions in Solids. J Am Chem Soc 2006; 128:10391-402. [PMID: 16895404 DOI: 10.1021/ja060477w] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Solid-state 45Sc NMR spectroscopy, ab initio calculations, and X-ray crystallography are applied to examine the relationships between 45Sc NMR interactions and molecular structure and symmetry. Solid-state 45Sc (I = 7/2) magic-angle spinning (MAS) and static NMR spectra of powdered samples of Sc(acac)3, Sc(TMHD)3, Sc(NO3)3.5H2O, Sc(OAc)3, ScCl3.6H2O, ScCl3.3THF, and ScCp3 have been acquired. These systems provide a variety of scandium coordination environments yielding an array of distinct 45Sc chemical shielding (CS) and electric field gradient (EFG) tensor parameters. Acquisition of spectra at two distinct magnetic fields allows for the first observations of scandium chemical shielding anisotropy (CSA). 45Sc quadrupolar coupling constants (CQ) range from 3.9 to 13.1 MHz and correlate directly with the symmetry of the scandium coordination environment. Single-crystal X-ray structures were determined for Sc(TMHD)3, ScCl3.6H2O, and Sc(NO3)3.5H2O to establish the hitherto unknown scandium coordination environments. A comprehensive series of ab initio calculations of EFG and CS tensor parameters are in excellent agreement with the observed parameters. Theoretically determined orientations of the NMR interaction tensors allow for correlations between NMR tensor characteristics and scandium environments. Solid-state 45Sc, 13C, and 19F NMR experiments are also applied to characterize the structures of the microcrystalline Lewis acid catalyst Sc(OTf)3 (for which the crystal structure is unknown) and a noncrystalline, microencapsulated, polystyrene-supported form of the compound.
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Affiliation(s)
- Aaron J Rossini
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4
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Lo AYH, Bitterwolf TE, Macdonald CLB, Schurko RW. Solid-State 93Nb and 13C NMR Investigations of Half-Sandwich Niobium(I) and Niobium(V) Cyclopentadienyl Complexes. J Phys Chem A 2005; 109:7073-87. [PMID: 16834070 DOI: 10.1021/jp0521499] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Solid-state 93Nb and 13C NMR experiments, in combination with theoretical calculations of NMR tensors, and single-crystal and powder X-ray diffraction experiments, are applied for the comprehensive characterization of structure and dynamics in a series of organometallic niobium complexes. Half-sandwich niobium metallocenes of the forms Cp'Nb(I)(CO)4 and CpNb(V)Cl4 are investigated, where Cp = C5H5- and Cp' = C5H4R- with R = COMe, CO2Me, CO2Et, and COCH2Ph. Anisotropic quadrupolar and chemical shielding (CS) parameters are extracted from 93Nb MAS and static NMR spectra for seven different complexes. It is demonstrated that 93Nb NMR parameters are sensitive to changes in temperature and Cp' ring substitution in the Cp'Nb(I)(CO)4 complexes. There are dramatic differences in the 93Nb quadrupolar coupling constants (C(Q)) between the Nb(I) and Nb(V) complexes, with C(Q) between 1.0 and 12.0 MHz for Cp'Nb(CO)4 and C(Q) = 54.5 MHz for CpNbCl4. The quadrupolar Carr-Purcell Meiboom-Gill (QCPMG) pulse sequence is applied to rapidly acquire, in a piecewise fashion, a high signal-to-noise ultra-wide-line 93Nb NMR spectrum of CpNbCl4, which has a breadth of ca. 400 kHz. Solid-state 93Nb and 13C NMR spectra and powder XRD data are used to identify a new metallocene adduct coordinated at the axial position of the metal site by a THF molecule: CpNb(V)Cl4.THF. 13C MAS and CP/MAS NMR experiments are used to assess the purity of samples, as well as for measuring carbon CS tensors and the rare instance of one-bond 93Nb, 13C J-coupling, 1J(93Nb,13C). Theoretically calculated CS and electric field gradient (EFG) tensors are utilized to determine relationships between tensor orientations, the principal components, and molecular structures.
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Affiliation(s)
- Andy Y H Lo
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4
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Widdifield CM, Schurko RW. A Solid-State 39K and 13C NMR Study of Polymeric Potassium Metallocenes. J Phys Chem A 2005; 109:6865-76. [PMID: 16834043 DOI: 10.1021/jp058059l] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The quadrupolar Carr-Purcell Meiboom-Gill (QCPMG) and double frequency sweep (DFS)/QCPMG pulse sequences are applied in order to acquire the first solid-state 39K NMR spectra of organometallic complexes, the polymeric main group metallocenes cyclopentadienyl potassium (CpK) and pentamethylcyclopentadienyl potassium (Cp*K). Piecewise QCPMG NMR techniques are used to acquire a high S/N 39K spectrum of the broad central transition of Cp*K, which is ca. 200 kHz in breadth. Analytical and numerical simulations indicate that there is a significant quadrupolar interaction present at both potassium nuclei (C(Q)(39K) = 2.55(6)/2.67(8) MHz and 4.69(8) MHz for CpK (static/MAS) and Cp*K, respectively). Experimental quadrupolar asymmetry parameters suggest that both structures are bent about the potassium atoms (eta(Q)(39K) = 0.28(3)/0.29(3) for CpK (static/MAS) and eta(Q)(39K) = 0.30(3) for Cp*K). Variable-temperature (VT) 39K NMR experiments on CpK elucidate temperature-dependent changes in quadrupolar parameters which can be rationalized in terms of alterations of bond distances and angles with temperature. 13C CP/MAS NMR experiments are conducted upon both samples to quantify the carbon chemical shielding anisotropy (CSA) at the Cp' ring carbon atoms. Ab initio carbon CSA and 39K electric-field gradient (EFG) and CSA calculations are conducted and discussed for the CpK complex, in order to correlate the experimental NMR parameters with molecular structure in CpK and Cp*K. 39K DFS/QCPMG and 13C CP/MAS experiments prove invaluable for probing molecular structure, temperature-dependent structural changes, and the presence of impurities in these systems.
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Affiliation(s)
- Cory M Widdifield
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4
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Wong A, Whitehead RD, Gan Z, Wu G. A Solid-State NMR and Computational Study of Sodium and Potassium Tetraphenylborates: 23Na and 39K NMR Signatures for Systems Containing Cation−π Interactions. J Phys Chem A 2004. [DOI: 10.1021/jp0468051] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alan Wong
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6, Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, Canada K7K 7B4, and Center of Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310
| | - Robert D. Whitehead
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6, Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, Canada K7K 7B4, and Center of Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310
| | - Zhehong Gan
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6, Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, Canada K7K 7B4, and Center of Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310
| | - Gang Wu
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6, Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, Canada K7K 7B4, and Center of Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310
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Schurko RW, Willans MJ, Skadtchenko B, Antonelli DM. Solid-state 23Na and 13C NMR characterization of Na3C60. J SOLID STATE CHEM 2004. [DOI: 10.1016/j.jssc.2004.02.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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