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Xu Y, Chen J, Aydt AP, Zhang L, Sergeyev I, Keeler EG, Choi B, He S, Reichman DR, Friesner RA, Nuckolls C, Steigerwald ML, Roy X, McDermott AE. Electron and Spin Delocalization in [Co 6 Se 8 (PEt 3 ) 6 ] 0/+1 Superatoms. Chemphyschem 2024; 25:e202300064. [PMID: 38057144 DOI: 10.1002/cphc.202300064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 11/01/2023] [Indexed: 12/08/2023]
Abstract
Molecular clusters can function as nanoscale atoms/superatoms, assembling into superatomic solids, a new class of solid-state materials with designable properties through modifications on superatoms. To explore possibilities on diversifying building blocks, here we thoroughly studied one representative superatom, Co6 Se8 (PEt3 )6 . We probed its structural, electronic, and magnetic properties and revealed its detailed electronic structure as valence electrons delocalize over inorganic [Co6 Se8 ] core while ligands function as an insulated shell. 59 Co SSNMR measurements on the core and 31 P, 13 C on the ligands show that the neutral Co6 Se8 (PEt3 )6 is diamagnetic and symmetric, with all ligands magnetically equivalent. Quantum computations cross-validate NMR results and reveal degenerate delocalized HOMO orbitals, indicating aromaticity. Ligand substitution keeps the inorganic core nearly intact. After losing one electron, the unpaired electron in [Co6 Se8 (PEt3 )6 ]+1 is delocalized, causing paramagnetism and a delocalized electron spin. Notably, this feature of electron/spin delocalization over a large cluster is attractive for special single-electron devices.
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Affiliation(s)
- Yunyao Xu
- Department of Chemistry, Columbia University New York, New York, 10027, USA
| | - Jia Chen
- Department of Chemistry, Columbia University New York, New York, 10027, USA
| | - Alexander P Aydt
- Department of Chemistry, Columbia University New York, New York, 10027, USA
| | - Lichirui Zhang
- Department of Chemistry, Columbia University New York, New York, 10027, USA
| | - Ivan Sergeyev
- Department of Chemistry, Columbia University New York, New York, 10027, USA
| | - Eric G Keeler
- Department of Chemistry, Columbia University New York, New York, 10027, USA
| | - Bonnie Choi
- Department of Chemistry, Columbia University New York, New York, 10027, USA
| | - Shoushou He
- Department of Chemistry, Columbia University New York, New York, 10027, USA
| | - David R Reichman
- Department of Chemistry, Columbia University New York, New York, 10027, USA
| | - Richard A Friesner
- Department of Chemistry, Columbia University New York, New York, 10027, USA
| | - Colin Nuckolls
- Department of Chemistry, Columbia University New York, New York, 10027, USA
| | | | - Xavier Roy
- Department of Chemistry, Columbia University New York, New York, 10027, USA
| | - Ann E McDermott
- Department of Chemistry, Columbia University New York, New York, 10027, USA
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2
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Kimball JJ, Altenhof AR, Jaroszewicz MJ, Schurko RW. Broadband Cross-Polarization to Half-Integer Quadrupolar Nuclei: Wideline Static NMR Spectroscopy. J Phys Chem A 2023; 127:9621-9634. [PMID: 37922436 DOI: 10.1021/acs.jpca.3c05447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2023]
Abstract
Cross-polarization (CP) is a technique commonly used for the signal enhancement of NMR spectra; however, applications to quadrupolar nuclei have heretofore been limited due to a number of problems, including poor spin-locking efficiency, inconvenient relaxation times, and reduced CP efficiencies over broad spectral bandwidths─this is unfortunate, since they constitute 73% of NMR-active nuclei in the periodic table. The Broadband Adiabatic Inversion CP (BRAIN-CP) pulse sequence has proven useful for the signal enhancement of wideline and ultra-wideline (i.e., 250 kHz to several MHz in breadth) powder patterns arising from stationary samples; however, a comprehensive investigation of its application to half-integer quadrupolar nuclei (HIQN) is currently lacking. Herein, we present theoretical and experimental considerations for applying BRAIN-CP to acquire central-transition (CT, +1/2 ↔ -1/2) powder patterns of HIQN. Consideration is given to parameters crucial to the success of the experiment, such as the Hartmann-Hahn (HH) matching conditions and the phase modulation of the contact pulse. Modifications to the BRAIN-CP sequence such as flip-back (FB) pulses and ramped contact pulses applied to the 1H spins are used for the reduction of experimental times and increased CP bandwidth capabilities, respectively. Spectra for a series of quadrupolar nuclei with broad CT powder patterns, including 35Cl (S = 3/2), 55Mn (S = 5/2), 59Co (S = 7/2), and 93Nb (S = 9/2), are acquired via direct excitation (CPMG and WCPMG) and indirect excitation (CP/CPMG and BRAIN-CP) methods. We demonstrate that proper implementation of the sequence can enable 1H-S broadband CP over a bandwidth of 1 MHz, which to the best of our knowledge is the largest CP bandwidth reported to date. Finally, we establish the basic principles necessary for simplified optimization and execution of the BRAIN-CP pulse sequence for a wide range of HIQNs.
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Affiliation(s)
- James J Kimball
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Adam R Altenhof
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Michael J Jaroszewicz
- Department of Chemical & Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Robert W Schurko
- Department of Chemistry & Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
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Leroy C, Bryce DL. Recent advances in solid-state nuclear magnetic resonance spectroscopy of exotic nuclei. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2018; 109:160-199. [PMID: 30527135 DOI: 10.1016/j.pnmrs.2018.08.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 07/18/2018] [Accepted: 08/10/2018] [Indexed: 06/09/2023]
Abstract
We present a review of recent advances in solid-state nuclear magnetic resonance (SSNMR) studies of exotic nuclei. Exotic nuclei may be spin-1/2 or quadrupolar, and typically have low gyromagnetic ratios, low natural abundances, large quadrupole moments (when I > 1/2), or some combination of these properties, generally resulting in low receptivities and/or prohibitively broad line widths. Some nuclides are little studied for other reasons, also rendering them somewhat exotic. We first discuss some of the recent progress in pulse sequences and hardware development which continues to enable researchers to study new kinds of materials as well as previously unfeasible nuclei. This is followed by a survey of applications to a wide range of exotic nuclei (including e.g., 9Be, 25Mg, 33S, 39K, 43Ca, 47/49Ti, 53Cr, 59Co, 61Ni, 67Zn, 73Ge, 75As, 87Sr, 115In, 119Sn, 121/123Sb, 135/137Ba, 185/187Re, 209Bi), most of them quadrupolar. The scope of the review is the past ten years, i.e., 2007-2017.
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Affiliation(s)
- César Leroy
- Department of Chemistry and Biomolecular Sciences & Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario K1N 6N5, Canada
| | - David L Bryce
- Department of Chemistry and Biomolecular Sciences & Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario K1N 6N5, Canada.
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4
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Shen J, Terskikh V, Wu G. A Quadrupole-Central-Transition 59
Co NMR Study of Cobalamins in Solution. Chemphyschem 2018; 20:268-275. [DOI: 10.1002/cphc.201800683] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Jiahui Shen
- Department of Chemistry; Queen's University, 90 Bader Lane, Kingston; Ontario Canada K7L 3N6
| | - Victor Terskikh
- Department of Chemistry; Queen's University, 90 Bader Lane, Kingston; Ontario Canada K7L 3N6
- Department of Chemistry; University of Ottawa, Ottawa; Ontario Canada K1N 6N5
| | - Gang Wu
- Department of Chemistry; Queen's University, 90 Bader Lane, Kingston; Ontario Canada K7L 3N6
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Burgess KMN, Widdifield CM, Xu Y, Leroy C, Bryce DL. Structural Insights from 59 Co Solid-State NMR Experiments on Organocobalt(I) Catalysts. Chemphyschem 2018; 19:227-236. [PMID: 29120533 DOI: 10.1002/cphc.201700990] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 11/08/2017] [Indexed: 11/07/2022]
Abstract
A series of fumarate-based organocobalt(I) [CoCp(CO)(fumarate)] catalysts is synthesized and characterized by X-ray crystallography, multinuclear (13 C and 59 Co) solid-state NMR spectroscopy, and 59 Co NQR spectroscopy. Given the dearth of 59 Co solid-state NMR studies on CoI compounds, the present work constitutes the first systematic characterization of the 59 Co electric field gradient and chemical shift tensors for a series of cobalt complexes in this oxidation state. Using X-ray crystallography, the molecular geometry about the CoI centre is found to be nearly identical in all compounds studied herein. Owing to the 59 Co nucleus' large chemical shift range, solid-state NMR experiments are found to be able to detect small structural differences between the individual organocobalt(I) compounds. With the aid of density functional theory calculations on these complexes, it is shown that the 59 Co chemical shift anisotropy and the 59 Co quadrupolar coupling constant are both extremely sensitive gauges of the Fu-Co-Cp bond angle, providing a link between these 59 Co NMR observables and the catalysts' structures.
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Affiliation(s)
- Kevin M N Burgess
- Department of Chemistry and Biomolecular Sciences, & Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario, K1N 6N5, Canada
- Current address: St. Peter's Seminary, University of Western Ontario, 1040 Waterloo St., London, ON, N6A 3Y1, Canada
| | - Cory M Widdifield
- Department of Chemistry and Biomolecular Sciences, & Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario, K1N 6N5, Canada
- Current address: Oakland University, Department of Chemistry, Mathematics and Science Center, 146 Library Drive, Rochester, MI, 48309-4479, USA
| | - Yang Xu
- Department of Chemistry and Biomolecular Sciences, & Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario, K1N 6N5, Canada
| | - César Leroy
- Department of Chemistry and Biomolecular Sciences, & Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario, K1N 6N5, Canada
| | - David L Bryce
- Department of Chemistry and Biomolecular Sciences, & Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario, K1N 6N5, Canada
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6
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Corzilius B, Michaelis VK, Penzel SA, Ravera E, Smith AA, Luchinat C, Griffin RG. Dynamic nuclear polarization of (1)H, (13)C, and (59)Co in a tris(ethylenediamine)cobalt(III) crystalline lattice doped with Cr(III). J Am Chem Soc 2014; 136:11716-27. [PMID: 25069794 PMCID: PMC4140501 DOI: 10.1021/ja5044374] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The study of inorganic crystalline materials by solid-state NMR spectroscopy is often complicated by the low sensitivity of heavy nuclei. However, these materials often contain or can be prepared with paramagnetic dopants without significantly affecting the structure of the crystalline host. Dynamic nuclear polarization (DNP) is generally capable of enhancing NMR signals by transferring the magnetization of unpaired electrons to the nuclei. Therefore, the NMR sensitivity in these paramagnetically doped crystals might be increased by DNP. In this paper we demonstrate the possibility of efficient DNP transfer in polycrystalline samples of [Co(en)3Cl3]2·NaCl·6H2O (en = ethylenediamine, C2H8N2) doped with Cr(III) in varying concentrations between 0.1 and 3 mol %. We demonstrate that (1)H, (13)C, and (59)Co can be polarized by irradiation of Cr(III) with 140 GHz microwaves at a magnetic field of 5 T. We further explain our findings on the basis of electron paramagnetic resonance spectroscopy of the Cr(III) site and analysis of its temperature-dependent zero-field splitting, as well as the dependence of the DNP enhancement factor on the external magnetic field and microwave power. This first demonstration of DNP transfer from one paramagnetic metal ion to its diamagnetic host metal ion will pave the way for future applications of DNP in paramagnetically doped materials or metalloproteins.
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Affiliation(s)
- Björn Corzilius
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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7
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Wojciechowska A, Dobrzyńska D, Janczak J. Structural and spectroscopic study of cobalt(III) ternary complexes. Polyhedron 2012. [DOI: 10.1016/j.poly.2012.07.101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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9
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Chen F, Ma G, Bernard GM, Cavell RG, McDonald R, Ferguson MJ, Wasylishen RE. Solid-State 115In and 31P NMR Studies of Triarylphosphine Indium Trihalide Adducts. J Am Chem Soc 2010; 132:5479-93. [DOI: 10.1021/ja100625p] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Fu Chen
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Guibin Ma
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Guy M. Bernard
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Ronald G. Cavell
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Robert McDonald
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Michael J. Ferguson
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Roderick E. Wasylishen
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
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10
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Larsen E, Madsen AØ, Kofod P, Song YS. Making a Robust Carbon−Cobalt(III) Bond. Inorg Chem 2009; 48:7159-64. [DOI: 10.1021/ic900397r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Erik Larsen
- IGV, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg, Denmark
| | - Anders Østergaard Madsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Pauli Kofod
- Ankerhus College of Nutrition and Health, Slagelsevej 70-74 DK - 4180 Sorø, Denmark
| | - Yong Sheng Song
- IGV, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg, Denmark
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