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Perras FA, Thomas H, Heintz P, Behera R, Yu J, Viswanathan G, Jing D, Southern SA, Kovnir K, Stanley L, Huang W. The Structure of Boron Monoxide. J Am Chem Soc 2023; 145:14660-14669. [PMID: 37378579 DOI: 10.1021/jacs.3c02070] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Boron monoxide (BO), prepared by the thermal condensation of tetrahydroxydiboron, was first reported in 1955; however, its structure could not be determined. With the recent attention on boron-based two-dimensional materials, such as borophene and hexagonal boron nitride, there is renewed interest in BO. A large number of stable BO structures have been computationally identified, but none are supported by experiments. The consensus is that the material likely forms a boroxine-based two-dimensional material. Herein, we apply advanced 11B NMR experiments to determine the relative orientations of B(B)O2 centers in BO. We find that the material is composed of D2h-symmetric O2B-BO2 units that organize to form larger B4O2 rings. Further, powder diffraction experiments additionally reveal that these units organize to form two-dimensional layers with a random stacking pattern. This observation is in agreement with earlier density functional theory (DFT) studies that showed B4O2-based structures to be the most stable.
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Affiliation(s)
- Frédéric A Perras
- Chemical and Biological Sciences Division, Ames National Laboratory, Ames, Iowa 50011, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Henry Thomas
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Patrick Heintz
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Ranjan Behera
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Jiaqi Yu
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Gayatri Viswanathan
- Chemical and Biological Sciences Division, Ames National Laboratory, Ames, Iowa 50011, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Dapeng Jing
- Materials Analysis and Research Laboratory, Iowa State University, Ames, Iowa 50011, United States
| | - Scott A Southern
- Chemical and Biological Sciences Division, Ames National Laboratory, Ames, Iowa 50011, United States
| | - Kirill Kovnir
- Chemical and Biological Sciences Division, Ames National Laboratory, Ames, Iowa 50011, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Levi Stanley
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Wenyu Huang
- Chemical and Biological Sciences Division, Ames National Laboratory, Ames, Iowa 50011, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
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Bayzou R, Trébosc J, Hung I, Gan Z, Rankin A, Lafon O, Amoureux JP. Improved resolution for spin-3/2 isotopes in solids via the indirect NMR detection of triple-quantum coherences using the T-HMQC sequence. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2022; 122:101835. [PMID: 36308816 DOI: 10.1016/j.ssnmr.2022.101835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 10/10/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
The indirect NMR detection of quadrupolar nuclei in solids under magic-angle spinning (MAS) is possible with the through-space HMQC (heteronuclear multiple-quantum coherence) scheme incorporating the TRAPDOR (transfer of population in double-resonance) dipolar recoupling. This sequence, called T-HMQC, exhibits limited t1-noise. In this contribution, with the help of numerical simulations of spin dynamics, we show that most of the time, the fastest coherence transfer in the T-HMQC scheme is achieved when TRAPDOR recoupling employs the highest radiofrequency (rf) field compatible with the probe specifications. We also demonstrate how the indirect detection of the triple-quantum (3Q) coherences of spin-3/2 quadrupolar nuclei in solids improves the spectral resolution for these isotopes. The sequence is then called T-HMQC3. We demonstrate the gain in resolution provided by this sequence for the indirect proton detection of 35Cl nuclei in l-histidine∙HCl and l-cysteine∙HCl, as well as that of 23Na isotope in NaH2PO4. These experiments indicate that the gain in resolution depends on the relative values of the chemical and quadrupolar-induced shifts (QIS) for the different spin-3/2 species. In the case of NaH2PO4, we show that the transfer efficiency of the T-HMQC3 sequence employing an rf-field of 80 kHz with a MAS frequency of 62.5 kHz reaches 75% of that of the t1-noise eliminated (TONE) dipolar-mediated HMQC (D-HMQC) scheme.
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Affiliation(s)
- Racha Bayzou
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie, du Solide, 59000, Lille, France
| | - Julien Trébosc
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie, du Solide, 59000, Lille, France; Univ. Lille, CNRS, INRAE, Centrale Lille, Univ. Artois, FR 2638 - IMEC - Fédération Chevreul, 59000, Lille, France
| | - Ivan Hung
- National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, FL, 32310, USA
| | - Zhehong Gan
- National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, FL, 32310, USA
| | - Andrew Rankin
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie, du Solide, 59000, Lille, France; Univ. Lille, CNRS, INRAE, Centrale Lille, Univ. Artois, FR 2638 - IMEC - Fédération Chevreul, 59000, Lille, France
| | - Olivier Lafon
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie, du Solide, 59000, Lille, France
| | - Jean-Paul Amoureux
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie, du Solide, 59000, Lille, France; Bruker Biospin, 34 rue de l'industrie, 67166, Wissembourg, France.
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Sasaki A, Trébosc J, Nagashima H, Amoureux JP. Practical considerations on the use of low RF-fields and cosine modulation in high-resolution NMR of I = 3/2 spin quadrupolar nuclei in solids. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 345:107324. [PMID: 36370548 DOI: 10.1016/j.jmr.2022.107324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/26/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
Despite its ease in experimental set up, the low sensitivity of MQMAS experiments is often a limiting factor in many practical applications. This is mainly due to the large radiofrequency (RF) field requirement of the two short hard-pulses often used for the optimum MQ excitation and conversion steps. Very recently, two novel MQMAS experiments have been proposed for I = 3/2 nuclei, namely lp-MQMAS and coslp-MQMAS, enabling an efficient MQ excitation/conversion with a reduced RF requirement, by utilizing two long pulses lasting one rotor period each, with or without cosine modulation. In this study, we focus on the practical considerations of these new methods and discuss their pros and cons to elucidate their appropriate use under both moderate and fast spinning conditions. Using four I = 3/2 (87Rb, 71Ga, 35Cl and 23Na) nuclei at a moderate magnetic field (B0 = 14.1 T), we show the superior use of these experiments, especially for samples with large CQ values and/or low-gamma nuclei. Compared to all other existing sequences, the coslp-MQMAS method with initial WURST signal enhancement is the most robust, efficient and resolved high-resolution 2D method for spin 3/2 nuclei. Furthermore, using {23Na}-1H spin systems, we demonstrate the sensitivity advantage of the WURST coslp-MQ-HETCOR acquisition upon 1H detection and fast MAS conditions.
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Affiliation(s)
- Akiko Sasaki
- Interdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan; Bruker Japan K.K., 3-9, Moriya-cho, Kanagawa-ku, Yokohama-shi, Kanagawa 221-0022, Japan
| | - Julien Trébosc
- Univ. Lille, CNRS, INRAE, Centrale Lille, Univ. Artois, FR 2638 - IMEC - Institut Michel-Eugène Chevreul, F-59000 Lille, France
| | - Hiroki Nagashima
- Interdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Jean-Paul Amoureux
- Bruker Biospin, 34 rue de l'industrie, F-67166 Wissembourg, France; Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unit of Catalysis and Chemistry of Solids, F-59000 Lille, France
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Smith ME. Recent progress in solid-state NMR of spin-½ low-γ nuclei applied to inorganic materials. Phys Chem Chem Phys 2022; 25:26-47. [PMID: 36421944 DOI: 10.1039/d2cp03663k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Significant technological and methodological advances in solid-state NMR techniques in recent years have increased the accessibility of nuclei with small magnetic moments (hereafter termed low-γ) underpinning an increased range of applications of such nuclei. These methodological advances are briefly summarised, including improvements in hardware and pulse sequences, as well as important developments in associated computational methods (e.g. first principles calculations, spectral simulation). Here spin-½ nuclei are the focus, with this Perspective complementing a very recent review that looked at half-integer spin low-γ quadrupolar nuclei. Reference is made to some of the original reports of such spin-½ nuclei, but recent progress in the relevant methodology and applications to inorganic materials (most within the last 10 years) of these nuclei are the focus. An overview of the current state-of-the-art of studying these nuclei is thereby provided for both NMR spectroscopists and materials researchers.
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Affiliation(s)
- Mark E Smith
- Vice-Chancellor and President's Office and Department of Chemistry, University of Southampton, Southampton, SO17 1BJ, UK. .,Department of Chemistry, Lancaster University, Bailrigg, Lancaster, LA1 4YB, UK.,Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
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