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Xiao H, Zhang Z, Kang H, Yang J. Solid-State NMR Double-Quantum Dipolar Recoupling Enhanced by Additional Phase Modulation. Chemphyschem 2023; 24:e202300141. [PMID: 37309720 DOI: 10.1002/cphc.202300141] [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: 02/23/2023] [Revised: 06/02/2023] [Accepted: 06/12/2023] [Indexed: 06/14/2023]
Abstract
Additional phase modulation (APM) is proposed to generally enhance the theoretical efficiency of homonuclear double-quantum (DQ) recoupling in solid-state NMR. APM applies an additional phase list to DQ recoupling in steps of an entire block. The sine-based phase list can enhance the theoretical efficiency by 15-30 %, from 0.52 to 0.68 (non-γ-encoded recoupling) or from 0.73 to 0.84 (γ-encoded recoupling), with doubled recoupling time. The genetic-algorithm (GA) optimized APM can adiabatically enhance the efficiency to ∼1.0 at longer times. The concept of APM has been tested on SPR-51 , BaBa, and SPR-31 , which represent γ-encoded recoupling, non-γ-encoded recoupling, and another kind beyond the former two, respectively. Simulations reveal that enhancements from APM are due to the activation of more crystallites in the powder. Experiments on 2,3-13 C labeled alanine are used to validate the APM recoupling. This new concept shall shed light on developing more efficient homonuclear recoupling methods.
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Affiliation(s)
- Hang Xiao
- National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, Hubei, 430071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhengfeng Zhang
- National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, Hubei, 430071, China
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Huimin Kang
- National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, Hubei, 430071, China
| | - Jun Yang
- National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, Hubei, 430071, China
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
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Altenhof AR, Gan Z, Schurko RW. Reducing the effects of weak homonuclear dipolar coupling with CPMG pulse sequences for static and spinning solids. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 337:107174. [PMID: 35279507 DOI: 10.1016/j.jmr.2022.107174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 06/14/2023]
Abstract
The Carr-Purcell/Meiboom-Gill (CPMG) pulse sequence, initially introduced for measuring transverse relaxation time constants (T2), can provide significant signal enhancements for solid-state NMR (SSNMR) spectra. The proper implementation of CPMG for acquiring spectra influenced by chemical shift anisotropies (CSAs), first and/or second order quadrupolar interactions, or paramagnetic broadening has been well documented to date, as have the effects of heteronuclear dipolar coupling on CPMG echo trains and T2 lifetimes. Homonuclear dipolar coupling can also impact T2 lifetimes and CPMG echo trains; these effects have been thoroughly investigated for spectra of homonuclear dipolar coupled spin-1/2 nuclei typically acquired under static conditions that are predominantly influenced by dipolar broadening (e.g., 1H, 19F, etc.). In particular, it has been shown that short refocusing pulses with small flip angles can extend the effective T2 (T2eff, the observed T2 constant as impacted by experimental conditions) measured by CPMG sequences for strong homonuclear dipolar coupled spin-1/2 pairs under static conditions. To date, these effects have not been explored for (i) spin-1/2 nuclei that have significant CSAs and simultaneously feature weak homonuclear dipolar couplings, (ii) for quadrupolar nuclei that are also weakly homonuclear dipolar coupled, and (iii) for either of these cases under magic-angle spinning (MAS) conditions. Herein, we demonstrate that short refocusing pulses that cause small flip angles can reduce the attenuation of signal in CPMG echo trains resulting from dipolar dephasing caused by the weak homonuclear dipolar couplings. For both spin-1/2 and quadrupolar nuclei, this can lead to significant extensions in T2eff and signal enhancements of up to three times compared to conventional CPMG in favourable cases. These phenomena can occur under both static and magic-angle spinning (MAS) conditions, in the latter of which homonuclear couplings are reintroduced by rotational resonance (R2) recoupling. Experimental examples of 13C (I = 1/2), 2H (I = 1), 87Rb (I = 3/2), 23Na (I = 3/2), and 35Cl (I = 3/2) NMR under static and MAS conditions, as well as simulations of these phenomena, are shown and discussed.
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Affiliation(s)
- Adam R Altenhof
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA; 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
| | - Robert W Schurko
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA; National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, FL 32310, USA.
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3
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Duong NT, Lee D, Mentink-Vigier F, Lafon O, De Paëpe G. On the use of radio-frequency offsets for improving double-quantum homonuclear dipolar recoupling of half-integer-spin quadrupolar nuclei. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2021; 59:991-1008. [PMID: 33624858 DOI: 10.1002/mrc.5142] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 02/15/2021] [Accepted: 02/19/2021] [Indexed: 06/12/2023]
Abstract
Detecting proximities between nuclei is crucial for atomic-scale structure determination with nuclear magnetic resonance (NMR) spectroscopy. Different from spin-1/2 nuclei, the methodology for quadrupolar nuclei is limited for solids due to the complex spin dynamics under simultaneous magic-angle spinning (MAS) and radio-frequency irradiation. Herein, the performances of several homonuclear rotary recoupling (HORROR)-based homonuclear dipolar recoupling sequences are evaluated for 27 Al (spin-5/2). It is shown numerically and experimentally on mesoporous alumina that BR 2 2 1 outperforms the supercycled S3 sequence and its pure double-quantum (DQ) (bracketed) version, [S3 ], both in terms of DQ transfer efficiency and bandwidth. This result is surprising since the S3 sequence is among the best low-power recoupling schemes for spin-1/2. The superiority of BR 2 2 1 is thoroughly explained, and the crucial role of radio-frequency offsets during its spin dynamics is highlighted. The analytical approximation of BR 2 2 1 , derived in an offset-toggling frame, clarifies the interplay between offset and DQ efficiency, namely, the benefits of off-resonance irradiation and the trough in DQ efficiency for BR 2 2 1 when the irradiation is central between two resonances, both for spin-1/2 and half-integer-spin quadrupolar nuclei. Additionally, density matrix propagations show that the BR 2 2 1 sequence, applied to quadrupolar nuclei subject to quadrupolar interaction much larger than radio-frequency frequency field, can create single- and multiple-quantum coherences for near on-resonance irradiation. This significantly perturbs the creation of DQ coherences between central transitions of neighboring quadrupolar nuclei. This effect explains the DQ efficiency trough for near on-resonance irradiation, in the case of both cross-correlation and autocorrelation peaks. Overall, this work aids experimental acquisition of homonuclear dipolar correlation spectra of half-integer-spin quadrupolar nuclei and provides theoretical insights towards improving recoupling schemes at high magnetic field and fast MAS.
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Affiliation(s)
- Nghia Tuan Duong
- Univ. Grenoble Alpes, CEA, IRIG-MEM, Grenoble, 38000, France
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, Lille, F-59000, France
| | - Daniel Lee
- Univ. Grenoble Alpes, CEA, IRIG-MEM, Grenoble, 38000, France
| | | | - Olivier Lafon
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, Lille, F-59000, France
- Institut Universitaire de France, Paris, 75231, France
| | - Gaël De Paëpe
- Univ. Grenoble Alpes, CEA, IRIG-MEM, Grenoble, 38000, France
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Yu Y, Keil P, Stevensson B, Hansen MR, Edén M. Assessment of new symmetry-based dipolar recoupling schemes for homonuclear magnetization exchange between quadrupolar nuclei in two-dimensional correlation MAS NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 316:106734. [PMID: 32590307 DOI: 10.1016/j.jmr.2020.106734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/13/2020] [Accepted: 04/15/2020] [Indexed: 06/11/2023]
Abstract
We provide an extensive experimental and numerical evaluation of MQ-phase (S)M supercycles with M={3,4} of three groups of symmetry-based homonuclear dipolar recoupling rf-pulse sequences, [Formula: see text] , for establishing proximities among half-integer spin quadrupolar nuclei under moderately fast magic-angle-spinning (MAS) conditions in single-quantum-single-quantum (1Q-1Q) correlation NMR experiments. The relative merits of the (S)M schemes for variations in resonance offsets and rf-amplitude errors were assessed by numerically simulated magnetization transfers in spin-3/2 pairs with variable isotropic chemical shifts and quadrupolar coupling constants. Experimental demonstrations of 23Na (spin-3/2) NMR on Na2MoO4·2H2O and 27Al (spin-5/2) NMR on AlPO-CJ19 [(NH4)2Al4(PO4)4HPO4·H2O] are presented at 14.1 T and 24 kHz MAS. We recommend using the (SR221)3 or (SR221)4 supercycles for samples that exhibit small chemical-shift dispersions (<3 kHz), and any (SRNNN/2)3 scheme with N⩾10 for larger spreads of isotropic chemical shifts. However, because the (SRNNN/2)3 sequences recouple heteronuclear dipolar interactions, their application to proton-bearing samples requires high-power proton decoupling during the mixing period. Alternatively, the (SR241)3 and (SR241)4 schemes may be employed in the absence of proton decoupling, but with poorer compensation to resonance-offsets and rf-amplitude errors.
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Affiliation(s)
- Yang Yu
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Philipp Keil
- Institute for Physical Chemistry, Westfälische Wilhelms-Universität Münster, DE-48 149 Münster, Germany
| | - Baltzar Stevensson
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Michael Ryan Hansen
- Institute for Physical Chemistry, Westfälische Wilhelms-Universität Münster, DE-48 149 Münster, Germany
| | - Mattias Edén
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
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Yu Y, Keil P, Hansen MR, Edén M. Improved Magnetization Transfers among Quadrupolar Nuclei in Two-Dimensional Homonuclear Correlation NMR Experiments Applied to Inorganic Network Structures. Molecules 2020; 25:molecules25020337. [PMID: 31947638 PMCID: PMC7024165 DOI: 10.3390/molecules25020337] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 01/08/2020] [Accepted: 01/09/2020] [Indexed: 11/17/2022] Open
Abstract
We demonstrate that supercycles of previously introduced two-fold symmetry dipolar recoupling schemes may be utilized successfully in homonuclear correlation nuclear magnetic resonance (NMR) spectroscopy for probing proximities among half-integer spin quadrupolar nuclei in network materials undergoing magic-angle-spinning (MAS). These (SR221)M, (SR241)M, and (SR281)M recoupling sequences with M=3 and M=4 offer comparably efficient magnetization transfers in single-quantum–single-quantum (1Q–1Q) correlation NMR experiments under moderately fast MAS conditions, as demonstrated at 14.1 T and 24 kHz MAS in the contexts of 11B NMR on a Na2O–CaO–B2O3–SiO2 glass and 27Al NMR on the open framework aluminophosphate AlPO-CJ19 [(NH4)2Al4(PO4)4HPO4·H2O]. Numerically simulated magnetization transfers in spin–3/2 pairs revealed a progressively enhanced tolerance to resonance offsets and rf-amplitude errors of the recoupling pulses along the series (SR221)M< (SR241)M< (SR281)M for increasing differences in chemical shifts between the two nuclei. Nonetheless, for scenarios of a relatively minor chemical-shift dispersions (≲3 kHz), the (SR221)M supercycles perform best both experimentally and in simulations.
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Affiliation(s)
- Yang Yu
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden;
| | - Philipp Keil
- Institute for Physical Chemistry, Westfälische Wilhelms-Universität Münster, DE-48 149 Münster, Germany; (P.K.); (M.R.H.)
| | - Michael Ryan Hansen
- Institute for Physical Chemistry, Westfälische Wilhelms-Universität Münster, DE-48 149 Münster, Germany; (P.K.); (M.R.H.)
| | - Mattias Edén
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden;
- Correspondence:
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Yu Y, Stevensson B, Pujari-Palmer M, Guo H, Engqvist H, Edén M. The Monetite Structure Probed by Advanced Solid-State NMR Experimentation at Fast Magic-Angle Spinning. Int J Mol Sci 2019; 20:ijms20246356. [PMID: 31861132 PMCID: PMC6940740 DOI: 10.3390/ijms20246356] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/10/2019] [Accepted: 12/12/2019] [Indexed: 01/29/2023] Open
Abstract
We present a solid-state nuclear magnetic resonance (NMR) spectroscopy study of the local 31P and 1H environments in monetite [CaHPO4; dicalcium phosphate anhydrous (DCPA)], as well as their relative spatial proximities. Each of the three 1H NMR peaks was unambiguously assigned to its respective crystallographically unique H site of monetite, while their pairwise spatial proximities were probed by homonuclear 1H–1H double quantum–single quantum NMR experimentation under fast magic-angle spinning (MAS) of 66 kHz. We also examined the relative 1H–31P proximities among the inequivalent {P1, P2} and {H1, H2, H3} sites in monetite; the corresponding shortest internuclear 1H–31P distances accorded well with those of a previous neutron diffraction study. The NMR results from the monetite phase were also contrasted with those observed from the monetite component present in a pyrophosphate-bearing calcium phosphate cement, demonstrating that while the latter represents a disordered form of monetite, it shares all essential local features of the monetite structure.
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Affiliation(s)
- Yang Yu
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden; (Y.Y.); (B.S.); (H.G.)
| | - Baltzar Stevensson
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden; (Y.Y.); (B.S.); (H.G.)
| | - Michael Pujari-Palmer
- Applied Material Science, Department of Engineering, Uppsala University, SE-751 21 Uppsala, Sweden; (M.P.-P.); (H.E.)
| | - Hua Guo
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden; (Y.Y.); (B.S.); (H.G.)
| | - Håkan Engqvist
- Applied Material Science, Department of Engineering, Uppsala University, SE-751 21 Uppsala, Sweden; (M.P.-P.); (H.E.)
| | - Mattias Edén
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden; (Y.Y.); (B.S.); (H.G.)
- Correspondence:
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7
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Gvozdetskyi V, Hanrahan MP, Ribeiro RA, Kim T, Zhou L, Rossini AJ, Canfield PC, Zaikina JV. A Hydride Route to Ternary Alkali Metal Borides: A Case Study of Lithium Nickel Borides. Chemistry 2019; 25:4123-4135. [DOI: 10.1002/chem.201805398] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Indexed: 11/12/2022]
Affiliation(s)
| | - Michael P. Hanrahan
- Department of ChemistryIowa State University Ames Iowa 50011 United States
- Ames Laboratory, US DOEIowa State University Ames Iowa 50011 United States
| | - Raquel A. Ribeiro
- Department of Physics and AstronomyIowa State University Ames Iowa 50011 United States
- CCNHUniversidade Federal do ABC (UFABC) Santo André SP 09210-580 Brazil
| | - Tae‐Hoon Kim
- Ames Laboratory, US DOEIowa State University Ames Iowa 50011 United States
| | - Lin Zhou
- Ames Laboratory, US DOEIowa State University Ames Iowa 50011 United States
| | - Aaron J. Rossini
- Department of ChemistryIowa State University Ames Iowa 50011 United States
- Ames Laboratory, US DOEIowa State University Ames Iowa 50011 United States
| | - Paul C. Canfield
- Ames Laboratory, US DOEIowa State University Ames Iowa 50011 United States
- Department of Physics and AstronomyIowa State University Ames Iowa 50011 United States
| | - Julia V. Zaikina
- Department of ChemistryIowa State University Ames Iowa 50011 United States
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Yu Y, Stevensson B, Edén M. Direct Experimental Evidence for Abundant BO 4-BO 4 Motifs in Borosilicate Glasses From Double-Quantum 11B NMR Spectroscopy. J Phys Chem Lett 2018; 9:6372-6376. [PMID: 30354174 DOI: 10.1021/acs.jpclett.8b02907] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
By using double-quantum-single-quantum correlation 11B nuclear magnetic resonance (NMR) experiments and atomistic molecular dynamics (MD) simulations, we resolve the long-standing controversy of whether directly interlinked BO4-BO4 groups exist in the technologically ubiquitous class of alkali/alkaline-earth based borosilicate (BS) glasses. Most structural models of Na2O-B2O3-SiO2 glasses assume the absence of B[4]-O-B[4] linkages, whereas they have been suggested to exist in Ca-bearing BS analogs. Our results demonstrate that while B[4]-O-B[4] linkages are disfavored relative to their B[3]-O-B[3]/B[4] counterparts, they are nevertheless abundant motifs in Na2O-B2O3-SiO2 glasses over a large composition space, while the B[4]-O-B[4] contents are indeed elevated in Na2O-CaO-B2O3-SiO2 glasses. We discuss the compositional and structural parameters that control the degree of B[4]-O-B[4] bonding.
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Affiliation(s)
- Yang Yu
- Physical Chemistry Division, Department of Materials and Environmental Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Baltzar Stevensson
- Physical Chemistry Division, Department of Materials and Environmental Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Mattias Edén
- Physical Chemistry Division, Department of Materials and Environmental Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
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Ganapathy V, Ramachandran R. Effective Floquet Hamiltonian theory of multiple-quantum NMR in anisotropic solids involving quadrupolar spins: Challenges and Perspectives. J Chem Phys 2017; 147:144202. [DOI: 10.1063/1.4993313] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Vinay Ganapathy
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Mohali 140306, Punjab, India
| | - Ramesh Ramachandran
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Mohali 140306, Punjab, India
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Yu Y, Stevensson B, Edén M. Medium-Range Structural Organization of Phosphorus-Bearing Borosilicate Glasses Revealed by Advanced Solid-State NMR Experiments and MD Simulations: Consequences of B/Si Substitutions. J Phys Chem B 2017; 121:9737-9752. [PMID: 28876931 DOI: 10.1021/acs.jpcb.7b06654] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The short and intermediate range structures of a large series of bioactive borophosphosilicate (BPS) glasses were probed by solid-state nuclear magnetic resonance (NMR) spectroscopy and atomistic molecular dynamics (MD) simulations. Two BPS glass series were designed by gradually substituting SiO2 by B2O3 in the respective phosphosilicate base compositions 24.1Na2O-23.3CaO-48.6SiO2-4.0P2O5 ("S49") and 24.6Na2O-26.7CaO-46.1SiO2-2.6P2O5 ("S46"), the latter constituting the "45S5 Bioglass" utilized for bone grafting applications. The BPS glass networks are built by interconnected SiO4, BO4, and BO3 moieties, whereas P exists mainly as orthophosphate anions, except for a minor network-associated portion involving P-O-Si and P-O-B[4] motifs, whose populations were estimated by heteronuclear 31P{11B} NMR experimentation. The high Na+/Ca2+ contents give fragmented glass networks with large amounts of nonbridging oxygen (NBO) anions. The MD-generated glass models reveal an increasing propensity for NBO accommodation among the network units according to BO4 < SiO4 < BO3 ≪ PO4. The BO4/BO3 intermixing was examined by double-quantum-single-quantum correlation 11B NMR experiments, which evidenced the presence of all three BO3-BO3, BO3-BO4, and BO4-BO4 connectivities, with B[3]-O-B[4] bridges dominating. Notwithstanding that B[4]-O-B[4] linkages are disfavored, both NMR spectroscopy and MD simulations established their presence in these modifier-rich BPS glasses, along with non-negligible B[4]-NBO contacts, at odds with the conventional structural view of borosilicate glasses. We discuss the relative propensities for intermixing of the Si/B/P network formers. Despite the absence of pronounced preferences for Si-O-Si bond formation, the glass models manifest subtle subnanometer-sized structural inhomogeneities, where SiO4 tetrahedra tend to self-associate into small chain/ring motifs embedded in BO3/BO4-dominated domains.
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Affiliation(s)
- Yang Yu
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Stockholm University , SE-106 91 Stockholm, Sweden
| | - Baltzar Stevensson
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Stockholm University , SE-106 91 Stockholm, Sweden
| | - Mattias Edén
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Stockholm University , SE-106 91 Stockholm, Sweden
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11
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Martineau-Corcos C, Dědeček J, Taulelle F. 27Al- 27Al double-quantum single-quantum MAS NMR: Applications to the structural characterization of microporous materials. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2017; 84:65-72. [PMID: 28089089 DOI: 10.1016/j.ssnmr.2016.12.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 12/21/2016] [Accepted: 12/27/2016] [Indexed: 06/06/2023]
Abstract
In this paper, we review and illustrate applications, reported in the literature or used in our group, of 27Al-27Al double-quantum single-quantum (DQ-SQ) MAS NMR experiments for the structural characterization of Al-containing microporous solids, namely zeolites, aluminophosphates and metal-organic frameworks. Information regarding the periodic frameworks or the localization of the various aluminum species in the materials are obtained from the analysis of the two-dimensional NMR spectra, which allows getting local structural details sometimes inaccessible from other characterization technique. An application of 27Al-27Al of the DQ-SQ experiment for the detection of aluminum pairing in zeolite is shown.
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Affiliation(s)
- Charlotte Martineau-Corcos
- Institut Lavoisier de Versailles, CNRS UMR 8180, Université de Versailles Saint-Quentin en Yvelines, 45 Avenue des Etats-Unis, Versailles Cedex 78035, France; CNRS, CEMHTI UPR3079, Université d'Orléans, Orléans F-45071, France.
| | - Jiri Dědeček
- J. Heyrovsky Institute of Physical Chemistry, Dolejskova 3, Prague 8 CZ 182 23, Czechia
| | - Francis Taulelle
- Institut Lavoisier de Versailles, CNRS UMR 8180, Université de Versailles Saint-Quentin en Yvelines, 45 Avenue des Etats-Unis, Versailles Cedex 78035, France
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12
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Perras FA. Quantitative structure parameters from the NMR spectroscopy of quadrupolar nuclei. PURE APPL CHEM 2016. [DOI: 10.1515/pac-2015-0801] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractNuclear magnetic resonance (NMR) spectroscopy is one of the most important characterization tools in chemistry, however, 3/4 of the NMR active nuclei are underutilized due to their quadrupolar nature. This short review centers on the development of methods that use solid-state NMR of quadrupolar nuclei for obtaining quantitative structural information. Namely, techniques using dipolar recoupling as well as the resolution afforded by double-rotation are presented for the measurement of spin–spin coupling between quadrupoles, enabling the measurement of internuclear distances and connectivities. Two-dimensional J-resolved-type experiments are then presented for the measurement of dipolar and J coupling, between spin-1/2 and quadrupolar nuclei as well as in pairs of quadrupolar nuclei. Select examples utilizing these techniques for the extraction of structural information are given. Techniques are then described that enable the fine refinement of crystalline structures using solely the electric field gradient tensor, measured using NMR, as a constraint. These approaches enable the solution of crystal structures, from polycrystalline compounds, that are of comparable quality to those solved using single-crystal diffraction.
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Affiliation(s)
- Frédéric A. Perras
- 1Ames Laboratory, Iowa State University, 211 Spedding Hall, Ames, IA 50011-3020, USA
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13
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Yu Y, Edén M. Structure–composition relationships of bioactive borophosphosilicate glasses probed by multinuclear 11B, 29Si, and 31P solid state NMR. RSC Adv 2016. [DOI: 10.1039/c6ra15275a] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
By combining 11B, 29Si, and 31P nuclear magnetic resonance (NMR) experimental results, we present the first comprehensive structural investigation of 15 borophosphosilicate (BPS) glasses of the Na2O–CaO–B2O3–SiO2–P2O5 system.
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Affiliation(s)
- Yang Yu
- Physical Chemistry Division
- Department of Materials and Environmental Chemistry
- Stockholm University
- SE-106 91 Stockholm
- Sweden
| | - Mattias Edén
- Physical Chemistry Division
- Department of Materials and Environmental Chemistry
- Stockholm University
- SE-106 91 Stockholm
- Sweden
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14
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Teymoori G, Pahari B, Edén M. Low-power broadband homonuclear dipolar recoupling in MAS NMR by two-fold symmetry pulse schemes for magnetization transfers and double-quantum excitation. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 261:205-20. [PMID: 26515279 DOI: 10.1016/j.jmr.2015.09.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 08/31/2015] [Accepted: 09/07/2015] [Indexed: 05/28/2023]
Abstract
We provide an experimental, numerical, and high-order average Hamiltonian evaluation of an open-ended series of homonuclear dipolar recoupling sequences, SR [Formula: see text] with p=1,2,3,…. While operating at a very low radio-frequency (rf) power, corresponding to a nutation frequency of 1/2 of the magic-angle spinning (MAS) rate (ωnut=ωr/2), these recursively generated double-quantum (2Q) dipolar recoupling schemes offer a progressively improved compensation to resonance offsets and rf inhomogeneity for increasing pulse-sequence order p. The excellent recoupling robustness to these experimental obstacles, as well as to CSA, is demonstrated for 2Q filtering (2QF) experiments and for driving magnetization transfers in 2D NMR correlation spectroscopy, where the sequences may provide either double or zero quantum dipolar Hamiltonians during mixing. Experimental and numerical demonstrations, which mostly target conditions of "ultra-fast" MAS (≳50kHz) and high magnetic fields, are provided for recoupling of (13)C across a wide range of isotropic and anisotropic chemical shifts, as well as dipolar coupling constants, encompassing [2,3-(13)C2]alanine, [1,3-(13)C2]alanine, diammonium [1,4-(13)C2]fumarate, and [U-(13)C]tyrosine. When compared at equal power levels, a superior performance is observed for the SR [Formula: see text] sequences with p⩾3 relative to existing and well-established 2Q recoupling techniques. At ultra-fast MAS, proton decoupling is redundant during the homonuclear dipolar recoupling of dilute spins in organic solids, which renders the family of SR [Formula: see text] schemes the first efficient 2Q recoupling option for general applications, such as 2Q-1Q correlation NMR and high-order multiple-quantum excitation, under truly low-power rf conditions.
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Affiliation(s)
- Gholamhasan Teymoori
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Bholanath Pahari
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Mattias Edén
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden.
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Yesinowski JP. Finding the true spin-lattice relaxation time for half-integral nuclei with non-zero quadrupole couplings. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 252:135-144. [PMID: 25700115 DOI: 10.1016/j.jmr.2014.12.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 12/17/2014] [Accepted: 12/23/2014] [Indexed: 06/04/2023]
Abstract
Measuring true spin-lattice relaxation times T(1) of half-integral quadrupolar nuclei having non-zero nuclear quadrupole coupling constants (NQCCs) presents challenges due to the presence of satellite-transitions (STs) that may lie outside the excitation bandwidth of the central transition (CT). This leads to complications in establishing well-defined initial conditions for the population differences in these multi-level systems. In addition, experiments involving magic-angle spinning (MAS) can introduce spin exchange due to zero-crossings of the ST and CT (or possibly rotational resonance recoupling in the case of multiple sites) and greatly altered initial conditions as well. An extensive comparison of pulse sequences that have been previously used to measure T(1) in such systems is reported, using the (71)Ga (I=3/2) NMR of a Ge-doped h-GaN n-type semiconductor sample as the test case. The T(1) values were measured at the peak maximum of the Knight shift distribution. Analytical expressions for magnetization-recovery of the CT appropriate to the pulse sequences tested were used, involving contributions from both a magnetic relaxation mechanism (rate constant W) and a quadrupolar one (rate constants W(1) and W(2), approximately equal in this case). An asynchronous train of high-power saturating pulses under MAS that is able to completely saturate both CT and STs is found to be the most reliable and accurate method for obtaining the "true T(1)", defined here as (2W+2W1,2)(-)(1). All other methods studied yielded poor agreement with this "true T(1)" value or even resulted in gross errors, for reasons that are analyzed in detail. These methods involved a synchronous train of saturating pulses under MAS, an inversion-recovery sequence under MAS or static conditions, and a saturating comb of pulses on a static sample. Although the present results were obtained on a sample where the magnetic relaxation mechanism dominated the quadrupolar one, the asynchronous saturating pulse train approach is not limited to this situation. The extent to which W(1) and W(2) are unequal does affect the interpretability of the experiment however, particularly when the quadrupolar mechanism dominates. A numerically approximate solution for the I=3/2 recovery case reveals the quantitative effects of any such inequality.
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Affiliation(s)
- James P Yesinowski
- Chemistry Division, Naval Research Laboratory, Washington, DC 20375-5342, USA.
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16
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Iuga D, Holland D, Dupree R. A 3D experiment that provides isotropic homonuclear correlations of half-integer quadrupolar nuclei. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 246:122-129. [PMID: 25123541 DOI: 10.1016/j.jmr.2014.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 06/30/2014] [Accepted: 07/09/2014] [Indexed: 06/03/2023]
Abstract
Two 3D experiments, capable of producing enhanced resolution two-spin double-quantum (DQ) homonuclear correlations for half-integer quadrupolar nuclei, are described. The first uses a split-t1 MQMAS sequence followed by a sandwiched oR(3) symmetry-based dipolar recoupling sequence to directly excite DQ coherences. In this case an isotropic single-quantum (SQ) coherence starts the homonuclear DQ excitation. In the second experiment a single strong pulse is used to create triple quantum (TQ) coherence followed by a further single pulse conversion to zero-order before a non-sandwiched oR(3) DQ sequence. The first experiment is demonstrated using (87)Rb in RbNO3, with three Rb sites in a ∼5ppm range, and the second to (11)B in caesium triborate, CsB3O5, with two three-coordinated sites separated by ∼2ppm and one four-coordinated boron site. In both cases, all sites are clearly resolved and their connections observed. The second experiment has higher sensitivity and a good signal to noise is obtained in a reasonable time despite the long T1 relaxation time of (11)B in this material.
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Affiliation(s)
- Dinu Iuga
- Physics Department, University of Warwick, CV4 7AL Coventry, UK.
| | - Diane Holland
- Physics Department, University of Warwick, CV4 7AL Coventry, UK
| | - Ray Dupree
- Physics Department, University of Warwick, CV4 7AL Coventry, UK
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17
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Brinkmann A, Edén M. Central-transition double-quantum sideband NMR spectroscopy of half-integer quadrupolar nuclei: estimating internuclear distances and probing clusters within multi-spin networks. Phys Chem Chem Phys 2014; 16:7037-50. [DOI: 10.1039/c4cp00029c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Clusters within quadrupolar spin networks are probed and internuclear distances between quadrupolar nuclei are estimated by central-transition double-quantum sideband NMR spectroscopy.
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Affiliation(s)
- Andreas Brinkmann
- Measurement Science and Standards
- National Research Council Canada
- Ottawa, Canada
| | - Mattias Edén
- Physical Chemistry Division
- Department of Materials and Environmental Chemistry
- Arrhenius Laboratory
- Stockholm University
- 106 91 Stockholm, Sweden
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18
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19
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Jaworski A, Stevensson B, Pahari B, Okhotnikov K, Edén M. Local structures and Al/Si ordering in lanthanum aluminosilicate glasses explored by advanced 27Al NMR experiments and molecular dynamics simulations. Phys Chem Chem Phys 2012; 14:15866-78. [DOI: 10.1039/c2cp42858j] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Brinkmann A, Edén M. Estimating internuclear distances between half-integer quadrupolar nuclei by central-transition double-quantum sideband NMR spectroscopy. CAN J CHEM 2011. [DOI: 10.1139/v11-020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We demonstrate the estimation of homonuclear dipolar couplings, and thereby internuclear distances, between half-integer spin quadrupolar nuclei by central-transition (CT) double-quantum (2Q) sideband nuclear magnetic resonance (NMR) spectroscopy. It is shown that the rotor-encoded sideband amplitudes from CT 2Q coherences in the indirect dimension of the two-dimensional NMR spectrum are sensitive probes of the magnitude of the homonuclear dipolar coupling, but are significantly less affected by other NMR parameters such as the magnitudes and orientations of the electric field gradient tensors. Experimental results of employing the [Formula: see text] recoupling sequence to the 11B spin pair of bis(catecholato)diboron resulted in an estimation of the internuclear B–B distance as (169.6 ± 3) pm, i.e., with a relative uncertainty of ±2%, and in excellent agreement with the distance of 167.8 pm determined by single-crystal X-ray diffraction.
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Affiliation(s)
- Andreas Brinkmann
- Steacie Institute for Molecular Sciences, National Research Council, 1200 Montreal Road, M-40, Ottawa, ON K1A 0R6, Canada
| | - Mattias Edén
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, 106 91 Stockholm, Sweden
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21
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Charpentier T. The PAW/GIPAW approach for computing NMR parameters: a new dimension added to NMR study of solids. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2011; 40:1-20. [PMID: 21612895 DOI: 10.1016/j.ssnmr.2011.04.006] [Citation(s) in RCA: 235] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 04/24/2011] [Accepted: 04/25/2011] [Indexed: 05/18/2023]
Abstract
In 2001, Mauri and Pickard introduced the gauge including projected augmented wave (GIPAW) method that enabled for the first time the calculation of all-electron NMR parameters in solids, i.e. accounting for periodic boundary conditions. The GIPAW method roots in the plane wave pseudopotential formalism of the density functional theory (DFT), and avoids the use of the cluster approximation. This method has undoubtedly revitalized the interest in quantum chemical calculations in the solid-state NMR community. It has quickly evolved and improved so that the calculation of the key components of NMR interactions, namely the shielding and electric field gradient tensors, has now become a routine for most of the common nuclei studied in NMR. Availability of reliable implementations in several software packages (CASTEP, Quantum Espresso, PARATEC) make its usage more and more increasingly popular, maybe indispensable in near future for all material NMR studies. The majority of nuclei of the periodic table have already been investigated by GIPAW, and because of its high accuracy it is quickly becoming an essential tool for interpreting and understanding experimental NMR spectra, providing reliable assignments of the observed resonances to crystallographic sites or enabling a priori prediction of NMR data. The continuous increase of computing power makes ever larger (and thus more realistic) systems amenable to first-principles analysis. In the near future perspectives, as the incorporation of dynamical effects and/or disorder are still at their early developments, these areas will certainly be the prime target.
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Affiliation(s)
- Thibault Charpentier
- CEA, IRAMIS, SIS2M, Laboratoire de Structure et Dynamique par Résonance Magnétique, UMR CEA-CNRS 3299, F-91191 Gif-sur-Yvette cedex, France.
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22
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Iuga D. Double-quantum homonuclear correlations of spin I=5/2 nuclei. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 208:225-34. [PMID: 21145273 DOI: 10.1016/j.jmr.2010.11.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 11/03/2010] [Accepted: 11/10/2010] [Indexed: 05/25/2023]
Abstract
The challenges associated with acquiring double-quantum homonuclear Nuclear Magnetic Resonance correlation spectra of half-integer quadrupolar nuclei are described. In these experiments the radio-frequency irradiation amplitude is necessarily weak in order to selectively excite the central transition. In this limit only one out of the 25 double-quantum coherences possible for two coupled spin I=5/2 nuclei is excited. An investigation of all the 25 two spins double quantum transitions reveals interesting effects such as a compensation of the first-order quadrupolar interaction between the two single quantum transitions involved in the double quantum coherence. In this paper a full numerical study of a hypothetical two spin I=5/2 system is used to show what happens when the RF amplitude during recoupling is increased. In principle this is advantageous, since the required double quantum coherence should build up faster, but in practice it also induces adiabatic passage transfer of population and coherence which impedes any build up. Finally an optimized rotary resonance recoupling (oR(3)) sequence is introduced in order to decrease these transfers. This sequence consists of a spin locking irradiation whose amplitude is reduced four times during one rotor period, and allows higher RF powers to be used during recoupling. The sequence is used to measure (27)Al DQ dipolar correlation spectra of Y(3)Al(5)O(12) (YAG) and gamma alumina (γAl(2)O(3)). The results prove that aluminium vacancies in gamma alumina mainly occur in the tetrahedral sites.
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Affiliation(s)
- Dinu Iuga
- Physics Department, University of Warwick, CV4 7AL Coventry, UK.
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23
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Fernandez C, Pruski M. Probing quadrupolar nuclei by solid-state NMR spectroscopy: recent advances. Top Curr Chem (Cham) 2011; 306:119-88. [PMID: 21656101 DOI: 10.1007/128_2011_141] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Solid-state nuclear magnetic resonance (NMR) of quadrupolar nuclei has recently undergone remarkable development of capabilities for obtaining structural and dynamic information at the molecular level. This review summarizes the key achievements attained during the last couple of decades in solid-state NMR of both integer spin and half-integer spin quadrupolar nuclei. We provide a concise description of the first- and second-order quadrupolar interactions, and their effect on the static and magic angle spinning (MAS) spectra. Methods are explained for efficient excitation of single- and multiple-quantum coherences, and acquisition of spectra under low- and high-resolution conditions. Most of all, we present a coherent, comparative description of the high-resolution methods for half-integer quadrupolar nuclei, including double rotation (DOR), dynamic angle spinning (DAS), multiple-quantum magic angle spinning (MQMAS), and satellite transition magic angle spinning (STMAS). Also highlighted are methods for processing and analysis of the spectra. Finally, we review methods for probing the heteronuclear and homonuclear correlations between the quadrupolar nuclei and their quadrupolar or spin-1/2 neighbors.
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Barrow NS, Yates JR, Feller SA, Holland D, Ashbrook SE, Hodgkinson P, Brown SP. Towards homonuclear J solid-state NMR correlation experiments for half-integer quadrupolar nuclei: experimental and simulated 11B MAS spin-echo dephasing and calculated 2JBB coupling constants for lithium diborate. Phys Chem Chem Phys 2011; 13:5778-89. [DOI: 10.1039/c0cp02343d] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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25
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Lee SK. Effect of pressure on structure of oxide glasses at high pressure: Insights from solid-state NMR of quadrupolar nuclides. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2010; 38:45-57. [PMID: 21074379 DOI: 10.1016/j.ssnmr.2010.10.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 10/15/2010] [Accepted: 10/18/2010] [Indexed: 05/30/2023]
Abstract
Revealing the structure of oxide glasses at high pressure remains a fundamental yet difficult problem in modern physical and chemical sciences. The recent advances in solid-state NMR techniques used for quadrupolar nuclides offer a considerably improved resolution of atomic sites, unveiling previously unknown structural details of oxides glasses at high pressure. Here, we present an overview of the recent progress and insights by high-resolution multi-nuclear triple quantum magic angle spinning (3QMAS) NMR into pressure-induced changes in coordination number, connectivity, and topological disorder in oxide glasses quenched from melts at high pressure. (11)B and (27)Al 3QMAS NMR studies of oxide glasses show that the formation of highly coordinated Al (([5,6])Al) and four coordinated ([4])B are prevalent at high pressure up to 8 GPa. The formation of oxygen clusters linking these highly coordinated framework units and Si (e.g., ([5,6])Al-O-([4])Si, ([5,6])Si-O-([4])Si, and Na-O-([5,6])Si) is observed in the (17)O NMR spectra at higher pressure, leading to an overall increase in the degree of polymerization with pressure. (23)Na MAS NMR spectra of diverse oxide glasses at high pressure and high magnetic field also indicate that the Na-O bond distance may decrease with pressure. Pressure-induced changes in structurally relevant NMR parameters such as the (17)O quadrupolar coupling product (P(q)) for the Si-O-Si cluster and (27)Al P(q) for Al sites in oxide glasses indicate the occurrence of pressure-induced reductions in the Si-O-Si angle and an increase in the Al-O bond length distribution with pressure, indicating an increase in the overall topological disorder in oxide glasses with pressure. All the pressure-induced changes in structure and topology are characterized by strong composition dependence. These experimental results highlight a new opportunity to investigate the molecular structures of silicate melts at high pressure and reveal connections between the microscopic signatures of anomalous and non-linear changes in the macroscopic properties of the corresponding liquids. While many challenges still remain in the synthesis of oxide glasses with wider range of melt composition at higher pressure above 12 GPa, recent progress in enhancement of sensitivity and resolution in the solid state NMR hold strong promise for study exploring additional details of connectivity among quadrupolar nuclides and medium-range order of the more complex, multi-components glasses at high pressure.
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Affiliation(s)
- Sung Keun Lee
- Laboratory of Physics and Chemistry of Earth Materials, School of Earth and Environmental Sciences, Seoul National University, Seoul 151-742, Republic of Korea.
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26
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Hanna JV, Smith ME. Recent technique developments and applications of solid state NMR in characterising inorganic materials. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2010; 38:1-18. [PMID: 20605082 DOI: 10.1016/j.ssnmr.2010.05.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2010] [Revised: 05/29/2010] [Accepted: 05/31/2010] [Indexed: 05/04/2023]
Abstract
A broad overview is given of some key recent developments in solid state NMR techniques that have driven enhanced applications to inorganic materials science. Reference is made to advances in hardware, pulse sequences and associated computational methods (e.g. first principles calculations, spectral simulation), along with their combination to provide more information about solid phases. The resulting methodology has allowed more nuclei to be observed and more structural information to be extracted. Cross referencing between experimental parameters and their calculation from the structure has given an added dimension to NMR as a characterisation probe of materials. Emphasis is placed on the progress made in the last decade especially from those nuclei that were little studied previously. The general points about technique development and the increased range of nuclei observed are illustrated through some specific exemplars from inorganic materials science.
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Affiliation(s)
- J V Hanna
- Department of Physics, University of Warwick, Coventry CV47AL, UK
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27
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Edén M. Two-dimensional MAS NMR correlation protocols involving double-quantum filtering of quadrupolar spin-pairs. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 204:99-110. [PMID: 20202872 DOI: 10.1016/j.jmr.2010.02.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2009] [Revised: 02/07/2010] [Accepted: 02/09/2010] [Indexed: 05/28/2023]
Abstract
Three two-dimensional (2D) NMR homonuclear correlation techniques invoking double-quantum (2Q) filtration of the central transitions of half-integer spins are evaluated numerically and experimentally. They correlate directly detected single-quantum (1Q) coherences in the t(2) domain with either of 1Q, two-spin 2Q or single-spin multiple-quantum coherence-evolutions in the indirect (t(1)) dimension. We employ experimental (23)Na and (27)Al NMR on sodium sulfite and the natural mineral sillimanite (SiAl(2)O(5)), in conjunction with simulated 2D spectra from pairs of dipolar-recoupled spins-3/2 and 5/2 at different external magnetic fields, to compare the correlation strategies from the viewpoints of 2D spectral resolution, signal sensitivity, implementational aspects and their relative merits for establishing internuclear proximities and quadrupolar tensor orientations.
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Affiliation(s)
- Mattias Edén
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden.
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28
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Lee SK, Kim HN, Lee BH, Kim HI, Kim EJ. Nature of Chemical and Topological Disorder in Borogermanate Glasses: Insights from B-11 and O-17 Solid-State NMR and Quantum Chemical Calculations. J Phys Chem B 2009; 114:412-20. [DOI: 10.1021/jp9093113] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sung Keun Lee
- Laboratory of Physics and Chemistry of Earth Materials, School of Earth and Environmental Sciences, Seoul National University, Seoul, 151-742, Korea
| | - Hyun Na Kim
- Laboratory of Physics and Chemistry of Earth Materials, School of Earth and Environmental Sciences, Seoul National University, Seoul, 151-742, Korea
| | - Bum Han Lee
- Laboratory of Physics and Chemistry of Earth Materials, School of Earth and Environmental Sciences, Seoul National University, Seoul, 151-742, Korea
| | - Hyo-Im Kim
- Laboratory of Physics and Chemistry of Earth Materials, School of Earth and Environmental Sciences, Seoul National University, Seoul, 151-742, Korea
| | - Eun Jeong Kim
- Laboratory of Physics and Chemistry of Earth Materials, School of Earth and Environmental Sciences, Seoul National University, Seoul, 151-742, Korea
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29
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Edén M, Lo AYH. Supercycled symmetry-based double-quantum dipolar recoupling of quadrupolar spins in MAS NMR: I. Theory. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2009; 200:267-279. [PMID: 19648039 DOI: 10.1016/j.jmr.2009.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 07/04/2009] [Accepted: 07/08/2009] [Indexed: 05/28/2023]
Abstract
Using average Hamiltonian (AH) theory, we analyze recently introduced homonuclear dipolar recoupling pulse sequences for exciting central-transition double-quantum coherences (2QC) between half-integer spin quadrupolar nuclei undergoing magic-angle-spinning. Several previously observed differences among the recoupling schemes concerning their compensation to resonance offsets and radio-frequency (rf) inhomogeneity may qualitatively be rationalized by an AH analysis up to third perturbation order, despite its omission of first-order quadrupolar interactions. General aspects of the engineering of 2Q-recoupling pulse sequences applicable to half-integer spins are discussed, emphasizing the improvements offered from a diversity of supercycles providing enhanced suppression of undesirable AH cross-terms between resonance offsets and rf amplitude errors.
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Affiliation(s)
- Mattias Edén
- Physical Chemistry Division, Stockholm University, Stockholm, Sweden.
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