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Jackowski K, Wilczek M. Measurements of Nuclear Magnetic Shielding in Molecules. Molecules 2024; 29:2617. [PMID: 38893492 PMCID: PMC11173999 DOI: 10.3390/molecules29112617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 05/24/2024] [Accepted: 05/30/2024] [Indexed: 06/21/2024] Open
Abstract
The origin of nuclear magnetic shielding in diamagnetic molecules is discussed, pointing out various contributions to the shielding from electrons and the effects of intra- and intermolecular interactions. In NMR practice, chemical shifts are determined first as the measure of shielding in observed samples. The descriptions of shielding and chemical shifts are not fully consistent. Gas phase studies permit the withdrawal of intermolecular contributions from shielding and obtaining the magnetic shielding data in isolated molecules. The shielding determination in molecules is possible using at least three methods delivering the reference shielding standards for selected nuclei. The known shielding of one magnetic nucleus can be transferred to other nuclei if the appropriate nuclear magnetic moments are available with satisfactory accuracy. It is possible to determine the nuclear magnetic dipole moments using the most advanced ab initio shielding calculations jointly with the NMR frequencies measurements for small-sized isolated molecules. Helium-3 gas is postulated as all the molecules' primary and universal reference standard of shielding. It can be easily applied using common deuterium lock solvents as the secondary reference standards. The measurements of absolute shielding are available for everyone with the use of standard NMR spectrometers.
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Affiliation(s)
- Karol Jackowski
- Laboratory of NMR Spectroscopy, Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland;
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Duchowny A, Ortiz Restrepo SA, Adams M, Thelen R, Adams A. Refined high-pressure tube design for improved resolution in high-pressure NMR spectroscopy. Analyst 2022; 147:3827-3832. [DOI: 10.1039/d2an00926a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple, low-cost, and easy-to-replicate high-pressure sapphire tube for NMR spectroscopy experiments is introduced. The significant improvement in spectral resolution enables, e.g., in situ quantification of the H2 ingress in green solvents.
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Affiliation(s)
- Anton Duchowny
- Institut für Technische und Makromolekulare Chemie, RWTH Aachen University, Templergraben 55, 52056 Aachen, Germany
| | | | - Michael Adams
- Institut für Technische und Makromolekulare Chemie, RWTH Aachen University, Templergraben 55, 52056 Aachen, Germany
| | - Ralf Thelen
- Institut für Technische und Makromolekulare Chemie, RWTH Aachen University, Templergraben 55, 52056 Aachen, Germany
| | - Alina Adams
- Institut für Technische und Makromolekulare Chemie, RWTH Aachen University, Templergraben 55, 52056 Aachen, Germany
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Garbacz P, Misiak M, Jackowski K. NMR shielding in helium-3 atoms modified by gaseous nitrogen and oxygen. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2020; 58:745-749. [PMID: 32293746 DOI: 10.1002/mrc.5030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 06/11/2023]
Abstract
Helium-3 nuclear magnetic resonance (3 He NMR) measurements were carried out for the gaseous mixtures of helium-3 with pure nitrogen and synthetic air as the solvents. It was found that 3 He shielding is linearly dependent on solvent density up to approx. 6 mol/L. At higher density of the gaseous solvent, the change of 3 He shielding is nonlinear and especially distinct when helium-3 atoms can interact with two O2 molecules. The interaction with paramagnetic oxygen molecules can induce two kinds of 3 He shielding changes: (1) due to the isotropic Fermi contact interaction and (2) from the dipolar magnetic interaction between unpaired O2 electrons and 3 He nuclear magnetic dipole moment. The two paramagnetic effects in helium-3 shielding cannot be experimentally separated, although for such small molecular objects, they could be presumably modeled by advanced theoretical calculations.
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Affiliation(s)
- Piotr Garbacz
- Laboratory of NMR Spectroscopy, Faculty of Chemistry, University of Warsaw, Warsaw, Poland
| | - Maria Misiak
- Laboratory of NMR Spectroscopy, Faculty of Chemistry, University of Warsaw, Warsaw, Poland
| | - Karol Jackowski
- Laboratory of NMR Spectroscopy, Faculty of Chemistry, University of Warsaw, Warsaw, Poland
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Makulski W, Wilczek M, Jackowski K. 17O and 1H NMR spectral parameters in isolated water molecules. Phys Chem Chem Phys 2018; 20:22468-22476. [PMID: 30137101 DOI: 10.1039/c8cp01748d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Small amounts of water enriched in oxygen-17 were studied by 17O and 1H NMR in binary gaseous mixtures with Xe, Kr, CHF3 and CH3F and CO2. The distinct linear dependences of 17O and 1H chemical shifts and 1J(17O,1H) spin-spin coupling on the density of every gas solvent were measured. After the extrapolation of experimental results to zero density the relevant parameters in the isolated H217O molecule were determined. The same procedure was applied for H216O when its proton chemical shift was analyzed but the secondary isotope effect in the 1H shielding of H217O and H216O molecules was too small for detection. As shown, all the intermolecular effects in nuclear magnetic shielding are negative and these effects are more significant for 17O nuclei than for protons. It is consistent with the appropriate gas-to-liquid shifts of water which also indicate deshielding effects for both the investigated nuclei. On the other hand, the 1J0(17O,1H) coupling constant in H217O, which is completely free from intermolecular interactions, considerably differs from the 1J(17O,1H) experimental values obtained for water in liquid solutions. The present experimental data of the isolated H217O molecule are compared with selected results of shielding and spin-spin coupling calculations available from the literature and with the recent experimental data for a water molecule encapsulated in the C60 fullerene. Additionally, on the basis of actual results the magnetic dipole moment of the 17O nucleus is revalued for greater accuracy.
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Affiliation(s)
- Włodzimierz Makulski
- Laboratory of NMR Spectroscopy, Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warszawa, Poland.
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Garbacz P. Spin–spin coupling in the HD molecule determined from 1H and 2H NMR experiments in the gas-phase. Chem Phys 2014. [DOI: 10.1016/j.chemphys.2014.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Makulski W. (83)Kr nuclear magnetic moment in terms of that of (3)He. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2014; 52:430-434. [PMID: 24842240 DOI: 10.1002/mrc.4083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 03/12/2014] [Accepted: 04/23/2014] [Indexed: 06/03/2023]
Abstract
High resolution NMR spectroscopy was applied to precisely determine the (83)Kr nuclear magnetic dipole moment on the basis of new results available for nuclear magnetic shielding in krypton and helium-3 atoms. Small amounts of (3)He as the solutes and (83)Kr as the buffer gas were observed in (3)He and (83)Kr NMR spectra at the constant external field, B0 = 11.7578 T. In each case, the resonance frequencies (ν(He) and ν(Kr)) were linearly dependent on the density of gaseous solvent. The extrapolation of experimental points to the zero density of gaseous krypton allowed for the evaluation of both resonance frequencies free from intermolecular interactions. By combining these measurements with the recommended (83)Kr chemical shielding value, the nuclear magnetic moment could be determined with much better precision than ever before, μ((83)Kr) = -0.9707297(32)μN, with the improvement due to the greater accuracy of the spectral data.
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Affiliation(s)
- Włodzimierz Makulski
- Laboratory of NMR Spectroscopy, Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warszawa, Poland
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Jaszuński M, Repisky M, Demissie TB, Komorovsky S, Malkin E, Ruud K, Garbacz P, Jackowski K, Makulski W. Spin-rotation and NMR shielding constants in HCl. J Chem Phys 2013; 139:234302. [DOI: 10.1063/1.4840295] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Skomorowski W, Moszynski R. Kerr and Cotton–Mouton effects in atomic gases: a quantum-statistical study. Mol Phys 2013. [DOI: 10.1080/00268976.2013.804959] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Wojciech Skomorowski
- a Faculty of Chemistry , University of Warsaw , Pasteura 1, Warsaw , 02-093 , Poland
| | - Robert Moszynski
- a Faculty of Chemistry , University of Warsaw , Pasteura 1, Warsaw , 02-093 , Poland
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Garbacz P, Jackowski K, Makulski W, Wasylishen RE. Nuclear Magnetic Shielding for Hydrogen in Selected Isolated Molecules. J Phys Chem A 2012; 116:11896-904. [DOI: 10.1021/jp309820v] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Piotr Garbacz
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warszawa,
Poland
| | - Karol Jackowski
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warszawa,
Poland
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Jaszuński M, Antušek A, Garbacz P, Jackowski K, Makulski W, Wilczek M. The determination of accurate nuclear magnetic dipole moments and direct measurement of NMR shielding constants. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2012; 67:49-63. [PMID: 23101589 DOI: 10.1016/j.pnmrs.2012.03.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 03/08/2012] [Indexed: 06/01/2023]
Affiliation(s)
- Michał Jaszuński
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw, Poland.
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Helgaker T, Jaszuński M, Garbacz P, Jackowski K. The NMR indirect nuclear spin–spin coupling constant of the HD molecule. Mol Phys 2012. [DOI: 10.1080/00268976.2012.729097] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Trygve Helgaker
- a Centre for Theoretical and Computational Chemistry, Department of Chemistry , University of Oslo , P.O.B. 1033 Blindern, N-0315 Oslo , Norway
| | - Michał Jaszuński
- b Institute of Organic Chemistry, Polish Academy of Sciences , Kasprzaka 44, 01224 Warsaw , Poland
| | - Piotr Garbacz
- c Laboratory of NMR Spectroscopy, Department of Chemistry , University of Warsaw , Pasteura 1, 02-093 Warsaw , Poland
| | - Karol Jackowski
- c Laboratory of NMR Spectroscopy, Department of Chemistry , University of Warsaw , Pasteura 1, 02-093 Warsaw , Poland
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