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Babenko SV, Sviyazov SV, Burueva DB, Koptyug IV. Hyperpolarized long-lived spin state of methylene protons of 2-bromoethanol obtained from ethylene with non-equilibrium nuclear spin order. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 360:107648. [PMID: 38401476 DOI: 10.1016/j.jmr.2024.107648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 02/05/2024] [Accepted: 02/10/2024] [Indexed: 02/26/2024]
Abstract
In this work we achieve a significant overpopulation (PLLS≈1%) of the long-lived spin state (LLS) of methylene protons in 2-bromoethan(2H)ol (BrEtOD) obtained in a reaction between ethylene with non-equilibrium nuclear spin order and bromine water. Given all protons in ethylene are magnetically equivalent, its nuclear states are classified into nuclear spin isomers (NSIM) with total spin I = 2,1,0. Addition of parahydrogen to acetylene produces ethylene with a population of only those NSIMs with I = 1,0. As a result of the reaction with bromine water the non-equilibrium spin order of ethylene is partly transferred to the singlet LLS involving the two methylene groups of BrEtOD. The 1H NMR signal enhancement (SE≈200) obtained as a result of the LLS readout is approximately equal to the SE of the hyperpolarized BrEtOD obtained with a single π/4 pulse. The LLS relaxation time (TLLS) was shown to be approximately 40 s (≈8T1) in the argon-bubbled sample.
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Affiliation(s)
- Simon V Babenko
- Laboratory of Magnetic Resonance Microimaging, International Tomography Center, SB RAS, Novosibirsk 630090, Russia; V.V. Voevodsky Institute of Chemical Kinetics and Combustion, SB RAS, Novosibirsk 630090, Russia.
| | - Sergey V Sviyazov
- Laboratory of Magnetic Resonance Microimaging, International Tomography Center, SB RAS, Novosibirsk 630090, Russia; Novosibirsk State University, Novosibirsk 630090, Russia
| | - Dudari B Burueva
- Laboratory of Magnetic Resonance Microimaging, International Tomography Center, SB RAS, Novosibirsk 630090, Russia
| | - Igor V Koptyug
- Laboratory of Magnetic Resonance Microimaging, International Tomography Center, SB RAS, Novosibirsk 630090, Russia
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Sviyazov SV, Babenko SV, Skovpin IV, Kovtunova LM, Chukanov NV, Stakheev AY, Burueva DB, Koptyug IV. Manipulating stereoselectivity of parahydrogen addition to acetylene to unravel interconversion of ethylene nuclear spin isomers. Phys Chem Chem Phys 2024; 26:7821-7829. [PMID: 38375632 DOI: 10.1039/d3cp04983c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
Symmetric molecules exist as distinct nuclear spin isomers (NSIMs). A deeper understanding of their properties, including interconversion of different NSIMs, requires efficient techniques for NSIM enrichment. In this work, selective hydrogenation of acetylene with parahydrogen (p-H2) was used to achieve the enrichment of ethylene NSIMs and to study their equilibration processes. The effect of the stereoselectivity of H2 addition to acetylene on the imbalance of ethylene NSIMs was experimentally demonstrated by using three different heterogeneous catalysts (an immobilized Ir complex and two supported Pd catalysts). The interconversion of NSIMs with time during ethylene storage was studied using NMR spectroscopy by reacting ethylene with bromine water, which rendered the p-H2-derived protons in the produced 2-bromoethan(2H)ol (BrEtOD) magnetically inequivalent, thereby revealing the non-equilibrium nuclear spin order of ethylene. A thorough analysis of the shape and transformation of the 1H NMR spectra of hyperpolarized BrEtOD allowed us to reveal the initial distribution of produced ethylene NSIMs and their equilibration processes. Comparison of the results obtained with three different catalysts was key to properly attributing the derived characteristic time constants to different ethylene NSIM interconversion processes: ∼3-6 s for interconversion between NSIMs with the same inversion symmetry (i.e., within g or u manifolds) and ∼1700-2200 s between NSIMs with different inversion symmetries (i.e., between g and u manifolds).
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Affiliation(s)
- Sergey V Sviyazov
- Laboratory of Magnetic Resonance Microimaging, International Tomography Center, SB RAS, Novosibirsk 630090, Russia.
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - Simon V Babenko
- Laboratory of Magnetic Resonance Microimaging, International Tomography Center, SB RAS, Novosibirsk 630090, Russia.
- V.V. Voevodsky Institute of Chemical Kinetics and Combustion, SB RAS, Novosibirsk 630090, Russia
| | - Ivan V Skovpin
- Laboratory of Magnetic Resonance Microimaging, International Tomography Center, SB RAS, Novosibirsk 630090, Russia.
| | - Larisa M Kovtunova
- Laboratory of Magnetic Resonance Microimaging, International Tomography Center, SB RAS, Novosibirsk 630090, Russia.
- Boreskov Institute of Catalysis, SB RAS, Novosibirsk 630090, Russia
| | - Nikita V Chukanov
- Laboratory of Magnetic Resonance Microimaging, International Tomography Center, SB RAS, Novosibirsk 630090, Russia.
- Novosibirsk State University, Novosibirsk 630090, Russia
| | | | - Dudari B Burueva
- Laboratory of Magnetic Resonance Microimaging, International Tomography Center, SB RAS, Novosibirsk 630090, Russia.
| | - Igor V Koptyug
- Laboratory of Magnetic Resonance Microimaging, International Tomography Center, SB RAS, Novosibirsk 630090, Russia.
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Symmetry Constraints on Spin Order Transfer in Parahydrogen-Induced Polarization (PHIP). Symmetry (Basel) 2022. [DOI: 10.3390/sym14030530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
It is well known that the association of parahydrogen (pH2) with an unsaturated molecule or a transient metalorganic complex can enhance the intensity of NMR signals; the effect is known as parahydrogen-induced polarization (PHIP). During recent decades, numerous methods were proposed for converting pH2-derived nuclear spin order to the observable magnetization of protons or other nuclei of interest, usually 13C or 15N. Here, we analyze the constraints imposed by the topological symmetry of the spin systems on the amplitude of transferred polarization. We find that in asymmetric systems, heteronuclei can be polarized to 100%. However, the amplitude drops to 75% in A2BX systems and further to 50% in A3B2X systems. The latter case is of primary importance for biological applications of PHIP using sidearm hydrogenation (PHIP-SAH). If the polarization is transferred to the same type of nuclei, i.e., 1H, symmetry constraints impose significant boundaries on the spin-order distribution. For AB, A2B, A3B, A2B2, AA’(AA’) systems, the maximum average polarization for each spin is 100%, 50%, 33.3%, 25%, and 0, respectively, (where A and B (or A’) came from pH2). Remarkably, if the polarization of all spins in a molecule is summed up, the total polarization grows asymptotically with ~1.27 and can exceed 2 in the absence of symmetry constraints (where is the number of spins). We also discuss the effect of dipole–dipole-induced pH2 spin-order distribution in heterogeneous catalysis or nematic liquid crystals. Practical examples from the literature illustrate our theoretical analysis.
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Orr BJ. Collision-induced rovibrational energy transfer in small polyatomic molecules: the role of intramolecular perturbations. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1490463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Brian J. Orr
- Department of Physics and Astronomy, MQ Photonics Research Centre, Macquarie University, Sydney, Australia
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Grohmann T, Haase D, Jia D, Manz J, Yang Y. Nuclear spin blockade of laser ignition of intramolecular rotation in the model boron rotor B 13 + 11 . J Chem Phys 2018; 149:184302. [PMID: 30441922 DOI: 10.1063/1.5048358] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The boron rotor B 13 + 11 consists of a tri-atomic inner "wheel" that may rotate in its pseudo-rotating ten-atomic outer "bearing"-this concerted motion is called "contorsion." B 13 + 11 in its ground state has zero contorsional angular momentum. Starting from this initial state, it is a challenge to ignite contorsion by a laser pulse. We discover, however, that this is impossible, i.e., one cannot design any laser pulse that induces a transition from the ground to excited states with non-zero contorsional angular momentum. The reason is that the ground state is characterized by a specific combination of irreducible representations (IRREPs) of its contorsional and nuclear spin wavefunctions. Laser pulses conserve these IRREPs because hypothetical changes of the IRREPs would require nuclear spin flips that cannot be realized during the interaction with the laser pulse. We show that all excited target states of B 13 + 11 with non-zero contorsional angular momentum have different IRREPs that are inaccessible by laser pulses. Conservation of nuclear spins thus prohibits laser-induced transitions from the non-rotating ground to rotating target states. We discover various additional constraints imposed by conservation of nuclear spins, e.g., laser pulses can change clockwise to counter-clockwise contorsions or vice versa, but they cannot stop them. The results are derived in the frame of a simple model.
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Affiliation(s)
- Thomas Grohmann
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, 92, Wucheng Road, Taiyuan 030006, China
| | - Dietrich Haase
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany
| | - Dongming Jia
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, 92, Wucheng Road, Taiyuan 030006, China
| | - Jörn Manz
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, 92, Wucheng Road, Taiyuan 030006, China
| | - Yonggang Yang
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, 92, Wucheng Road, Taiyuan 030006, China
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Cacciani P, Cosléou J, Khelkhal M, Čermák P, Puzzarini C. Nuclear Spin Conversion in CH4: A Multichannel Relaxation Mechanism. J Phys Chem A 2016; 120:173-82. [PMID: 26681482 DOI: 10.1021/acs.jpca.5b09454] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Experiments on nuclear spin interconversion of ortho, para, and meta nuclear spin isomers of the methane molecule have been undertaken in gas phase and cryomatrices. Only the latter environment has led to the observation of the nuclear spin conversion. In this study, a quantitative explanation is given for the first time by considering the coupling of three relaxation paths: meta ⇔ para, meta ⇔ ortho, and ortho ⇔ para. The global evolution of the three populations of spin isomers is thus described by two characteristic times, which have been calculated using the best values of the energy levels for the vibrational ground state, of the intramolecular magnetic interactions, and of the collisional relaxation rates, and for different pressure and temperature conditions. Such calculations also provide an indication for the proper choice of reliable scenarios for experimental separation of the spin isomers of methane.
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Affiliation(s)
- Patrice Cacciani
- Univ. Lille , CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
| | - Jean Cosléou
- Univ. Lille , CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
| | - Mohamed Khelkhal
- Univ. Lille , CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
| | - Peter Čermák
- Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University , Mlynská dolina, 842 48 Bratislava, Slovakia
| | - Cristina Puzzarini
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna , via Selmi 2, 40126 Bologna, Italy
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Mamone S, Concistrè M, Carignani E, Meier B, Krachmalnicoff A, Johannessen OG, Lei X, Li Y, Denning M, Carravetta M, Goh K, Horsewill AJ, Whitby RJ, Levitt MH. Nuclear spin conversion of water inside fullerene cages detected by low-temperature nuclear magnetic resonance. J Chem Phys 2014; 140:194306. [PMID: 24852537 DOI: 10.1063/1.4873343] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The water-endofullerene H2O@C60 provides a unique chemical system in which freely rotating water molecules are confined inside homogeneous and symmetrical carbon cages. The spin conversion between the ortho and para species of the endohedral H2O was studied in the solid phase by low-temperature nuclear magnetic resonance. The experimental data are consistent with a second-order kinetics, indicating a bimolecular spin conversion process. Numerical simulations suggest the simultaneous presence of a spin diffusion process allowing neighbouring ortho and para molecules to exchange their angular momenta. Cross-polarization experiments found no evidence that the spin conversion of the endohedral H2O molecules is catalysed by (13)C nuclei present in the cages.
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Affiliation(s)
- Salvatore Mamone
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Maria Concistrè
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Elisa Carignani
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Benno Meier
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Andrea Krachmalnicoff
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Ole G Johannessen
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Xuegong Lei
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Yongjun Li
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Mark Denning
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Marina Carravetta
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Kelvin Goh
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Anthony J Horsewill
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Richard J Whitby
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Malcolm H Levitt
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
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Zhivonitko VV, Kovtunov KV, Chapovsky PL, Koptyug IV. Nuclear Spin Isomers of Ethylene: Enrichment by Chemical Synthesis and Application for NMR Signal Enhancement. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201307389] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Zhivonitko VV, Kovtunov KV, Chapovsky PL, Koptyug IV. Nuclear Spin Isomers of Ethylene: Enrichment by Chemical Synthesis and Application for NMR Signal Enhancement. Angew Chem Int Ed Engl 2013; 52:13251-5. [DOI: 10.1002/anie.201307389] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Indexed: 11/07/2022]
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