The Calcium Carbonate Geological Samples Study by 3He NMR

Alakshin, E. M.; Gazizulin, R. R.; Klochkov, A. V.; Kondratyeva, E. I.; Laskin, Artem; Tagirov, M. S.

doi:10.1007/s00723-017-0904-y

Cited by 4 publications

(6 citation statements)

References 24 publications

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“…The first contribution could be evaluated by computing the NICS values (the property describing the chemical shift of a virtual nucleus without charge and electrons, which is placed at a given point). NICS calculations were first introduced in ref and later used, for example, for studying the aromaticity and proton shielding/deshielding upon approaching to proton acceptor sites . We have plotted maps of the δ He –NICS values, which was expected to reflect the part of shielding exclusively due to the interactions of the electronic shells of a helium atom and a studied species (see Figures S7 and S8 in Supporting Information).…”

Section: Resultsmentioning

confidence: 99%

“…For further details about the calculation of electron density, Laplacian of electron density, nuclear independent chemical shift (NICS , ), and gradient of helium chemical shift ∇δ He , see the Supporting Information.…”

Section: Computational Detailsmentioning

confidence: 99%

“…In ref , helium atom 3 He was considered as a probe, whose NMR chemical shift, δ He , and interaction energy with investigated molecules (fullerenes, nanotubes, and graphene) were used to describe their electronic features. The δ He for helium atoms encapsulated into fullerene cages was also measured experimentally. , Besides, the experimental relaxation characteristics of 3 He interacting with the surfaces of such nanostructures as aerogel, PrF 3 nanoparticles, and geological samples of calcium carbonate were measured.…”

Section: Introductionmentioning

confidence: 99%

“…The δ He for helium atoms encapsulated into fullerene cages was also measured experimentally. 40,41 Besides, the experimental relaxation characteristics of 3 He interacting with the surfaces of such nanostructures as aerogel, 42 PrF 3 nanoparticles, 43 and geological samples of calcium carbonate 44 were measured.…”

Section: ■ Introductionmentioning

confidence: 99%

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NMR Chemical Shift of a Helium Atom as a Probe for Electronic Structure of FH, F^–, (FHF)⁻, and FH₂⁺

et al. 2017

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In this work, we present the first results of outer electronic shell visualization by using a He atom as a probe particle. As model objects we have chosen F, FH, and FH species, as well as the hydrogen-bonded complex FH···F at various H···F distances (3.0, 2.5, 2.0, and 1.5 Å and equilibrium at ca. 1.14 Å). The interaction energy of investigated objects with helium atom (CCSD/aug-cc-pVTZ) and helium atom chemical shift (B3LYP/pcS-2) surfaces were calculated, and their topological analysis was performed. For comparison, the results of standard quantum mechanical approaches to electronic shell visualization were presented (ESP, ELF, ED, ∇ED). We show that the Laplacian of helium chemical shift, ∇δ, is sensitive to fluorine atom lone pair localization regions, and it can be used for the visualization of the outer electronic shell, which could be used to evaluate the proton accepting ability. The sensitivity of ∇δ to lone pairs is preserved at distances as large as 2.0-2.5 Å from the fluorine nucleus (in comparison with the distance to ESP minima, located at 1.0-1.5 Å or maxima of ELF, which are as close as 0.6 Å to the fluorine nucleus).

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Section: Resultsmentioning

confidence: 99%

Section: Computational Detailsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

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NMR Chemical Shift of a Helium Atom as a Probe for Electronic Structure of FH, F^–, (FHF)⁻, and FH₂⁺

et al. 2017

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“… 3 He nucleus was used for investigation of carbon systems (fullerenes, nanotubes, graphene). Furthermore, the surface characteristics of aerogel, PrF 3 nanoparticles, and geological samples of calcium carbonate, were studied by relaxation properties of 3 He. In MRI, hyperpolarized 3 He is employed for visualization of details of pulmonary, alveolar, and blood circulation systems …”

Section: Introductionmentioning

confidence: 99%

Outer electronic shell visualization by NMR chemical shift laplacian of a helium probe

et al. 2018

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A new method of visualization of lone pairs is proposed using fluorine atoms in fluoroacetylene, trifluoroethylene, and fluoroform (sp, sp 2 , and sp 3 hybridized carbons) as an example. The space around fluorines was probed by a helium atom and at each point 3 He NMR chemical shift δ He and its Laplacian r 2 δ He were calculated. The r 2 δ He isosurfaces have symmetrical toroidal shapes along CF axes; the maximum values of r 2 δ He are reached at about 1.5 Å from fluorine atom center in the direction roughly coinciding with the lone pair localization. The absolute values of the r 2 δ He could be used to quantify the electron-rich regions of lone pairs. The results are compared with more common visualization methods-3D maps of the molecular electrostatic potential and the electron localization function. We show that a helium atom could be used for evaluation of fine features of molecular electronic shell, since 3 He NMR spectral characteristics remain sensitive at relatively large distances.

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Determination of pores properties in rocks by means of helium-3 NMR: A case study of oil-bearing arkosic conglomerate from North belt of crude oil, Republic of Cuba

Safiullin

Kuzmin

Bogaychuk

et al. 2022

Journal of Petroleum Science and Engineering

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The Calcium Carbonate Geological Samples Study by 3He NMR

Cited by 4 publications

References 24 publications

NMR Chemical Shift of a Helium Atom as a Probe for Electronic Structure of FH, F^–, (FHF)⁻, and FH₂⁺

NMR Chemical Shift of a Helium Atom as a Probe for Electronic Structure of FH, F^–, (FHF)⁻, and FH₂⁺

Outer electronic shell visualization by NMR chemical shift laplacian of a helium probe

Determination of pores properties in rocks by means of helium-3 NMR: A case study of oil-bearing arkosic conglomerate from North belt of crude oil, Republic of Cuba

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The Calcium Carbonate Geological Samples Study by 3He NMR

Cited by 4 publications

References 24 publications

NMR Chemical Shift of a Helium Atom as a Probe for Electronic Structure of FH, F–, (FHF)−, and FH2+

NMR Chemical Shift of a Helium Atom as a Probe for Electronic Structure of FH, F–, (FHF)−, and FH2+

Outer electronic shell visualization by NMR chemical shift laplacian of a helium probe

Determination of pores properties in rocks by means of helium-3 NMR: A case study of oil-bearing arkosic conglomerate from North belt of crude oil, Republic of Cuba

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NMR Chemical Shift of a Helium Atom as a Probe for Electronic Structure of FH, F^–, (FHF)⁻, and FH₂⁺

NMR Chemical Shift of a Helium Atom as a Probe for Electronic Structure of FH, F^–, (FHF)⁻, and FH₂⁺