Experimental and Theoretical Evidence of Spin‐Orbit Heavy Atom on the Light Atom <sup>1</sup>H NMR Chemical Shifts Induced through H⋅⋅⋅I<sup>−</sup> Hydrogen Bond

Vı́cha, Jan; Růžičková, Zdeňka; Самсонов, М. А.; Bártová, Kateřina; Růžička, Aleš; Straka, Michal; Dračínský, Martin

doi:10.1002/chem.202001532

Cited by 9 publications

(3 citation statements)

References 48 publications

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“…During the revision of this review, solid-state 1 H NMR and DFT study of a series of 4-(dimethylamino)pyridinium with Cl, Br, and I counteranions has been reported . Discrepancy between the experimental and theoretical NMR shifts was attributed to an absence of the SO effects in the calculations of hydrogen-bonded ion pairs at the SR DFT level.…”

Section: Trends In So-hala Shifts Across the Periodic Tablementioning

confidence: 99%

Relativistic Heavy-Neighbor-Atom Effects on NMR Shifts: Concepts and Trends Across the Periodic Table

et al. 2020

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Chemical shifts present crucial information about an NMR spectrum. They show the influence of the chemical environment on the nuclei being probed. Relativistic effects caused by the presence of an atom of a heavy element in a compound can appreciably, even drastically, alter the NMR shifts of the nearby nuclei. A fundamental understanding of such relativistic effects on NMR shifts is important in many branches of chemical and physical science. This review provides a comprehensive overview of the tools, concepts, and periodic trends pertaining to the shielding effects by a neighboring heavy atom in diamagnetic systems, with particular emphasis on the "spin-orbit heavy-atom effect on the light-atom" NMR shift (SO-HALA effect). The analyses and tools described in this review provide guidelines to help NMR spectroscopists and computational chemists estimate the ranges of the NMR shifts for an unknown compound, identify intermediates in catalytic and other processes, analyze conformational aspects and intermolecular interactions, and predict trends in series of compounds throughout the Periodic Table . The present review provides a current snapshot of this important subfield of NMR spectroscopy and a basis and framework for including future findings in the field.

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Section: Trends In So-hala Shifts Across the Periodic Tablementioning

confidence: 99%

Relativistic Heavy-Neighbor-Atom Effects on NMR Shifts: Concepts and Trends Across the Periodic Table

et al. 2020

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“…The electrons in the heavy iodine atom experience severe relativistic effects, and furthermore, halogens that are close to the nucleus of interest are known to increase the s -character of bonding orbitals of the respective nucleus thus evoking strong spin–orbit coupling effects. ,, This influence is generally known as heavy neighbor atom (HNA) effect. − To allow for an unbiased statistical evaluation, these cases (outliers) are excluded from the statistics for SR approaches. The importance of explicit inclusion of spin–orbit effects for these compounds is demonstrated upon application of the SO-ZORA Hamiltonian (Figure c).…”

Section: Resultsmentioning

confidence: 99%

Benchmark Study on the Calculation of ¹¹⁹Sn NMR Chemical Shifts

et al. 2022

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A new benchmark set termed SnS51 for assessing quantum chemical methods for the computation of 119Sn NMR chemical shifts is presented. It covers 51 unique 119Sn NMR chemical shifts for a selection of 50 tin compounds with diverse bonding motifs and ligands. The experimental reference data are in the spectral range of ±2500 ppm measured in seven different solvents. Fifteen common density functional approximations, two scalar- and one spin–orbit relativistic approach are assessed based on conformer ensembles generated using the CREST/CENSO scheme and state-of-the-art semiempirical (GFN2-xTB), force field (GFN-FF), and composite DFT methods (r2SCAN-3c). Based on the results of this study, the spin–orbit relativistic method combinations of SO-ZORA with PBE0 or revPBE functionals are generally recommended. Both yield mean absolute deviations from experimental data below 100 ppm and excellent linear regression determination coefficients of ≤0.99. If spin–orbit calculations are not affordable, the use of SR-ZORA with B3LYP or X2C with ωB97X or M06 may be considered to obtain qualitative predictions if no severe spin–orbit effects, for example, due to heavy nuclei containing ligands, are expected. An empirical linear scaling correction is demonstrated to be applicable for further improvement, and respective empirical parameters are given. Conformational effects on chemical shifts are studied in detail but are mostly found to be small. However, in specific cases when the ligand sphere differs substantially between conformers, chemical shifts can change by up to several hundred ppm.

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“…For instance, even such a light element like sulfur can induce an overall SO‐HALA shielding of −8 ppm at the bound 13 C nuclei . It has also been demonstrated that the SO‐HALA effect can be transmitted through hydrogen bonds …”

Section: Resultsmentioning

confidence: 99%

Towards Accurate Predictions of Proton NMR Spectroscopic Parameters in Molecular Solids

et al. 2020

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The factors contributing to the accuracy of quantum‐chemical calculations for the prediction of proton NMR chemical shifts in molecular solids are systematically investigated. Proton chemical shifts of six solid amino acids with hydrogen atoms in various bonding environments (CH, CH2, CH3, OH, SH and NH3) were determined experimentally using ultra‐fast magic‐angle spinning and proton‐detected 2D NMR experiments. The standard DFT method commonly used for the calculations of NMR parameters of solids is shown to provide chemical shifts that deviate from experiment by up to 1.5 ppm. The effects of the computational level (hybrid DFT functional, coupled‐cluster calculation, inclusion of relativistic spin‐orbit coupling) are thoroughly discussed. The effect of molecular dynamics and nuclear quantum effects are investigated using path‐integral molecular dynamics (PIMD) simulations. It is demonstrated that the accuracy of the calculated proton chemical shifts is significantly better when these effects are included in the calculations.

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Experimental and Theoretical Evidence of Spin‐Orbit Heavy Atom on the Light Atom ¹H NMR Chemical Shifts Induced through H⋅⋅⋅I⁻ Hydrogen Bond

Cited by 9 publications

References 48 publications

Relativistic Heavy-Neighbor-Atom Effects on NMR Shifts: Concepts and Trends Across the Periodic Table

Relativistic Heavy-Neighbor-Atom Effects on NMR Shifts: Concepts and Trends Across the Periodic Table

Benchmark Study on the Calculation of ¹¹⁹Sn NMR Chemical Shifts

Towards Accurate Predictions of Proton NMR Spectroscopic Parameters in Molecular Solids

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Experimental and Theoretical Evidence of Spin‐Orbit Heavy Atom on the Light Atom 1H NMR Chemical Shifts Induced through H⋅⋅⋅I− Hydrogen Bond

Cited by 9 publications

References 48 publications

Relativistic Heavy-Neighbor-Atom Effects on NMR Shifts: Concepts and Trends Across the Periodic Table

Relativistic Heavy-Neighbor-Atom Effects on NMR Shifts: Concepts and Trends Across the Periodic Table

Benchmark Study on the Calculation of 119Sn NMR Chemical Shifts

Towards Accurate Predictions of Proton NMR Spectroscopic Parameters in Molecular Solids

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Product

Resources

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Experimental and Theoretical Evidence of Spin‐Orbit Heavy Atom on the Light Atom ¹H NMR Chemical Shifts Induced through H⋅⋅⋅I⁻ Hydrogen Bond

Benchmark Study on the Calculation of ¹¹⁹Sn NMR Chemical Shifts