What Most Affects the Accuracy of <sup>125</sup>Te NMR Chemical Shift Calculations

Rusakov, Yury Yu.; Rusakova, Irina L.

doi:10.1021/acs.jpca.0c05780

Cited by 11 publications

(9 citation statements)

References 130 publications

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“…This issue of relativistic effects is an important one, especially for the fourth-row atoms I, Te, and Sb. − It is not only the effects on the atoms themselves , but also the interplay between these heavy atoms and their surrounding light atoms, the so-called HALA effect . As an example, a very recent study noted that relativity can account for perhaps some 25–35% of the chemical shielding of Te. As recently summarized nicely in a review article, these effects can be defined and approximated in various ways, for example, by variational or perturbational inclusion of spin–orbit coupling and scalar relativistic effects.…”

Section: Discussionmentioning

confidence: 99%

Relationships between Bond Strength and Spectroscopic Quantities in H-Bonds and Related Halogen, Chalcogen, and Pnicogen Bonds

Scheiner

2020

J. Phys. Chem. A

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A large number of systems were studied that contain either a H-bond (HB) or the closely related halogen (X), chalcogen (Y), or pnicogen (Z) bond. Many of the same relationships between the strength of the HB and spectroscopic parameters apply as well to the other noncovalent bonds. There is a very nearly linear relationship between the interaction energy and the red shift that occurs within the stretching frequency of the pertinent F−A covalent bond of the Lewis acid (where A refers to H, X, Y, or Z). This vibrational mode also undergoes an intensification in all of these bond types, but this quantity is slightly less indicative of the bond strength for XB, YB, and ZB than it is for HB. On the other hand, most of the various noncovalent bonds display a better relationship between energetics and NMR chemical shifts than do the Hbonds, highly auspicious for the use of NMR spectra in diagnosing the presence and strengths of these bonds. An important element in NMR chemical shifts is the internal geometry change induced by complexation.

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Section: Discussionmentioning

confidence: 99%

Relationships between Bond Strength and Spectroscopic Quantities in H-Bonds and Related Halogen, Chalcogen, and Pnicogen Bonds

Scheiner

2020

J. Phys. Chem. A

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“…We have chosen this function based on two prerequisites. The strongest argument was based on an observation that we made in one of our previous papers [ 105 ]. Namely, it was shown that the SVWN5 functional provides the best description of the relativistic effects on tellurium NMR chemical shifts, in spite of the fact that it has been designed neither for the relativistic effects nor for the NMR shielding constants.…”

Section: Resultsmentioning

confidence: 99%

On the Utmost Importance of the Basis Set Choice for the Calculations of the Relativistic Corrections to NMR Shielding Constants

Rusakova

Rusakov

2023

IJMS

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The investigation of the sensitivity of the relativistic corrections to the NMR shielding constants (σ) to the configuration of angular spaces of the basis sets used on the atoms of interest was carried out within the four-component density functional theory (DFT). Both types of relativistic effects were considered, namely the so-called heavy atom on light atom and heavy atom on heavy atom effects, though the main attention was paid to the former. As a main result, it was found that the dependence of the relativistic corrections to σ of light nuclei (exemplified here by 1H and 13C) located in close vicinity to a heavy atom (exemplified here by In, Sn, Sb, Te, and I) on the basis set used on the light spectator atom was very much in common with that of the Fermi-contact contribution to the corresponding nonrelativistic spin-spin coupling constant (J). In general, it has been shown that the nonrelativistic J-oriented and σ-oriented basis sets, artificially saturated in the tight s-region, provided much better accuracy than the standard nonrelativistic σ-oriented basis sets when calculating the relativistic corrections to the NMR shielding constants of light nuclei at the relativistic four-component level of the DFT theory.

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“…The total values of nitrogen chemical shifts δ tot in Table 1 were calculated using the linear regression analysis [ 63 , 64 , 65 ]. The strategy of this approach consists of the mapping of the observed chemical shifts onto the predicted shielding constants, in which the relationship is simulated by the linear model: σ = Aδ + B …”

Section: Resultsmentioning

confidence: 99%

Four-Component Relativistic Calculations of NMR Shielding Constants of the Transition Metal Complexes—Part 2: Nitrogen-Coordinated Complexes of Cobalt

Samultsev

Semenov

Rusakova

et al. 2022

IJMS

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Both four-component relativistic and nonrelativistic computations within the GIAO-DFT(PBE0) formalism have been carried out for 15N and 59Co NMR shielding constants and chemical shifts of a number of the nitrogen-coordinated complexes of cobalt. It was found that the total values of the calculated nitrogen chemical shifts of considered cobalt complexes span over a range of more than 580 ppm, varying from −452 to +136 ppm. At that, the relativistic corrections to nitrogen shielding constants and chemical shifts were demonstrated to be substantial, changing accordingly from ca. −19 to +74 ppm and from −68 to +25 ppm. Solvent effects on 15N shielding constants and chemical shifts were shown to have contributions no less important than the relativistic effects, namely from −35 to +63 ppm and from −74 to +23 ppm, respectively. Cobalt shielding constants and chemical shifts were found to vary in the ranges of, accordingly, −20,157 to −11,373 ppm and from +3781 to +13,811. The relativistic effects are of major importance in the cobalt shielding constants, resulting in about 4% for the shielding-type contributions, while solvent corrections to cobalt shielding constants appeared to be of less significance, providing corrections of about 1.4% to the gas phase values.

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What Most Affects the Accuracy of ¹²⁵Te NMR Chemical Shift Calculations

Cited by 11 publications

References 130 publications

Relationships between Bond Strength and Spectroscopic Quantities in H-Bonds and Related Halogen, Chalcogen, and Pnicogen Bonds

Relationships between Bond Strength and Spectroscopic Quantities in H-Bonds and Related Halogen, Chalcogen, and Pnicogen Bonds

On the Utmost Importance of the Basis Set Choice for the Calculations of the Relativistic Corrections to NMR Shielding Constants

Four-Component Relativistic Calculations of NMR Shielding Constants of the Transition Metal Complexes—Part 2: Nitrogen-Coordinated Complexes of Cobalt

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What Most Affects the Accuracy of 125Te NMR Chemical Shift Calculations

Cited by 11 publications

References 130 publications

Relationships between Bond Strength and Spectroscopic Quantities in H-Bonds and Related Halogen, Chalcogen, and Pnicogen Bonds

Relationships between Bond Strength and Spectroscopic Quantities in H-Bonds and Related Halogen, Chalcogen, and Pnicogen Bonds

On the Utmost Importance of the Basis Set Choice for the Calculations of the Relativistic Corrections to NMR Shielding Constants

Four-Component Relativistic Calculations of NMR Shielding Constants of the Transition Metal Complexes—Part 2: Nitrogen-Coordinated Complexes of Cobalt

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What Most Affects the Accuracy of ¹²⁵Te NMR Chemical Shift Calculations