On the Geometry Dependence of the NMR Chemical Shift of Mercury in Thiolate Complexes: A Relativistic DFT Study
Research output: Working paper › Preprint › Research
Standard
On the Geometry Dependence of the NMR Chemical Shift of Mercury in Thiolate Complexes: A Relativistic DFT Study. / Wu, Haide; Hemmingsen, Lars Bo Stegeager; Sauer, Stephan P. A.
arxiv.org, 2023.Research output: Working paper › Preprint › Research
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - UNPB
T1 - On the Geometry Dependence of the NMR Chemical Shift of Mercury in Thiolate Complexes: A Relativistic DFT Study
AU - Wu, Haide
AU - Hemmingsen, Lars Bo Stegeager
AU - Sauer, Stephan P. A.
PY - 2023/12/21
Y1 - 2023/12/21
N2 - Thiolate containing mercury(II) complexes of the general formula [Hg(SR)n]2−n have been of great interest since the toxicity of mercury was recognized. 199Hg nuclear magnetic resonance spectroscopy (NMR) is a powerful tool for characterization of mercury complexes. In this work, the Hg shielding constants in a series of [Hg(SR)n]2−n complexes are therefore investigated computationally with particular emphasis on their geometry dependence. Geometry optimizations and NMR chemical shift calculations are performed at the density functional theory (DFT) level with both the zeroth-order regular approximation (ZORA) and four-component relativistic methods. The four exchange-correlation (XC) functionals PBE0, PBE, B3LYP and BLYP are used in combination with either Dyall’s Gaussian-type (GTO) or Slater-type orbitals (STOs) basis sets. Comparing ZORA and four-component calculations, one observes that the calculated shielding constants for a given molecular geometry have a constant difference of ∼1070 ppm. This confirms that ZORA is an acceptable relativistic method to compute NMR chemical shifts. The combinations of 4-component/PBE0/v3z and ZORA/PBE0/QZ4P are applied to explore the geometry dependence of the isotropic shielding. For a given coordination number the distance between mercury and sulfur is the key factor affecting the shielding constant, while changes in bond and dihedral angles and even different side groups have relatively little impact.
AB - Thiolate containing mercury(II) complexes of the general formula [Hg(SR)n]2−n have been of great interest since the toxicity of mercury was recognized. 199Hg nuclear magnetic resonance spectroscopy (NMR) is a powerful tool for characterization of mercury complexes. In this work, the Hg shielding constants in a series of [Hg(SR)n]2−n complexes are therefore investigated computationally with particular emphasis on their geometry dependence. Geometry optimizations and NMR chemical shift calculations are performed at the density functional theory (DFT) level with both the zeroth-order regular approximation (ZORA) and four-component relativistic methods. The four exchange-correlation (XC) functionals PBE0, PBE, B3LYP and BLYP are used in combination with either Dyall’s Gaussian-type (GTO) or Slater-type orbitals (STOs) basis sets. Comparing ZORA and four-component calculations, one observes that the calculated shielding constants for a given molecular geometry have a constant difference of ∼1070 ppm. This confirms that ZORA is an acceptable relativistic method to compute NMR chemical shifts. The combinations of 4-component/PBE0/v3z and ZORA/PBE0/QZ4P are applied to explore the geometry dependence of the isotropic shielding. For a given coordination number the distance between mercury and sulfur is the key factor affecting the shielding constant, while changes in bond and dihedral angles and even different side groups have relatively little impact.
KW - Faculty of Science
KW - NMR
KW - mercury
KW - ZORA
KW - Relativistic Effects
KW - 4-Component Calculations
KW - Density Functional Theory
U2 - 10.48550/arXiv.2312.13120
DO - 10.48550/arXiv.2312.13120
M3 - Preprint
VL - 2312.13120
BT - On the Geometry Dependence of the NMR Chemical Shift of Mercury in Thiolate Complexes: A Relativistic DFT Study
PB - arxiv.org
ER -
ID: 376995200