TY - JOUR
T1 - Spatial Contributions to H-1 NMR Chemical Shifts of Free-Base Porphyrinoids
AU - Fliegl, Heike
AU - Dimitrova, Maria
AU - Berger, Raphael J. F.
AU - Sundholm, Dage
PY - 2021/9/5
Y1 - 2021/9/5
N2 - A recently developed methodology for calculating, analyzing, and visualizing nuclear magnetic shielding densities is used for studying spatial contributions including ring-current contributions to 1H nuclear magnetic resonance (NMR) chemical shifts of aromatic and anti-aromatic free-base porphyrinoids. Our approach allows a visual inspection of the spatial origin of the positive (shielding) and negative (deshielding) contributions to the nuclear magnetic shielding constants. Diatropic and paratropic current-density fluxes yield both shielding and deshielding contributions implying that not merely the tropicity of the current density determines whether the contribution has a shielding or deshielding character. Instead the shielding or deshielding contribution is determined by the direction of the current-density flux with respect to the studied nucleus.
AB - A recently developed methodology for calculating, analyzing, and visualizing nuclear magnetic shielding densities is used for studying spatial contributions including ring-current contributions to 1H nuclear magnetic resonance (NMR) chemical shifts of aromatic and anti-aromatic free-base porphyrinoids. Our approach allows a visual inspection of the spatial origin of the positive (shielding) and negative (deshielding) contributions to the nuclear magnetic shielding constants. Diatropic and paratropic current-density fluxes yield both shielding and deshielding contributions implying that not merely the tropicity of the current density determines whether the contribution has a shielding or deshielding character. Instead the shielding or deshielding contribution is determined by the direction of the current-density flux with respect to the studied nucleus.
KW - Theretical Chemistry
KW - London orbitals
KW - gauge-including atomic orbitals
KW - magnetically induced current densities
KW - nuclear magnetic shielding constants
UR - https://doi.org/10.3390/chemistry3030072
UR - https://www.mendeley.com/catalogue/90f6497d-6b1e-313b-8de1-7a92697b587f/
U2 - 10.3390/chemistry3030072
DO - 10.3390/chemistry3030072
M3 - Article
SN - 0861-9255
VL - 3
SP - 1005
EP - 1021
JO - Chemistry
JF - Chemistry
ER -