INDO [intermediate neglect of differential overlap] perturbation theory of magnetic shielding constants. Cabon-13 chemical shifts

1972 ◽  
Vol 94 (12) ◽  
pp. 4069-4076 ◽  
Author(s):  
Paul D. Ellis ◽  
Gary E. Maciel ◽  
James W. McIver
Keyword(s):  
Perturbation Theory ◽  
Chemical Shifts ◽  
Magnetic Shielding ◽  
Shielding Constants ◽  
Neglect Of Differential Overlap

MNDO/GIAO perturbation theory of magnetic shielding constants

1987 ◽  
Vol 5 (2) ◽  
pp. 195-197
Author(s):  
Wu Wei-Xiong ◽  
You Xiao-Zeng ◽  
Dai An-Bang
Keyword(s):  
Perturbation Theory ◽  
Magnetic Shielding ◽  
Shielding Constants

Chemical Shifts and Coupling Constants in Copper (I)-Compounds by 63Cu and 65Cu FT-NMR Studies

1978 ◽  
Vol 33 (9) ◽  
pp. 1021-1024
Author(s):  
O. Lutz ◽  
H. Oehler ◽  
P. Kroneck
Keyword(s):  
Isotope Effect ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Magnetic Shielding ◽  
Nmr Studies ◽  
Nmr Chemical Shifts ◽  
Shielding Constants ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling

Using 63Cu and 65Cu FT NMR, chemical shifts and large indirect spin-spin-coupling constants with phosphorus were measured in dissolved copper (I) compounds. The nuclear magnetic shielding constants derived from the chemical shifts were given in the atomic reference scale. No isotope effect for spin-spin-coupling constants was found.

scholarly journals Spatial Contributions to 1H NMR Chemical Shifts of Free-Base Porphyrinoids

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 1005-1021
Author(s):  
Heike Fliegl ◽  
Maria Dimitrova ◽  
Raphael J. F. Berger ◽  
Dage Sundholm
Keyword(s):  
Current Density ◽  
Visual Inspection ◽  
Ring Current ◽  
Chemical Shifts ◽  
Magnetic Shielding ◽  
Free Base ◽  
Nmr Chemical Shifts ◽  
1H Nuclear Magnetic Resonance ◽  
Shielding Constants ◽  
Nuclear Magnetic

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.

Quasirelativistic study of125Te nuclear magnetic shielding constants and chemical shifts

2001 ◽  
Vol 22 (13) ◽  
pp. 1502-1508 ◽  
Author(s):  
Masahiko Hada ◽  
Jian Wan ◽  
Ryoichi Fukuda ◽  
Hiroshi Nakatsuji
Keyword(s):  
Chemical Shifts ◽  
Magnetic Shielding ◽  
Shielding Constants ◽  
Nuclear Magnetic

Carbon-13/carbon-12 isotope effects on nitrogen-15 chemical shielding in some diamagnetic cyano complexes

1982 ◽  
Vol 60 (17) ◽  
pp. 2194-2197 ◽  
Author(s):  
Roderick E. Wasylishen
Keyword(s):  
Transition Metal ◽  
High Field ◽  
Chemical Shifts ◽  
Isotope Effects ◽  
Chemical Shielding ◽  
Cyanide Ion ◽  
Theoretical Formulation ◽  
Metal Cyanides ◽  
Shielding Constants ◽  
Cyano Complexes

Carbon-13/carbon-12 isotope-induced 15N chemical shifts of 0.06 to 0.10 ppm have been observed for the cyanide ion and several transition metal cyanides. In each case, the 15N resonance of the 13C labelled isotopomers is to high field of that in the corresponding carbon-12 species. The sensitivity of the 15N and 13C shielding constants in the cyanide ion to small changes in the CN bond length are evaluated using the theoretical formulation of Jameson: (∂σ(15N)/∂r)e = −872 ± 160 ppm/Å and (∂σ(13C)/∂r)e = −473 ± 90 ppm/Å. Nitrogen-15 chemical shifts in the metal complexes exhibit basically the same behaviour as do the 13C chemical shifts in these same complexes.

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