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.
Carbon-13 isotropic shielding constants and C–F spin–spin coupling constants for fluorobenzene, 3- and 4-dimethylaminofluorobenzene as well as for their tricarbonylchromium complexes have been calculated using DFT methods.
The calculation of NMR parameters for natural products was pioneered by Bifulco and coworkers in 2002. Since then, modelling 1H and 13C chemical shifts and spin-spin coupling constants for this...
The 1H nmr spectral parameters are extracted for a 4 mol% solution of 2-methylthiobenzaldehyde in CCl4 at 305 K. The long-range spin–spin coupling constants involving the aldehydic and methyl protons are consistent only with a preferred conformation in which all heavy atoms are coplanar, as are the chemical shifts of the ring and methyl protons. This conclusion contradicts previous interpretations of the dipole moment, the nmr parameters, and of the infrared data for CCl4 solutions. The present data show that the O-syn and O-anti forms of the compound are present in roughly equal proportions.
A successful DFT calculation of carbon-13 NMR chemical shifts and carbon–fluorine spin–spin coupling constants in (η6-fluoroarene)tricarbonylchromium complexes