INVESTIGADORES
AUCAR Ignacio Agustin
congresos y reuniones científicas
Título:
Absolute NMR shielding scales in methyl halides obtained from nuclear spin-rotation constants
Autor/es:
BAJAC, DANIEL F. E.; AUCAR, I. AGUSTÍN; AUCAR, GUSTAVO ADOLFO
Reunión:
Otro; LatinXChem; 2021
Resumen:
The non-relativistic "Ramsey-Flygare relationship'" is the most used procedure to obtain semi-experimental NMR absolute shieldings by a correspondence between NMR shieldings (σ) and nuclear spin-rotation (NSR) constants M. One of its generalizations to the relativistic framework is known as the M-V model, which was proposed few year ago by some of the authors of this poster. This model includes terms that does not have non-relativistic counterparts and also include the paramagnetic contribution to the NMR shielding of nuclei in free atoms. All this ensures that its results fit quite well with those of four-component (4c) calculations. The first application of the M-V model to non-linear molecules, like CH3X (X = F, Cl, Br and I) was published recently, and is presented in this poster. The analysis of each electronic mechanism of σ according to the M-V model shows that most of their electron correlation effects are strongly related with the same effects in M. By including experimental data of M in the M-V model most of the correlation effects are accurately taken into account for the absolute values of σ.