Nuclear charge distribution effects in shielding and spin-rotation constants within a relativistic framework

AUCAR, IGNACIO AGUSTÍN; GIMENEZ, CARLOS ARIEL; AUCAR, GUSTAVO ADOLFO

Marburg

Conferencia; 12th International Conference on Relativistic Effects in Heavy-Element Chemistry and Physics; 2017

In the last decades, the influence of the nuclear charge-distribution effects (NChDE) onNMR magnetic properties has been highlighted[1]. In this work, we analyze the NChDEon nuclear magnetic shieldings ( σ ) employing a new procedure to obtain its absolute valuesstarting from measurable nuclear spin-rotation (SR) constants (M)[2].The NChDE on σ and M are analyzed employing point-like and Gaussian-like nuclearmodels (PNM and GNM, respectively) to describe the electron-nucleus coulombic interac-tion. According to our results, both properties are sensitive to the NChDE. We show thatthese effects are of relativistic nature. The NChDE are analyzed in three linear molecules:HBr, HI and HAt. Employing the new relation between σ and M, we arrive to an importantfinding: the NChDE are mainly due to core mechanisms, which are present in the shieldingof both, nuclei in a molecule and in a free atom. Furthermore, the NChDE are very importantfor the SR constants of nuclei in very-heavy-atom-containing compounds (6 th row of the Pe-riodic Table). This is the case of At in HAt, where we obtain (as four-component results)M At = 0.31 kHz when a PNM is employed, and M At = -41.01 kHz when a GNM is used.