High-Frequency C-13 and Si-29 NMR Chemical Shifts in Diamagnetic Low-Valence Compounds of TI-I and Pb-II: Decisive Role of Relativistic Effects

Investor logo
Investor logo

Warning

This publication doesn't include Faculty of Education. It includes Central European Institute of Technology. Official publication website can be found on muni.cz.
Authors

VÍCHA Jan MAREK Radek STRAKA Michal

Year of publication 2016
Type Article in Periodical
Magazine / Source Inorganic Chemistry
MU Faculty or unit

Central European Institute of Technology

Citation
Web DOI: 10.1021/acs.inorgchem.5b02689
Doi http://dx.doi.org/10.1021/acs.inorgchem.5b02689
Field Inorganic chemistry
Keywords Density-Functional Theory; Relativistic effects; Spin-orbit coupling; Magnetic coupling;
Attached files
Description The C-13 and Si-29 NMR signals of ligand atoms directly bonded to TII or Pb-II heavy-element centers are predicted to resonate at very high frequencies, up to 400 ppm for C-13 and over 1000 ppm for Si-29, outside the typical experimental NMR chemical-shift ranges for a given type of nuclei. The large C-13 and Si-29 NMR chemical shifts are ascribed to sizable relativistic spin-orbit effects, which can amount to more than 200 ppm for C-13 and more than 1000 ppm for Si-29, values unexpected for diamagnetic compounds of the main group elements. The origin of the vast spin-orbit contributions to the C-13 and Si-29 NMR shifts is traced to the highly efficient 6p -> 6p* metal-based orbital magnetic couplings and related to the 6p orbital-based bonding together with the low-energy gaps between the occupied and virtual orbital subspaces in the subvalent TII and Pb-II compounds. New NMR spectral regions for these compounds are suggested based on the fully relativistic density functional theory calculations in the Dirac-Coulomb framework carefully calibrated on the experimentally known NMR data for TII and Pb-II complexes.
Related projects:

You are running an old browser version. We recommend updating your browser to its latest version.