High-Frequency1H NMR Chemical Shifts of SnIIand PbIIHydrides Induced by Relativistic Effects: Quest for PbIIHydrides.
The role of relativistic effects on1H NMR chemical shifts of SnIIand PbIIhydrides is investigated by using fully relativistic DFT calculations. The stability of possible PbIIhydride isomers is studied together with their1H NMR chemical shifts, which are predicted in the high-frequency region, up to 90 ppm. These1H signals are dictated by sizable relativistic contributions due to spin-orbit coupling at the heavy atom and can be as large as 80 ppm for a hydrogen atom bound to PbII. Such high-frequency1H NMR chemical shifts of PbIIhydride resonances cannot be detected in the1H NMR spectra with standard experimental setup. Extended1H NMR spectral ranges are thus suggested for studies of PbIIcompounds. Modulation of spin-orbit relativistic contribution to1H NMR chemical shift is found to be important also in the experimentally known SnIIhydrides. Because the1H NMR chemical shifts were found to be rather sensitive to the changes in the coordination sphere of the central metal in both SnIIand PbIIhydrides, their application for structural investigation is suggested.
Center of Polymer Systems, University Institute, Tomas Bata University in Zlín , Třída T. Bati 5678, CZ-76001 Zlín, Czech Republic.
Jan
J
Vícha
CEITEC-Central European Institute of Technology, Masaryk University , Kamenice 5/A4, CZ-62500 Brno, Czech Republic.
Radek
R
Marek
Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences , Flemingovo nám. 2, CZ-16610 Prague, Czech Republic.
Michal
M
Straka