DFT Calculations of 99Ru Chemical Shifts with All-Electron and Effective Core Potential Basis Sets

The nuclear shielding of 99Ru in several complexes has been investigated computationally by DFT methods with effective core potential and all- electron basis sets. Shieldings calculated with ECP bases correlate very satisfactorily with available experimental data, even though they are ca. one order of magnitude lower than the experimental values. The influence of molecular geometry (semiempirical vs. DFT) on the nuclear shielding is also examined and discussed, particularly in the case of species containing Ru S bonds (RuCl2(DMSO)4 and PW11O39Ru(DMSO)5). It is shown that such calculations can greatly help signal assignment in 99Ru NMR spectra of mono- and polynuclear complexes.