Density functional computations of ⁹⁹Ru chemical shifts: Relativistic effects, influence of the density functional, and study of solvent effects on fac - [Ru(CO)₃I₃]^-

Solvent effects on the ⁹⁹Ru NMR chemical shift of the complex fac - [Ru(CO)₃I₃] are investigated computationally using density functional theory. Further, benchmark calculations of the ⁹⁹Ru shift for a set of ten Ru complexes have been performed in order to calibrate the computational model and to determine the importance of relativistic effects on the ⁹⁹Ru nuclear magnetic shielding and on the chemical shift. A computational model for fac - [Ru(CO)₃I ₃]^- that includes both explicit solvent molecules and a continuum model is shown to yield the best agreement with experiment. Relativistic corrections are shown to be of minor importance for determining ⁹⁹Ru chemical shifts. On the other hand, the nature of the density functional is of importance. In agreement with literature data for ligand trends of ⁹⁹Ru chemical shifts, the chemical shift range for different solvents is also best reproduced by a hybrid functional.