Influence of Crystal Packing on an Organometallic Ruthenium(IV) Complex Structure: The Right Distance for the Right Reason

The chemically relevant intramolecular bond distance between a eta(3)-allylic system and the metal center in a ruthenium complex has been reinvestigated by state-of-the-art dispersion-corrected DFT calculations. Previous works revealed significant deviations between the experimental X-ray crystal structure and results of molecular DFT gas-phase calculations. It was stated that this complex represents a general failure of DFT for transition-metal complex geometries. Our work shows that periodic DFT-D3 calculations for the crystal excellently reproduce all experimental data. The previously found deviations are attributed to crystal packing, the counterions, and improperly accounted dispersion interactions in the theoretical treatment.