X-ray structures and spectral characterization of simple ruthenium(II) nitrosyl complexes involving the [RuCl4(NO)(DMSO)]− or [RuCl4(NO)(H2O)]− complex anions

Three simple ruthenium nitrosyl complexes of the compositions [Et4N][RuCl4(NO)(DMSO)] (1), [Bu4N][RuCl4(NO)(DMSO)] (2), and [Ph4P][RuCl4(NO)(H2O)]·DMSO (3); where DMSO = dimethyl sulfoxide, Et = ethyl, Bu = butyl and Ph = phenyl, have been synthesized in the single crystal form and their molecular and crystal structures have been determined. The Ru(II) centre is six-coordinated by four chlorido ligands in the equatorial plane and by the N (from NO+) and O (from DMSO in 1 and 2, H2O in 3) atoms in the axial positions forming an RuCl4NO donor set. The complexes have been also characterized by infrared and electronic spectroscopies, conductivity measurements, and thermogravimetric (TG) and differential thermal (DTA) analyses. The spectroscopic investigation is consistent with the {Ru(NO)}6 formulation with NO+ coordinated to the diamagnetic Ru(II) centre. The geometries of the complex anions as well as spectroscopic properties were calculated at the B3LYP/LANL2DZ/cc-pVTZ level of theory. These results were compared with those experimentally determined.