Abstract
We have analyzed structure, stability, and Ru-NO bonding of the trans-[RuCl(NO)(NH(3))(4)](2+) complex by using relativistic density functional theory. First, we focus on the bond dissociation energies associated with the three canonical dissociation modes leading to [RuCl(NH(3))(4)](+)+NO(+), [RuCl(NH(3))(4)](2+)+NO, and [RuCl(NH(3))(4)](3+)+NO(-). The main objective is to understand the Ru-NO(+) bonding mechanism in the conceptual framework of Kohn-Sham molecular orbital theory in combination with a quantitative energy decomposition analysis. In our analyses, we have addressed the importance of the synergism between Ru-NO(+) σ-donation and π-backdonation as well as the so-called negative trans influence of the Cl(-) ligand on the Ru-NO bond. For completeness, the Ru-NO(+) bonding mechanism is compared with that of the corresponding Ru-CO bond.