Nature of the Ru−NO Coordination Bond: Kohn–Sham Molecular Orbital and Energy Decomposition Analysis

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.