From NO to NTe: <i>In Silico</i> Study of Ruthenium Compounds Containing Chalcogenonitrosyl Ligands

Ruthenium compounds bearing chalcogenonitrosyl ligands (NE, where E = O, S, Se, Te) represent a unique class of molecules with intriguing bonding patterns and potential relevance in redox-active systems. This manuscript presents a systematic investigation of a series of ruthenium-chalcogenonitrosyl compounds through combined Density Functional Theory (DFT) and generalized Kohn-Sham energy decomposition analysis (GKS-EDA) calculations. The compounds were evaluated both before and after one-electron reduction, focusing on their structural and electronic properties. Our results reveal clear trends in geometry, bond strength, and charge distribution, providing insight into the fundamental bonding interactions that govern the stability and redox behavior of these species. In particular, we examine the nature of the Ru-NE bond across the chalcogen series and evaluate the effects of one-electron reduction on these systems. The results demonstrate that one-electron reduction favors the labilization of the chalcogenonitrosyl ligands, as demonstrated by spin density plots and wave function analyses. The total interaction energy (Δ<i>E</i> ^tot) for the Ru-NE bond indicates that, following one-electron reduction, this interaction is weakened by a factor of 2.9 to 4.2 (from NTe to NO) compared to the neutral species, accompanied by a decrease in the Ru-N-E angle of approximately 30°.