The bonding situations in ruthenium chalcogenonitrosyl compounds: a physical reasoning

This research presents, for the first time, a comprehensive and rigorous investigation of ruthenium(II) chalcogenonitrosyl bonding situations in two sets of coordination compounds: [Ru(NE)Cl₂(L_OEt)] (1a-4a) and [Ru(NE)Cl₂(L_OEt)]^- (1b-4b), where E = O, S, Se, Te. Prior to and following the one-electron reduction, the Ru-NE bonding situations were subjected to analysis. The calculated geometric parameters indicate that both the Ru-NE and N-E bond lengths are susceptible to variation depending on the nature of the chalcogen employed. Furthermore, the results demonstrate that the one-electron reduction process serves to diminish the NE double bond character. The generalized Kohn-Sham energy decomposition analysis (GKS-EDA) was conducted to illustrate the Ru-NE bonding scenarios prior to and following the one-electron reduction. The results provide valuable insights into the nature of Ru(II)-NE (E = O, S, Se, Te) bonds, the influence of chalcogens on ruthenium compounds, as well as how the one-electron reduction affects the release of NE groups. The main findings indicate that the total interaction energy, prior to the one-electron reduction, is three to four times more stabilizing than in the reduced analogs, confirming that the reduction unequivocally enhances the lability of the Ru-NE bond even when heavier chalcogen analogues are employed.