RESUMO
Ruthenium nitrosyl complexes have received considerable attention due to the fact that they are able to store, transfer and release NO in a controlled manner. It is well-known that the NO reactivity of ruthenium nitrosyl complexes can be modulated with the judicious choice of equatorial and axial ligands. In this piece of research we elucidate the nature of the Ru-NO and Ru-NO2 bonding in a cis-[Ru(NO)(NO2)(bpy)2](2+) complex energy decomposition (Su-Li EDA) and topological (e.g., QTAIM) and natural bond orbital analysis. It was observed that the strength of these bonds is directly correlated with the relative stability of isomers involved in nitro-nitrito and nitrosyl-isonitrosyl isomerism, as described previously by Coppens and Ooyama.
Assuntos
2,2'-Dipiridil/química , Óxido Nítrico/química , Dióxido de Nitrogênio/química , Compostos Organometálicos/química , Teoria Quântica , Rutênio/química , EstereoisomerismoRESUMO
Ruthenium complexes including nitrosyl or nitrite complexes are particularly interesting because they can not only scavenge but also release nitric oxide in a controlled manner, regulating the NO-level in vivo. The judicious choice of ligands attached to the [RuNO] core has been shown to be a suitable strategy to modulate NO reactivity in these complexes. In order to understand the influence of different equatorial ligands on the electronic structure of the Ru-NO chemical bonding, and thus on the reactivity of the coordinated NO, we propose an investigation of the nature of the Ru-NO chemical bond by means of energy decomposition analysis (EDA), considering tetraamine and tetraazamacrocycles as equatorial ligands, prior to and after the reduction of the {RuNO}(6) moiety by one electron. This investigation provides a deep insight into the Ru-NO bonding situation, which is fundamental in designing new ruthenium nitrosyl complexes with potential biological applications.