Nitric oxide and nitroxyl formation in the reduction of trans-tetraamminenitrosyltriethylphosphiteruthenium(II) ion

The reduction of trans-[Ru(NO)(NH3)4(P(OEt)3)]3+ ion was investigated in aqueous medium. Due to the phosphite ligand trans-effect and trans-influence, this complex selectively releases NO or HNO after one or two electrons reduction centered at the nitrosonium ligand (NO+). These reactions were carried out through electrochemical reduction and using Eu2+ and zinc amalgam, and the products were identified using electrochemical and spectroscopic techniques. Only the reduction of the nitrosonium ligand to nitric oxide is observed when europium is used as reductant. When the reaction is carried out with Zn(Hg), nitric oxide formation was not observed and N2O, an indirect marker of HNO, is detected in solution.