In the present work we describe the formation of primary aromatic and aliphatic coordinated nitrosamines by reaction of the extremely reactive K[IrCl 5 -NO] with p-toluidine and 2,2,2-trifluoroethylamine, respectively. After the counteranion of the product was changed to tetraphenylphosphonium, crystal structures could be determined by X-ray diffraction. Complexes containing the highly unstable primary nitrosamines as ligands are generally scarce; moreover, to our knowledge this is the first example of isolated primary nitrosamines coordinated to a metal center through the NO moiety.

The reaction of [Ru(bpy) 2 (NO)Cl] 2+ and [Fe(CN) 5 NO] 2with n-butylamine has been studied as a plausible route for obtaining aliphatic diazonium ions stabilized by coordination. These reactions yield a variety of products originating mainly by direct attack of nucleophiles on the intermediate carbocation (or diazonium ion) and by rearrangement of the carbocation or the diazonium ion. The ratio of unrearranged to rearranged products can be taken as an experimental measurement of the stabilization of the diazonium ions. DFT-computed results suggest that the stabilization by complexation of the diazonium ions is larger in the ironpentacyano complex, in agreement with the fact that no rearrangement products are observed in the reaction of this species with n-butylamine.