Stable Salts of Heteroleptic Iron Carbonyl/Nitrosyl Cations

The oxidation of Fe(CO)(5) with the [NO](+) salt of the weakly coordinating perfluoroalkoxyaluminate anion [F‐{Al(OR(F))(3)}(2)](−) (R(F)=C(CF(3))(3)) leads to stable salts of the 18 valence electron (VE) species [Fe(CO)(4)(NO)](+) and [Fe(CO)(NO)(3)](+) with the Enemark–Feltham numbers of {FeNO}(8) and {FeNO}(10). This finally concludes the triad of heteroleptic iron carbonyl/nitrosyl complexes, since the first discovery of the anionic ([Fe(CO)(3)(NO)](−)) and neutral ([Fe(CO)(2)(NO)(2)]) species over 80 years ago. Both complexes were fully characterized (IR, Raman, NMR, UV/Vis, scXRD, pXRD) and are stable at room temperature under inert conditions over months and may serve as useful starting materials for further investigations.