Five-Coordinate Low-Spin {FeNO}7 PNP Pincer Complexes

The synthesis and characterization of air-stable cationic mono nitrosonium Fe­(I) PNP pincer complexes of the type [Fe­(PNP)­(NO)­Cl]+ are described. These complexes are obtained via direct nitroslyation of [Fe­(PNP)­Cl2] with nitric oxide at ambient pressure. On the basis of magnetic and EPR measurements as well as DFT calculations, these compounds were found to adopt a low-spin d7 configuration and feature a nearly linear bound NO ligand suggesting FeINO+ rather than FeIINO• character. X-ray structures of all nitrosonium Fe­(I) PNP complexes are presented. Preliminary investigations reveal that [Fe­(PNPNH-iPr)­(NO)­(Cl)]+ efficiently catalyzes the conversion of primary alcohols and aromatic and benzylic amines to yield mono N-alkylated amines in good isolated yields.