Synthesis and Characterization of Iron, Cobalt, and Nickel [PNP] Pincer Amido Complexes by N–H Activation

The N–H bond activation product [PNP]‐Fe I (PMe 3 ) 2 ( 2 ) was obtained at room temperature by the reaction of diphosphinito [PNP] pincer ligand ((Ph 2 P(C 6 H 4 )) 2 NH ( 1 )) with Fe(PMe 3 ) 4 . Treatment of 1 with Co(PMe 3 ) 4 , CoCl(PMe 3 ) 3 and CoMe(PMe 3 ) 4 afforded the same N–H bond activation product [PNP]‐Co I (PMe 3 ) 2 ( 3 ). In order to have a better understanding of the mechanism of formation of 3 , in situ IR and 1 H NMR spectroscopic investigations were conducted.The reaction of 1 with Ni(PMe 3 ) 4 afforded the ligand replacement complex 4 while a [PNP]‐Ni II Me complex 5 was obtained via deprotonation through the reaction of 1 with NiMe 2 (PMe 3 ) 3 . The molecular structures of 2 – 4 were confirmed by X‐ray diffraction analysis.