Zirconium Complexes Supported by an N-Perfluoro-Arylated Diamidopyridyl Ligand: Synthesis of Hydrazinediido Complexes

The N-perfluoro-phenylated pyridyldiamine H2N2PFPNpy (1) has been prepared by a palladium-catalyzed coupling of hexafluorobenzene and the diamine (H2NCH2)2C­(CH3)­(2-C5H4N) using the palladacycle trans-di­(μ-acetato)­bis­[o-(di-o-tolylphosphino)­benzyl]­palladium­(II) as catalyst. Reactions of H2N2PFPNpy and Zr­(NMe2)4 at room temperature or 90 °C led to the complexes [(NPFPN2TFAPNpy)­ZrF­(NMe2)] (2) and [(N2TFAPNpy)­ZrF2] (3) in which one or two dimethylamido groups replaced one or two ortho fluorine atoms of the pentafluorophenyl groups in the ligand. Reaction of Me3SiX (X = Cl, I) with [(N2TFAPNpy)­ZrF2] (3) resulted in the formation of mixed halogenated complexes [(N2TFAPNpy)­ZrFI] (4) and [(N2TFAPNpy)­ZrFCl] (5) in which the axially bound fluorido ligand is substituted. Reaction of [(N2TFAPNpy)­ZrF2] (3) with LiNHNPh2 afforded the monohydrazido(1−) complex [(N2TFAPNpy)­ZrF­(NHNPh2)] (6) which was converted to the dimeric fluoro-potassium bridged hydrazinediido complex [Zr­(N2TFAPNpy)­FNNPh2K]2 (7) using KHMDS. The corresponding reaction with LiHMDS yielded the monomeric, donor free complex [Zr­(N2TFAPNpy)­NNPh2] (8).