First-Row Transition Metal−Halide Complexes Supported by a Monoanionic [N₂P₂] Ligand

Metal−halide complexes of a multidentate monoanionic ligand tBuN(H)SiMe2N(CH2CH2PiPr2)2, H[N2P2], with Ti, V, Cr, Mn, Fe, Co, and Ni have been isolated and characterized. X-ray crystallographic studies were performed on [N2P2]TiCl2 (3), [N2P2]CrCl2 (5), [N2P2]MnCl (6), [N2P2]FeCl (7), [N2P2]CoCl (8), and [N2P2]NiBr (9), and the results revealed that the [N2P2] ligand exhibits considerable flexibility in the manner in which it binds to first-row metals and that three distinct coordination modes are observed: κ3-N2P (Ti), κ3-NP2 (Mn, Fe, Co), and κ4-N2P2 (Cr, Ni). Electrochemical (CV) data and room-temperature magnetic susceptibilities are also described.