Phosphaniminato‐Komplexe des Zirconiums: Die Kristallstrukturen von [ZrCl3(NPPh3)(HNPPh3)2] und [ZrCl2(NPPh3)2(HNPPh3)2]

Phosphoraneiminato Complexes of Zirconium: Crystal Structures of [ZrCl₃(NPPh₃)(HNPPh₃)₂] and [ZrCl₂(NPPh₃)₂(HNPPh₃)₂] The phosphoraneiminato complexes [ZrCl₃(NPPh₃)(HNPPh₃)₂] ( 1 ) and [ZrCl₂(NPPh₃)₂(HNPPh₃)₂] ( 2 ) have been obtained by reaction of [ZrCl₄(THF)₂] with [CsNPPh₃]₄ in THF solution to give colourless moisture sensitive crystals which are characterized by X‐ray structure determinations. [ZrCl₃(NPPh₃)(HNPPh₃)₂] ( 1 ): Space group P 1, Z = 2, lattice dimensions at 193 K: a = 1209.4(2); b = 1480.8(2); c = 1814.2(2) pm; α = 71.203(13)°, β = 71.216(13)°, γ = 74.401(13)°; R = 0.0476. The zirconium atom of 1 is oktahedrally coordinated by the three chlorine atoms in meridional arrangement and by the three nitrogen atoms of the (NPPh₃^–) ligand and of the two phosphane imine molecules HNPPh₃. The ZrN bond distance of the (NPPh₃^–) group (193.5 pm) corresponds with a double bond. [ZrCl₂(NPPh₃)₂(HNPPh₃)₂] ( 2 ): Space group P 1, Z = 4, lattice dimensions at 193 K: a = 1447.6(2); b = 1925.7(2), c = 2457.0(2) pm; α = 67.317(12)°, β = 87.376(12)°, γ = 87.103(13)°; R = 0.0408. The zirconium atom in 2 is octahedrally coordinated by the two chlorine atoms in trans position, and by the nitrogen atoms of the two (NPPh₃^–) groups as well as by the two HNPPh₃ molecules. The ZrN distance of the (NPPh₃^–) ligands (198.9 and 202.0 pm) suggest some π‐interaction between the zirconium and the nitrogen atoms.