Reactions of molybdenum oxo-complexes with substituted hydrazines. Part 4. The preparation and structure of an anionic molybdenum oxo(diazene) complex

Abstract

The complexes [MoCl(O)(P–P)₂][MoCl₃O(RCON₂Ph)](R = Ph, p-ClC₆H₄,p-MeOC₆H₄, or Me; P–P = Ph₂PCH₂CH₂PPh₂ or Ph₂PCHCHPPh₂) have been prepared by reactions of the hydrazines RCONHNHPh with [{MoCl₂O(P–P)}₂] or [MoCl₃O(P-P)] in refluxing methanol. The crystal and molecular structure of [MoCl(O)(Ph₂PCH₂CH₂PPh₂)₂][MoCl₃O(p-ClC₆H₄CON₂Ph)] has been determined by single-crystal X-ray diffraction methods. The complex crystallises in the triclinic system, space group P with a= 14.87(1), b= 11.84(1), c= 18.37(1)Å, α= 96.1(1), β= 98.8(1), γ= 97.2(1)°, and Z= 2. The geometry of the oxo(diazene) anion is distorted octahedral with the chloride atoms in a mer configuration and the oxygen atom of the diazene ligand is trans to the oxo-function. The Mo–Cl distances are 2.410(6), 2.412(6), and 2.334(7)Å. The MoO terminal distance is 1.620(14)Å and the bond lengths within the diazene ligand indicate considerable delocalisation.