Reactions of Cp₂MCl₂ (M=Ti or Zr) with Imine-Oxime Ligands. Formation of Metallacycles

Abstract: The reactions of bis(cyclopentadienyl)titanium(IV)/zirconium(IV) dichloridewith a series of imine-oxime ligands (LH₂), derived by condensing benzil-α-monoxime and2-phenylenediamine, 4-phenylenediamine, 4-methyl-2-phenylenediamine, 2,6-diamino-pyridine, have been studied in anhydrous tetrahydrofuran in the presence of base andmetallocycles of the [Cp₂M(L)] (M=Ti or Zr) type have been isolated. Tentative structureshave been proposed for the products based on elemental analysis, electrical conductance andspectral (electronic, IR and ¹H-NMR) data. Proton NMR spectra indicate that on the NMRtime scale there is rapid rotation of the cyclopentadienyl ring around the metal-ring axis at25^oC. Studies were conducted to assess the growth inhibiting potential of the complexessynthesized and the ligands against various bacterial strains.