Iron and vanadium complexes bearing bidentate ketiminate ligand: Synthesis, structural characterization and catalytic activity for MMA polymerization

Two novel iron and vanadium compounds, [OCMeCHCMeNAr]2Fe (1) and [OCMeCHCMeNAr]2VCl (2) have been synthesized by the reaction of FeCl2 with Li[OCMeCHCMeNAr] in THF and VCl3(THF)3 with OCMeCHCMeNHAr, in toluene and triethylamine, respectively, where Ar = 2,6-diisopropylphenyl. Both the complexes have been systematically characterized by elemental analysis, NMR spectroscopy and exhibit paramagnetically shifted resonances, with relative intensities as expected for the η2-ketiminate ligands. Single crystal X-ray structural analysis reveals that compound 1 adopts a distorted tetrahedral geometry consisting with a C2 symmetry where as in 2, the geometry around the vanadium atom can be described as a trigonal bipyramid. Concerning the atom-transfer radical polymerization behavior, complex 1 and 2 shows their catalytic activity on polymerization of methyl methacrylate (MMA) in toluene.