The reaction of 2-bromo-1, 3-bis(bromomethyl)benzene with 3, 5-dimethylpyrazole and 1H-indazole yields the tridentate ligands 2-bromo-1, 3-bis(3, 5-dimethylpirazol-1-ylmethyl)benzene (1) and 2-bromo-1, 3-bis(indazol-2-ylmethyl)benzene (2). These compounds react with [Ni(cod)2] in tetrahydrofuran (thf) to form the oxidative addition complexes [NiBr{1, 3-bis(azolylmethyl)phenyl-N, C, N}], azol = 3, 5-dimethylpyrazol (3), indazol (4), which were isolated in good yields as stable yellow solids and characterized by elemental analysis, Fourier-transform infrared spectroscopy (FTIR), mass spectroscopy and nuclear magnetic resonance (NMR). In addition, the molecular structures of 2 and 4 were determined by single-crystal X-ray diffraction analysis. Complex 4 was tested as a catalyst in ethylene polymerization reaction
nickel; tridentate ligands; cyclometalated complexes; catalytic activity
