Preparation, characterization and catalytic oxidation properties of tris[2-(2-pyridyl)benzimidazole]iron(II) complexes

Complexes [Fe(Hpbi)(3)](ClO4)(2) (1) and [Fe(Hpbi)(3)](SbF6)(2) (2) (Hpbi = 2-(2-pyridyl)benzimidazole) were prepared by a modified method and characterized by IR, H-1 and C-13 NMR, mass spectrometry, electron paramagnetic resonance spectra and elemental analysis. The catalytic activities of 1 and 2 were evaluated for the oxidation of cyclohexene, cyclohexane, ethylbenzene and adamantane with tert-butylhydroperoxide or H2O2 as oxidant, and the results were compared with the properties of their analogue [Fe(bpy)(3)](SbF6)(2) (3). Complexes 1 and 2 both afforded the ketonization product for the oxidation of ethylbenzene and the hydroxylation product for adamantane. Copyright (C) 2004 John Wiley Sons, Ltd.