Synthesis, characterization, and catalytic studies of new benzimidazole-, benzthiazole-, and benzazole-linked iron(III) porphyrins

Three new tailed iron(III) porphyrin complexes, 5-[3-(2-benzimidazolethiol)butoxyphenyl]-10,15,20-tri(4-methylphenyl) porphyrinatoiron(III) chloride [m-Bz-Im(BO)Ph(4-MePh)(3)PFe(III)Cl] (P = porphyrin), 5-[3-(2-benzthiazolethiol)butoxyphenyl] 10,15,20-tri(4-methylphenyl)porphyrinatoiron(III) chloride [m-BzTa(Bo)Ph(4-MePh)(3)PFe(III)Cl], and 5-[3-(2-benzazolethiol)butoxyphenyl]-10,15,20-tri(4-methylphenyl)porphyrinatoiron (III) chloride [m-BzAz(BO)Ph(4-MePh)(3)PFe(III)Cl], have been prepared and characterized by elemental analyses,H-1-NMR, IR, UV-vis, mass, ESR, and magnetic circular dichroism spectra. The catalytic activities of these complexes in the hydroxylation of cyclohexane with O-2 as the oxygen source were investigated under mild conditions. The results indicated that these complexes had higher catalytic activity than tetra(4-methylphenyl)pophyrinatoiron(LII) chloride [(4-MePh)(4)PFe(LII)Cl] due to the coordination and stabilization of the terminal groups benzimidazole (BzIm(-)), benzthiazole (BzTa(-)), and benzazole (BzAz(-)) to the iron centers.