Nickel(II) complex based on bis-(1-(pyridin-2-yl-methyl)-benzimidazol-2-yl-methyl) ether and its utilization in the oxidation of 2-amino-4-<i>tert</i>-butylphenol

Abstract

A mononuclear nickel(II) complex [Ni(L)₂].(NO₃)₂.H₂O is synthesized utilizing a bis-benzimidazolyl ligand (L = bis-(1-(pyridin-2-yl-methyl)-benzimidazol-2-yl-methyl)ether) and characterized by single-crystal X-ray diffraction, elemental analysis, UV-vis and IR spectroscopy. Ni(II) complex crystallizes in the tetragonal system with space group I4₁/a and appears to be propeller-shaped when viewed along the <i>c</i>-axis. The [Ni(L)₂].(NO₃)₂ complex has been utilized for the oxidation for 2-amino-4-<i>tert</i>-butylphenol to 4-<i>tert</i>-butyl-<i>o</i>-benzoquinone in the presence of hydrogen peroxide and the average rate of reaction is calculated to be 63×10^–7 <i>M</i> min^–1. The presence of externally added acetate ion tends to inhibit the rate of reaction.