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-tert-butylphenol

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 c-axis. The [Ni(L)2].(NO3)2 complex has been utilized for the oxidation for 2-amino-4-tert-butylphenol to 4-tert-butyl-o-benzoquinone in the presence of hydrogen peroxide and the average rate of reaction is calculated to be 63×10–7 M min–1. The presence of externally added acetate ion tends to inhibit the rate of reaction

Synthesis, spectral and structural characterization of Cu(II) complexes of a tridentate NNO donor Schiff base carrying a pendant benzimidazolyl arm

775-780Three new Cu(II) complexes of a Schiff base ligand, 2-[2-(1H-benzo[d]imidazol-2-yl)ethylimino)methyl]phenol, (HL), derived from 2-aminoethylbenzimidazolyl and salicylaldehyde have been synthesized and characterized by elemental analysis and electronic and IR spectroscopy. Results show that HL acts as tridentate ligand and coordinates through the imine nitrogen of benzimidazole ring, the azomethine nitrogen and a deprotonated phenolic oxygen of the Schiff base. One of the complex with the composition [Cu(L)CH3COO] has been structurally characterized. X-ray diffraction data reveals that the compound crystallizes in monoclinic space group P21/c with cell parameters of a = 12.8602(8) Å, b = 18.1466(10) Å, c = 8.1250(4) Å, α = 90º, β = 103.757(6) º, γ = 90º and Z = 4. The copper(II) ion adopts a distorted square planar geometry involving the N, N and O atoms of L and an O atom of acetate anion. The four bond distances are nearly equal. Kinetics of oxidation of dopamine using molecular oxygen as an oxidant and [Cu(L)CH3COO] as catalyst has also been studied spectrophotometrically. The complex catalyses the oxidation of dopamine to dopachrome or aminochrome in methanol

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

36-42A 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 c-axis. The [Ni(L)2].(NO3)2 complex has been utilized for the oxidation for 2-amino-4-tert-butylphenol to 4-tert-butyl-o-benzoquinone in the presence of hydrogen peroxide and the average rate of reaction is calculated to be 63×10–7 M min–1. The presence of externally added acetate ion tends to inhibit the rate of reaction