Inorganic Chemistry, Vol.36, No.14, 2944-2949, 1997
Synthesis and Coordination Chemistry of the bis(Imidazole) Ligand, bis(1-Methyl-4,5-Diphenylimidaz-2-Oyl)(Benzyloxy)Methane
The synthesis and characterization of the new imidazole ligand bis(1-methyl-4,5-diphenylimidaz-2-oyl)(benzyloxy)methane (BimOBz) and its copper(II) complexes [Cu(BimOBz)(2)][BF4](2) . 2H(2)O (1 . 2H(2)O), [Cu(BimOBz)(NO3)(2)]. CH2Cl2 (2 . CH2Cl2) and [Cu(BimOBz)Cl-2]. 2EtOH (3 . 2EtOH) are presented. The X-ray crystallographic parameters determined are as follows : 1.solv (solv petroleum ether) C84H66N8B2CuF8O2, 1456.65, monoclinic space group (P2(1)/a), a = 20.862(8) Angstrom, b = 19.110(5) Angstrom, c = 22.452(9) Angstrom, beta = 110.09(3)degrees, Z = 4, R = 0.129, and R-w = 0.139. 2 . CH2Cl2, C41H36N6Cl2O7, 859.22, monoclinic space group (P2(1)/c), a = 9.748(1) Angstrom, b = 14.157(5) Angstrom, c = 17.209(2) Angstrom, beta = 103.709(8)degrees, Z = 4, R = 0.066, and R-w = 0.087. 3 . 2EtOH, C44H38N4Cl2CuO2, 789.26, monoclinic space group (P2(1)/a), a = 17.171(5) Angstrom, b = 13.988(3) Angstrom, c = 17.897(5) Angstrom, beta = 112.52(2)degrees, Z = 4, R = 0.084, and R-w = 0.092. The geometry at these Cu-II centers is distorted tetrahedral in 1 and 3 and essentially square-planar in 2, and this difference is reflected in their EPR spectra, especially the value of A(z); 1 (solid, g(x) = 2.06, g(y) = 2.13, g(z) = 2.30, A(z) = 94 x 10(-4) cm(-1)), 3 (CH2Cl2, 77 K, g(x) = g(y) = 2.06, g(z) = 2.37, A(z) = 75 x 10(-4) cm(-1)), 2 (solid, g(x) = g(y) = 2.06, g(z) = 2.28, A(z) = 169 x 10(-4) cm(-1)). 1 displays a reversible, one-electron Cu-II/Cu-I couple in CH2Cl2 and MeCN at potentials of +0.62 and +0.49 V vs SCE, respectively.
Keywords:ERYTHROCYTE SUPEROXIDE-DISMUTASE;CRYSTAL-STRUCTURE;COPPER(II) COMPLEXES;MOLECULAR-STRUCTURES;ELECTRONIC-SPECTRA;THIOETHER;HEMOCYANIN;PROTEINS;OXIDASE;MODEL