Journal article

Publication year: 2003

Pages: 1197-1205

Journal: European Journal of Inorganic Chemistry

Volume number: 2003

Issue number: 6

ISSN: 1434-1948

DOI Link: https://doi.org/10.1002/ejic.200390155

Publisher: Wiley-VCH Verlag

Abstract: 
The ligand alpha,alpha'-bis{bis[1-(1'-methyl-2'-benzimidazolyl)-methyl] amino}-m-xylene (L-55) forms the complexes [Cu-2(I)(L-55)(MeCN)(2)](PF6)(2) (1) and [Cu-2(II)(L-55)(OMe)(2)][ClO4](2) (2), in which an extremely weak axial amine interaction is imposed by the small five-membered benzimidazole chelating ring units. This structural feature has been characterized by Xray crystal structure determination. In 1, the Cu-I centers are three-coordinate with ligation from two benzimidazolyl and one acetonitrile N-donors, in a slightly distorted trigonal arrangement. In 2, each Cull center has a distorted square-planar geometry and coordinates to the benzimidazolyl N atoms and the bridging methoxy groups in the basal positions, with a much weaker interaction with the tertiary amine N in an apical position. These structural features affect the reactivities of the copper(I)- and copper(II)-L-55 complexes toward dioxygen and hydrogen peroxide, respectively. [Cu-2(I)(L-55)(NleCN)(2)](2+) does not produce a stable peroxo complex, but undergoes an irreversible oxidation to copper(II) species, while [Cu-2(II)(L-55)(H2O)(2)](4+) reacts slowly with hydrogen peroxide to undergo regiospecific hydroxylation of the ligand at one benzylic carbon atom, which causes decomposition of the complex. [Cu-2(L-55)(H2O)(2)](4+) is easily converted into its bis(mu-hydroxo) adduct [Cu-2(L-55)(OH)(2)](2+). This pH-driven equilibrium was monitored by paramagnetic H-1 NMR spectroscopy, and the solution magnetic properties of the complexes were determined by the Evans susceptibility method. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).

Harvard Citation style: Battaini, G., Casella, L., Gullotti, M., Monzani, E., Nardin, G., Perotti, A., et al. (2003) Structure and Reactivity Studies on Dinuclear Copper Complexes of the Ligand α,α′‐Bis{bis[1‐(1′‐methyl‐2′‐benzimidazolyl)methyl]amino}‐m‐xylene, European Journal of Inorganic Chemistry, 2003(6), pp. 1197-1205. https://doi.org/10.1002/ejic.200390155

APA Citation style: Battaini, G., Casella, L., Gullotti, M., Monzani, E., Nardin, G., Perotti, A., Randaccio, L., Santagostini, L., Heinemann, F., & Schindler, S. (2003). Structure and Reactivity Studies on Dinuclear Copper Complexes of the Ligand α,α′‐Bis{bis[1‐(1′‐methyl‐2′‐benzimidazolyl)methyl]amino}‐m‐xylene. European Journal of Inorganic Chemistry. 2003(6), 1197-1205. https://doi.org/10.1002/ejic.200390155