A structural model for the copper(II) site of Cu-Zn superoxide dismutase: preparation, crystal structure and properties of [Cu(Mebta)(4)(H2O)](ClO4)(2)center dot 0.4 EtOH (Mebta=1-methylbenzotriazole)

Reaction of Cu(ClO4)(2). 6H(2)O with 1-methylbenzotriazole (Mebta) in EtOH yields [Cu(Mebta)(4)(H2O)] (ClO4)(2). 0.4EtOH in ca. 75% yield. The structu re of this salt has been determined by single-crystal X-ray crystallography . Mebta behaves as a monodentate ligand binding through N(3). The metal coo rdination geometry is best described as distorted square pyramidal with the H2O ligand occupying the apical site. The complex was also characterized b y molar conductivity, room-temperature effective magnetic moment and spectr oscopic (i.r., far-i.r., u.v./vis, e.s.r.) studies. The data are discussed in terms of the nature of bonding and known structure. Comparison between t he structural and spectroscopic properties of [Cu(Mebta)(4)(H2O)](ClO4)(2). 0.4EtOH and those of the (CuI)-I-I site of Cu-Zn superoxide dismutase show s that the former can be considered as a fairly good model for the latter.