| Abstract
| - The reaction of Cu(ClO4)2·6H2O with the new tripodal ligand HNpy2pz (N-bis[(pyridin-2-yl)methyl][1H-pyrazol-3-yl)methyl]amine) in the presence of 1 equiv of triethylamine results in the formation of a doubly pyrazolato-bridgeddicopper(II) complex, [Cu(Npy2pz)]2(ClO4)2·2CH3CN (1). The crystal structure of 1 was determined by X-raycrystallography and was found to consist of two nearly identical discrete dinuclear molecules with bis(pyrazolato)bridges. The copper(II) ion has a trigonal bipyramid geometry achieved by the coordination of an aliphatic nitrogen,two pyridine moieties, and two pyrazolato nitrogens. Variable temperature-dependent magnetic data show thatantiferromagnetic interactions operate in 1 as a result of the binding angle of the pyrazolato bridge. In solution, thestability of the dinuclear cation, [Cu(py2pz)]22+, is highly dependent on the concentration, as indicated by ESI-MS,ligand field, cyclic voltammetry, EPR, and 1H NMR studies.
- The reaction of Cu(ClO4)2·6H2O with HNpy2pz in the presence of 1 equiv of triethylamine results in the formation of a dinuclear pyrazolato-bridged copper(II) complex, [Cu(Npy2pz)]2(ClO4)2·2CH3CN. The complex is the first example of a double pyrazolato-bridged complex in which the copper(II) ion has a trigonal bipyramid geometry achieved only by the ligand conformation.
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