Synthesewege zu (μ1-HO)Zn21-Komplexen

Synthetic Pathways for (μ1-HO)Zn2 Complexes The reactions of the 3-substituted kalium hydrotris(pyrazolyl)1-borates 1c, d (Rtert1-butyl, anisyl) with Zn(ClO4)2 · 6 H2O produce the dinuclear μ1-hydroxo complexes [L3Zn – O(H) – ZnL3](ClO4)3 (2a, b; L5-tert1-butylpyrazole, 5-anisylpyrazole), due to hydrolytic cleavage of the B – N bonds. These and similar complexes (2c, d;5-tert1-butyl-3-methylpyrazole, 5-phenylpyrazole) are also accessible directly from Zn(ClO4)2 · 6 H2O, the substituted pyrazole, and KOH, and in one case (2b; L5-anisylpyrazole) by hydrolytic cleavage of [HB(3-anisylpyrazolyl)3ZnEt] with perchloric acid. With other pyrazole and imidazole ligands, the Zn(ClO4)2/L/KOH reaction produces the simple complexes [ZnL6](ClO4)2 (3a, b; Lpyrazole, 3-methyl-5-phenylpyrazole) and [ZnL4](ClO4)2 (4; L2-methylimidazole). The crystal structures of 2a and 4, each containing tetrahedrally coordinated zinc atoms, have been determined.

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