| Autor: |
S. Fleming, James, L. V. Mann, Karen, M. Couchman, Samantha, C. Jeffery, John, A. McCleverty, Jon, D. Ward, Michael |
| Zdroj: |
Journal of the Chemical Society, Dalton Transactions; June 21, 1998, Vol. 1998 Issue: 12 p2047-2052, 6p |
| Abstrakt: |
Reaction of 3-(2-pyridyl)pyrazole with α,α′-dibromoxylene affords a new tetradentate ligand L having two bidentate pyridyl-pyrazole compartments linked by an o-CH2C6H4CH2 spacer. With CuI, L forms a dinuclear double helicate [Cu2L2][PF6]2 in which both ligands are bridging both pseudo-tetrahedral metal ions, which are 5.05 Å apart. However L does not support a double helical architecture with CuII. Reaction of L with CuCl2 affords [CuLCl][BF4] which is trigonal bipyramidal both in the solid state (by X-ray crystallography) and in solution (by EPR spectroscopy). Reaction of L with Cu(MeCO2)2·H2O affords [Cu2L3][BF4]4 which was characterised by mass spectroscopy and elemental analysis. By analogy with the (known) nickel(II) analogue, this complex has one ligand acting as a bis-bidentate bridge between two {CuL}2+ fragments in which L acts as a terminal tetradentate chelating ligand. Recrystallisation of this afforded a few crystals of the decomposition product [CuL(MeOH)][CuL(SiF6)][BF4]2, which contains trigonal-bipyramidal [CuL(MeOH)]2+ and six-co-ordinate [CuL(SiF6)] fragments, the latter displaying the first known example of the hexafluorosilicate anion acting as a bidentate chelating F,F-donor. |
| Databáze: |
Supplemental Index |
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