Synthesis, characterization and magnetic behaviour of tetra-μ3-fluorododecakis(5-methylpyrazole-N2)tetrametal(II) tetrakis(tetrafluoroborates)
1981; Elsevier BV; Volume: 51; Linguagem: Inglês
10.1016/s0020-1693(00)88311-5
ISSN1873-3255
AutoresR. W. M. TEN HOEDT, J. Reedijk,
Tópico(s)Ferrocene Chemistry and Applications
Resumo3(5)-Methylpyrazole (3(5)-MPZ) was found to induce tetrafluoroborate decomposition upon the reaction with M(BF4)2·aq salts, yielding fluoride containing compounds, analysing as MF(5-MPZ)3(BF4). For M = Cd and Mn this reaction proceeds at room temperature, while for M = Co and Ni higher reaction temperatures (up to 80 °C) have to be used. According to IR, UV and EPR spectroscopy and X-ray powder diagrams a tetrameric structure is proposed in correspondence to the known structure of [Co4F4(N-ethylimidazole)12](BF4)4. The ligand 3(5)-MPZ is believed to bind to the metals with the methyl substituent in the 5-position. Magnetic susceptibility studies down to 2 K indicate weak antiferromagnetic interaction between the metal ions in the cluster. The magnitude of the exchange parameter for the Co-compound (J/k≈ − 7 K) is comparable to the one found previously for Co4F4(N-ethylimidazole)12(BF4)4.
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