Novel Linear Transition Metal Clusters of a Heptadentate Bis--diketone Ligand
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- 作者：Guillem Aromí ; Patrick Gamez ; J. Krzystek ; Huub Kooijman ; Anthony L. Spek ; Elizabeth J. MacLean ; Simon J. Teat ; Harriott Nowell
- 刊名：Inorganic Chemistry
- 出版年：2007
- 出版时间：April 2, 2007
- 年：2007
- 卷：46
- 期：7
- 页码：2519 - 2529
- 全文大小：265K
- 年卷期：v.46,no.7(April 2, 2007)
- ISSN：1520-510X
文摘
The synthesis and the structure of the new potentially heptadentate ligand 1,3-bis-(3-oxo-3-(2-hydroxyphenyl)-propionyl)-2-methoxybenzene (H5L) is described. The reaction in pyridine or DMF of this ligand with various M(AcO)2salts (M = NiII, CoII, MnII) leads to very different products depending on the metal. Thus, the dinuclear complexes[M2(H3L)2(py)4] (M = NiII, 1; CoII, 2) or the linear zigzag tetranuclear clusters [Mn4(H2L)2(AcO)2(py)5] (3) and [Mn4(H2L)2(AcO)2(dmf)4] (4) have been synthesized and characterized crystallographically. Slow oxidation of complex 3leads to the formation of the novel mixed-valence linear complex [Mn3(HL)2(py)6] (5), displaying an unprecedentedasymmetric MnIIIMnIIIMnII topology. The coordination geometry of complexes 1 to 5 has been analyzed and discussedby means of continuous shape measures. Magnetic measurements of 3 and 5 demonstrate that the metals withinthese complexes weakly interact magnetically with coupling constants of J1 = -1.13 cm-1 and J2 = -0.43 cm-1(S = 0) for complex 3 and J1 = -5.4 cm-1 and J2 = -0.4 cm-1 (S = 5/2) for complex 5 (using the H = -
2JijSiSjconvention). These results are consistent with X-band EPR measurements on these compounds.
2JijSiSjconvention). These results are consistent with X-band EPR measurements on these compounds.