Mn~2.4Mo6O9: First Example of Empty Twin Chains of Edge-Sharing M6 Octahedra in Transition Metal Cluster Chemistry
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- 作者：Nicolas Barrier ; Patrick Gougeon ; Richard Retoux ; and Henri Leligny
- 刊名：Inorganic Chemistry
- 出版年：2003
- 出版时间：March 10, 2003
- 年：2003
- 卷：42
- 期：5
- 页码：1734 - 1738
- 全文大小：156K
- 年卷期：v.42,no.5(March 10, 2003)
- ISSN：1520-510X
文摘
The novel ternary reduced molybdenum oxide Mn~2.4Mo6O9 has been synthesized by solid-state reaction at 1400
C for 96 h in sealed molybdenum crucibles. Electron diffraction studies showed that Mn~2.4Mo6O9 presents acomplex crystal structure with a 3d incommensurate modulation. The average crystal structure was determined ona single-crystal by X-ray diffraction in the orthorhombic space group Pnma with the following lattice parameters:a = 16.4824(2) Å, b = 2.8273(2) Å, c = 17.3283(2) Å, Z = 4. The Mo network consists of empty twin chains oftrans-edge-sharing octahedra that occur for the first time in a solid-state compound. The Mo-Mo distances withinthe chains range from 2.62 to 2.92 Å, and the Mo-O distances from 1.99 to 2.17 Å as usually observed in thereduced molybdenum oxides. Single-crystal resistivity measurements show that Mn~2.4Mo6O9 is metallic between4.2 and 300 K. The magnetic susceptibility data indicate paramagnetic behavior due to the Mn2+ moment at hightemperatures with a weak ferromagnetic behavior below 80 K.
C for 96 h in sealed molybdenum crucibles. Electron diffraction studies showed that Mn~2.4Mo6O9 presents acomplex crystal structure with a 3d incommensurate modulation. The average crystal structure was determined ona single-crystal by X-ray diffraction in the orthorhombic space group Pnma with the following lattice parameters:a = 16.4824(2) Å, b = 2.8273(2) Å, c = 17.3283(2) Å, Z = 4. The Mo network consists of empty twin chains oftrans-edge-sharing octahedra that occur for the first time in a solid-state compound. The Mo-Mo distances withinthe chains range from 2.62 to 2.92 Å, and the Mo-O distances from 1.99 to 2.17 Å as usually observed in thereduced molybdenum oxides. Single-crystal resistivity measurements show that Mn~2.4Mo6O9 is metallic between4.2 and 300 K. The magnetic susceptibility data indicate paramagnetic behavior due to the Mn2+ moment at hightemperatures with a weak ferromagnetic behavior below 80 K.