Syntheses and Structural, Physical, and Theoretical Studies of the Novel Isostructural Mo9 Cluster Compounds Ag2.6CsMo9Se11, Ag4.1ClMo9
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- 作者：Patrick Gougeon ; Michel Potel ; and Ré ; gis Gautier
- 刊名：Inorganic Chemistry
- 出版年：2004
- 出版时间：February 23, 2004
- 年：2004
- 卷：43
- 期：4
- 页码：1257 - 1263
- 全文大小：191K
- 年卷期：v.43,no.4(February 23, 2004)
- ISSN：1520-510X
文摘
The new isostructural compounds Ag2.6CsMo9Se11 (1) and Ag4.1ClMo9Se11 (2) were prepared by solid-state reactionin evacuated sealed silica tubes at 1200 
C and 860 C, respectively. By topotactic reduction-oxidation reactionof Ag4.1ClMo9Se11 with I2, we also obtained the metastable compound h-Mo9Se11 (3). The three compounds crystallizein the hexagonal space group P63/m, Z = 2, (1) a = 10.0472(2) Å, c = 11.9548(2), (2) a = 10.0321(2) Å, c =11.8734(2) Å, and (3) a = 9.4204(2) Å, c = 12.1226(2) Å. Their crystal structures were determined from single-crystal X-ray diffraction data and consist of interconnected Mo9Se11 units forming an original and unprecedentedthree-dimensional framework in which large tunnels are occupied randomly by a part of the Ag+ and the Cl- ionsin 2 and the Cs+ ions in 1, the remaining Ag+ in 1 being localized in mirror planes around the 3-fold axis. First-principle calculations allow the understanding of the variation of the atomic distances. Electrical resistivitymeasurements carried out on single crystals of Ag2.6CsMo9Se11 and Ag4.1ClMo9Se11 in which the number of electronsper Mo9 cluster is different indicate that the former is semiconducting whereas the latter is semimetallic.
C and 860 C, respectively. By topotactic reduction-oxidation reactionof Ag4.1ClMo9Se11 with I2, we also obtained the metastable compound h-Mo9Se11 (3). The three compounds crystallizein the hexagonal space group P63/m, Z = 2, (1) a = 10.0472(2) Å, c = 11.9548(2), (2) a = 10.0321(2) Å, c =11.8734(2) Å, and (3) a = 9.4204(2) Å, c = 12.1226(2) Å. Their crystal structures were determined from single-crystal X-ray diffraction data and consist of interconnected Mo9Se11 units forming an original and unprecedentedthree-dimensional framework in which large tunnels are occupied randomly by a part of the Ag+ and the Cl- ionsin 2 and the Cs+ ions in 1, the remaining Ag+ in 1 being localized in mirror planes around the 3-fold axis. First-principle calculations allow the understanding of the variation of the atomic distances. Electrical resistivitymeasurements carried out on single crystals of Ag2.6CsMo9Se11 and Ag4.1ClMo9Se11 in which the number of electronsper Mo9 cluster is different indicate that the former is semiconducting whereas the latter is semimetallic.