[Ga22(PtBu2)12]: Diversity in the Arrangement of 22 Gallium Atoms—A Unique Case in the Field of Metalloid Clusters?
✍ Scribed by Jochen Steiner; Gregor Stößer; Hansgeorg Schnöckel
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 164 KB
- Volume
- 43
- Category
- Article
- ISSN
- 0044-8249
No coin nor oath required. For personal study only.
✦ Synopsis
on the occasion of his 70th birthday
With the formation of three different Ga 22 frameworks in metalloid clusters, the element gallium assumes a unique position in the field of metal clusters, [1] since to our knowledge, structural isomers of large metalloid clusters are not known to date for any other metal. Here we report an additional structural variation in the arrangement of 22 gallium atoms, in which for the first time an icosahedral Ga 12 core is retained despite extensive reduction of the Ga 22 framework (average oxidation number 0.55). We have previously achieved low oxidation numbers for Ga 22 clusters only when gallium-centered arrangements were present in the cluster core (oxidation number 0.36, Figure 1): [Ga 22 R 8 ] (1) with R = SitBu 3 (1 a), [2] Si(SiMe 3 ) 3 (1 b), [3] and Ge(SiMe 3 ) 3 (1 c) [4] as well as [Ga 22 R 10 ] 2À (2) with R = N(SiMe 3 ) 2 ; [5] the coordination numbers of the central Ga atoms are 13 for 1 and 11 for 2. In contrast, in the case of the only previously obtained Ga 22 cluster with an icosahedral Ga 22 core (without a central Ga atom), [Ga 22 {N(SiMe 3 ) 2 } 10 Br 10 ] 2À (3), [6] the average oxidation number of 0.82 is not very different from that of the GaX starting material. This is also true for the first polyhedral gallium subhalide [Ga 24 X 22 ] (4) [7] (average oxidation number 0.92), which can be viewed as a common precursor (possibly in a slightly modified form, such as [Ga 22 X 20 ], which is analogous to the well-known [Al 22 X 20 ] [8] ) for the numerous