Inorganic Chemistry, Vol.40, No.19, 4830-4838, 2001
Synthesis and characterization of an Al-69(3-) cluster with 51 naked Al atoms: Analogies and differences to the previously characterized Al-77(2-) cluster
A disproportionation process of a metastable AlCl solution with a simultaneous ligand exchange-Cl is substituted by N(SiMe3)(2)-leads to a [Al-69{N(SiMe3)(2)}(18)](3-) cluster compound that can be regarded as an intermediate on the way to bulk metal formation. The cluster was characterized by an X-ray crystal structural analysis. Regarding its structure and the packing within the crystal, this metalloid cluster with 4 times more Al atoms than ligands is compared to the [Al77N(SiMe3)(2)}(20)](2-) cluster that has been published four years ago. Although there is a similar packing density of the Al atoms in both clusters as well as in Al metal, the X-ray structural analysis shows significant differences in topology and distance proportions. The differences between these-at a first glance almost identical-Al clusters demonstrate that results of physical measuring, e.g., of nanostructured surfaces which carry supposedly identical cluster species, have to be interpreted with great caution.