No abstract

A "naked" aluminum atom links two aluminum tetrahedra in the [Al(7){N(SiMe(3))(2)}(6)](-) ion (see picture), which results from the reaction of a metastable AlCl solution with LiN(SiMe(3))(2) and crystallizes with [Li(OEt(2))(3)](+) as cation. This unique structure among molecular metal atom clusters represents a small but characteristic section of cubic close-packed aluminum.

A metastable AlCl solution obtained by co-condensation of the high-temperature molecule AlCl and a mixture of toluene/diethyl ether reacted with SiCp* 2 or SiCl 4 /AlCp*, giving a unique SiAl 14 cluster species that bears six Cp* ligands protecting the compound from disproportionation and formation of the bulk material (elemental Al or an Si/Al alloy). The structure of the SiAl 14 core represents a section of the bodycentered packing where a Si atom resides in the center of an Al cube. Each of the six faces of the cube is capped by an additional Al(η 5 Cp*) moiety. This cluster compound was investigated by mass spectrometry, X-ray diffraction, 27 Al NMR spectroscopy, and ab initio theory. The solid-state structure contains minor amounts of molecules with additional Cl atoms bonded to the Al atoms at the corners of the cube, and the presence of Cl-containing molecules in the crystal is rationalized on basis of the suggested reaction path.

3 SiCl. According to X-ray structure analyses, the ditrielanes contain two planar groups R 2 EE which are orthogonal to each other (R = R*; angle REER ca. 90°) or nearly orthogonal (R = RЈ; angle REER ca. 80°). All compounds are deeply colored. The λ max value of the visible absorption shifts with increasing atomic number of E and with the increasing angle between the R 2 EE planes to longer wavelengths (ruby R− besides the mentioned ditrielanes − are presented.In fact, except for the compounds dealt with in this publication, only three other examples of silyl-ditrielanes, namely [(Me 3 Si) 3 Si] 4 E 2 with E ϭ Ga, [9] In, [10] Tl [11] have been published to date. On the other hand, some organyland aminyl-ditrielanes R 4 E 2 are known with R ϭ

A disproportionation process of a metastable AlCl solution with a simultaneous ligand exchange-Cl is substituted by N(SiMe(3))(2)-leads to a [Al(69)[N(SiMe(3))(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 [Al(77)N(SiMe(3))(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.