Dedicated to Professor Helge Willner on the occasion of his 60th birthdayDepicting the electronic structure of compounds clearly is one of the most difficult tasks in chemistry. For molecular moieties of identical atoms (clusters) many models have been developed which are often limited to specific compound classes. Gaseous cluster species, for example, as ions in mass spectrometry, could suitably be described with the Jellium model because the filling of electronic shells in these species, like in atoms, with specific numbers of valence electrons can explain their different stabilities.[ (Figure 1). [6,7] The rules of Wade, [9] Mingos, [10] Zintl, [11] Klemm, [11] and Jemmis, [12] for example, were useful in the explanation of bonding found in the structurally characterized cluster species of boranes or Zintl ions. But these models can only rudimentarily be applied to larger cluster species of identical metal atoms [13] (for example [Al 77 R 20 ] 2À ). The topological similarity in the arrangement of metal atoms of these clusters with the one found in elements was our motivation for terming such species metalloid or even elementoid clusters. [14,15] Recently King and Schleyer could show that some of the mentioned rules can in fact be used in the bond description of such a metalloid [Ga 22 R 8 ] cluster (Figure 1). [16] Herein, we attempt to demonstrate that the Jellium model can also contribute to the understanding of several metalloid clusters. These considerations are now possible for the first time because a unique possibility of comparison for a single element is given by a {Ga 23 } cluster presented here and four further differently structured {Ga 22 } clusters, [17] as well as a recently reported {Ga 24 } cluster [8] (Figure 1). The capacity of the Jellium model to describe the bonding of such clusters can be assessed based on experimental structural data. For the discussion on the bonding situation special attention will be given to the atomic volumes.At À78 8C a suspension of LiN(SiMe 3 ) 2 in toluene was treated with a small excess of a metastable GaCl solution in toluene/ether (3:1) that was obtained by the joint condensation of GaCl molecules formed at about 900 8C and the solvent mixture.[18] After processing the reaction solution (see the Experimental Section) black rhombus-shaped crystals of the title compound [Ga 23 {N(SiMe 3 ) 2 } 11 ] (1) were obtained. [19] Thus, formally, disproportionation and subsequent or simultaneous metathesis of GaCl occurred in the reaction.The result of the X-ray structural analysis of 1 is presented in Figure 2 a.[20] A body-centered naked {Ga 12 } core is present in 1 and is surrounded by 11 GaR moieties. The most important structural data are shown in the caption of Figure 2, where 1 is contrasted with the similar cluster [Ga 22 {N(SiMe 3 ) 2 } 10 ] 2À (2).[21] Both clusters contain a central Ga atom uncommonly surrounded by 11 further "naked" (that is, not ligand-bearing) gallium atoms.[22] The ligand shell of 1 is formed by 11 GaR moieties, and that of 2 is for...

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The exceptionally long (4.5 nm) monodisperse polycyclic aromatic hydrocarbon 1 contains 29 condensed five‐and six‐membered rings. Since the dodecyl chains make this extended, flat (tabular) molecule unusually soluble in common organic solvents, it can be readily characterized. Compound 1 can be reduced to the octaanion within a relatively small potential range, and the tetraction that forms on oxidation is stable for several seconds.

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