Elementoid clusters

In a metalloid cluster [2] more metal-metal bonds than metal-ligand bonds are involved, which means n > r. The largest structurally characterized compounds of this type contain 77 A1 or 84 Ga atoms, respectively [3, 4], Metal-metal bonds dominate these clusters and the framework of the resulting metal-metal bonds exhibits a geometry similar to the bulk metal itself. With respect to the Greek word ei8o< (idea, prototype) the suffix -oid indicates that the bulk metal element is actually visible in the metal atom core of the metalloid or more generally, elementoid clusters. 

Despite this, proven rules for boron clusters can be applied to the smaller metalloid Al, Ga, and In clusters with certain additional assumptions, as recent DFT calculations have shown [87]. In addition, counting rules for smaller Ga and Al metalloid clusters have been developed [123], which will, however, probably not be transferable to the larger clusters. Therefore the first assignment principle presented here for the larger metalloid clusters incorporates the structures of the elements in the various modifications, which means that the metalloid or elementoid clusters are described as nanostructured element modifications. 

Mixed ligated/naked-atom clusters, which Schnockel has depicted as elementoid or metalloid, are clusters with internal as well as surface atoms. They illustrate the generalized cluster shown in Figure 2.1 and follow neither the borane paradigm nor... 

H. Schnockel and A. Schnepf, Nanostructural Element Modifications Synthesis and Structure of Elementoid Gallium Clusters, in Group 13 Chemistry. From Fundamentals to Applications , ACS Symposium Series 822, eds. P. J. Shapiro and D. A. Atwood, American Chemical Society, Washington, DC, 2002, p. 154. 

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