Metalloid cluster compounds of germanium:: A novel class of germanium cluster compounds of formulae GenRm (n>m)

Metalloid cluster compounds of germanium of the general formulae GenRm with n > m, where in addition to ligand bound germanium atoms, naked germanium atoms are also present, represent a novel class of cluster compounds in germanium chemistry. Due to the fact that the naked germanium atoms inside these clusters can be assigned an oxidation state of 0, the average oxidation state of the germanium atoms inside such metalloid cluster compounds is between 0 and 1. Thus these cluster compounds can be seen as on the way to elemental germanium and therefore interesting properties are expected for these compounds which might give impact to nanotechnology. During the last 3 years, different synthetic strategies have been introduced for the synthesis of such novel cluster compounds featuring unexpected structural and bonding properties. In this article, an account is given to the first developments in this novel field in germanium chemistry in which special attention is given to structural features and bonding properties. (c) 2006 Elsevier B.V. All rights reserved.