Rsc_cc_c1cc13937a 1..3

Mixed valence is the basis of essential physicochemical properties of compounds such as colour, electron transfer. By analyzing the nature of the bonding of the components the electronic properties of the materials can be better understood and influenced. This phenomenon has been known for a long time and broadly used in transitionmetal chemistry, however for main group compounds it has been explored less. Here, for example the large metalloidal clusters of group 13 elements and those of group 14 elements are known for homoatomic cage systems. For heteroatomic arrangements, 13/15 compounds have been intensively investigated due to the important role for semiconducting materials. These compounds and also the rarely studied group 14/15 compounds are usually electron precise. For the latter, there are only known a few compounds with tin atoms in two different formal oxidation states, e.g. [Sn8(PSiiPr3)6Cl2]. 7 The only two Ge/P systems known in the literature are the cage compound [(R2Ge)6P4] (R = CH3, C2H5), which was synthesized by thermal condensation of R2Ge(PH2)2, 8 and the hexagonal prismatic [Ge6(PSiiPr3)6] obtained from the reaction of GeCl2(diox)2 with Li2PSiiPr3. 7