Preparation and Precise Structural Determination of a Second Ga84 Cluster Compound. A First Hint for Cluster Doping and Its Fundamental Consequences in the Field of Chemistry and Physics of Nanoscaled Metalloid Cluster Material

The Ga84R20^4- [R = N(SiMe3)2] species, which represents the largest metalloid cluster entity structurally characterized so far, has been electronically and topologically modified: Via changing the redox potential of the reaction solution, crystals different from those containing the Ga84R20^4- anion can be isolated, featuring similar Ga84R20^3-entities. An accurate crystal structure analysis via synchrotron radiation is presented, which might be the first step toward an understanding of the metallic conductivity and superconductivity of the Ga84R2o^4- cluster compound, physical properties which are singular in the field of metalloid clusters so far.