Oxidation of [Ge 9 {Si(SiMe 3 ) 3 } 3 ] - with LnI 3 (Ln = Eu, Sm, Yb): Isomerism of Metalloid Germanium Clusters.

The oxidation of K[Ge 9 (Hyp) 3 ] (Hyp = Si(SiMe 3 ) 3 ) with lanthanide triiodides LnI 3 (Ln = Eu, Sm, Yb) leads to the formation of novel clusters with a Ge 18 -core isolated as a co-crystallizate of Ge* 18 (Hyp) 6 ( 1a ) and Ge 18 (Hyp) 5 (Si(SiMe 3 ) 2 )(SiMe 3 ) ( 1b ). Clusters 1a and 1b differ distinctly from the known cluster Ge 18 (Hyp) 6 ( A ), which has been found earlier in the reaction of K[Ge 9 (Hyp) 3 ] with FeCl 2 and now identified as an intermediate product in the production of compounds 1a and 1b . These three compounds A , 1a , and 1b are thus structural isomers being the first example of genuine isomerism in metalloid main-group cluster compounds.