Synthesis and crystal structures of the polygermanide ammoniates K(4)Ge(9)(center dot)9NH(3), Rb(4)Ge(9)(center dot)5NH(3) and Cs(6)Ge(18)(center dot)4NH(3)

Abstract

The new compounds K4Ge9 center dot 9 NH3 and Rb4Ge9 center dot 5 NH3 were prepared by the extraction of K4Ge9 and Rb4Ge9 with liquid ammonia and characterized by low temperature X-ray structure analysis. They both contain monocapped square antiprismatic Ge-9(4-) anions. Cs6Ge18 center dot 4 NH3 was prepared by the extraction of K2Cs2Ge9 with liquid ammonia in the presence of [(Bu)(3)MeN](Br2I) as an oxidizing agent, and contains a [Ge-9-Ge-9](6-) dimer in which two Ge-9(4-) anions are linked by a single Ge-Ge bond.