Bisvinylated [ R –Ge 9 –Ge 9 – R ] 4– Cluster Dimers

The syntheses, crystal structures, and NMR and Raman spectroscopic characterization of two compounds with a new member of the organically functionalized dimeric Ge 9 –Ge 9 polyanion [ R –Ge 9 –Ge 9 – R ] 4– with R = CH=CH 2 are presented. [K([2.2.2]crypt)] 4 [(CH 2 =CH)–Ge 9 –Ge 9 –(CH=CH 2 )] · 1.76 en ( 1 ) was synthesized either at elevated temperature by the reaction of K 4 Ge 9 and bis(trimethylsilyl)acetylene in ethylenediamine or at ambient temperature in the presence of Pt(PPh 3 ) 4 . [K(18crown‐6)] 4 [(CH 2 =CH)–Ge 9 –Ge 9 –(CH=CH 2 )] · 4 en ( 2 ) was obtained from the prefabricated monomeric bisvinylated Ge 9 cluster [Ge 9 (CH=CH 2 ) 2 ] 2– and an ethylenediamine solution of the intermetallic compound K 4.79 Co 0.79 Sn 9 . The reductive cleavage of one or two vinyl groups from [Ge 9 (CH=CH 2 ) 2 ] 2– – a prerequisite for the latter reaction – could be shown by reacting a solution of the divinylated [Ge 9 (CH=CH 2 ) 2 ] 2– anion in liquid ammonia with elemental potassium, which resulted in the formation of the ligand‐free Ge 9 4– cluster in the new compound [K 5 (OH)]Ge 9 (NH 3 ) 11 ( 3 ).