Stack by Stack: From the Free Cyclopentadienylgermanium Cation Via Heterobimetallic Main-Group Sandwiches to Main-Group Sandwich Coordination Polymers.

Heterobimetallic cationic sandwich complexes [M(μ-Cp)M'Cp] of group 13 (M=Ga, In) and group 14 (M'=Ge, Sn) elements have been prepared as [WCA] salts (WCA=Al(OR ) ; OR =OC(CF ) ). Their molecular structures include free apical gallium or indium atoms. The sandwich complexes were formed in the reactions of [M(HMB)] [WCA] (HMB=C Me ) with the free metallocenes [M'Cp ]. Their structures are related to known stannocene and stannocenium salts; the unprecedented germanium analogues, namely the free germanocenium cation [GeCp] and the corresponding triple-decker complex cation [CpGe(μ-Cp)GeCp] , are described herein. By variation of the reaction conditions, these sandwich complexes can be transformed into the group 13/14 mixed cationic coordination polymer [{In(HMB)(μ-SnCp )} ][WCA] . This polymeric chain motif was also successfully replicated by the synthesis of complexes [{Ga/In(HMB)(μ-FeCp )} ][WCA] containing FeCp as a bridging ligand.