1,2-Bis(ferrocenyl)digermene: A d−π Electron System Containing a GeGe Unit

The synthesis and structural analysis of the 1,2-bis­(ferrocenyl)­digermene (E)-Tip­(Fc)­GeGe­(Fc)­Tip (Tip = 2,4,6-triisopropylphenyl, Fc = ferrocenyl), a stable crystalline compound, is reported. In this digermene, two ferrocenyl d electron systems are bridged by a GeGe π spacer. As is evident from X-ray crystallographic, spectroscopic, and electrochemical analysis, this 1,2-bis­(ferrocenyl)­digermene shows effective d−π interaction and the GeGe π bond is stable in the solid state. The GeGe double bond is cleaved at elevated temperatures in the presence of butadiene, with concomitant loss of the π conjugation in the molecule.