Oligoorganogermanes: Interplay between Aryl and Trimethylsilyl Substituents.

Derivatives of main group elements containing element-element bonds are characterized by unique properties due to σ-conjugation, which is an attractive subject for investigation. A novel series of digermanes, Ar 3 Ge-Ge(SiMe 3 ) 3 , containing aryl (Ar = p -C 6 H 4 Me ( 1 ), p -C 6 H 4 F ( 2 ), C 6 F 5 ( 3 )) and trimethylsilyl substituents, was synthesized by the reaction of germyl potassium salt, [(Me 3 Si) 3 GeK*THF], with triarylchlorogermanes, Ar 3 GeCl. The optical and electronic properties of such substituted oligoorganogermanes were investigated spectroscopically by UV/vis absorption spectroscopy and theoretically by DFT calculations. The molecular structures of compounds 1 and 2 were studied by XRD analysis. Conjugation between all structural fragments (Ge-Ge, Ge-Si, Ge-Ar, where Ar is an electron-donating or withdrawing group) was found to affect the properties.