Organogermanium polymers prepared from s-indacene and carbodiimide compounds

The synthesis of bis-organogermanium compounds including s-indacene structure was described and showed the formation of one type of trans isomer characterized by spectroscopic methods. In the same way, the digermyl-s-indacene dichlorides were prepared and structural characterizations confirmed the unique formation of trans isomers. These digermyl-s-indacene dichlorides were used as monomers in a polymerization reaction in order to prepare poly(germyl-s-indacenes) and poly(germyl-s-indacene carbodiimides). However, only the products obtained from tetraalkyl-s-indacene reached high molecular weight, probably due to a minor steric hindrance compared to the hexaalkyl-s-indacene. Thermal degradation only starts from 250°C for poly(germyl-s-indacene carbodiimides) and from 350°C for poly(germyl-s-indacenes). The structures of the first digermyl-s-indacene dichlorides were determined by X-ray analysis, confirming that the chlorogermyl groups are located in trans positions. Copyright © 2012 John Wiley & Sons, Ltd.