New Vinylgermanium Derivatives of Silsesquioxanes and Their Ruthenium ComplexesSynthesis, Structure, and Reactivity

New
vinylgermanium cubic derivatives of silsesquioxanes (i.e.,
monovinylhepta­(alkyl, phenyl)­germasilsesqiuoxanes and (dimethylvinylgermoxy)­heptaisobutylsilsesquioxanes)
were synthesized and characterized by spectroscopic methods. The first
ruthenium–germasilsesquioxyl complexes were also prepared via
stoichiometric reaction of RuHCl­(CO)­(PPh3)3 with
the above-mentioned vinylgermanium derivatives of silsesquioxanes,
and their structures were determined by spectroscopic and X-ray analyses.
The initial ruthenium complex as well as the above-mentioned Ge–Ru
complexes were tested as catalysts, in the germylative coupling with
olefins, and proved to be active in the case of (dimethylvinyl)­germoxyheptaisobutylsilsesquioxane
but showed no activity toward vinylgermasilsesquioxanes. A general
mechanism for the germylative coupling of the two vinylgermanium derivatives
of silsesquioxanes is presented.