Germylene, germanium polymers

The electronic properties of germanium have led to an interest in incorporating the element into extended polymeric chains due to the intrinsic properties of the polymers themselves or in their use as precursors for material synth-esis. Catalytic co-polymerization of the germylene Ge[N(SiMe3)2]2 with various substituted acetylenes leads to... 

The oxidation-reduction route was also used to prepare copolymers 53 of bis[bis(tri-methylsilyl)amido]germanium and acetylene derivatives130 (Scheme 27). Rhodium compounds such as [Rh(norbornadiene)Cl]2 were used as catalysts. In contrast to other polymers prepared from germylenes, the monomer-to-monomer ratio was not regular. Relatively low molecular weight polymers 53 (Mn = 1 x 103-104) were isolated. 

Kobayashi prepared a novel germanium-containing polymer, poly(germanium enolate), by reaction of a divalent germanium compound, germylene, with a cyclic a, -unsaturated ketone in the presence of a catalytic amount of a lithium compound (Scheme 11.65) [91[. 

Shoda, S., Iwata, S., Yajima, K., Yagi, K., Ohnishi, Y. and Kobayashi, S. (1997) Synthesis of germanium enolate polymers from germylene monomers. Tetrahedron 53,15281-15295. 

Organogermanium polymers were prepared by Kobayashi and coworkers via the reaction of a germylene (175) with acetylene monomers (176) in the presence of a rhodium catalyst (Scheme 43). Copolymer 177 incorporated a larger ratio of polyacetylene units than germanium units in the backbone. 

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