Lead-silicon polymers mechanism

Typical of all carbosilane and carbosiloxane polymerizations is the fact that the trans stereochemistry predominates over the cis with respect to the olefin that is in the backbone. This trans arrangement arises from the polymerization mechanism leading to the connection of olefin units. This is observed to be true, not only for silicon polymers, but for all ADMET polymers made to this point, regardless of whether functionality is present in the backbone. 

---