Polymer Stereochemistry and Optical Activity

Polymer Stereochemistry and Optical Activity.—Although stereoregular products from carbocation propagations are not common, there are some notable examples, perhaps the most important being the isotactic materials from alkyl vinyl ethers. Recently, novel catalysts based on phosphoryl and thionyl chlorides with vanadium pentoxide have been added to those initiator systems capable of producing stereospecific reactions. 

Definitive work using a range of triphenylmethyl carbocation salts with different anions has shown the importance of the tightness of the growing ion pair and 

Higashimura, O. Kishiro, K. Matsuzaki, and T. Uryu,/. Polymer Sci., Polymer Chem., 1975, 13, 1393. 

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