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Ring‐opening polymerization of strained cyclotetrasilanes as a new route towards well defined polysilylenes
Author(s) -
Cypryk M.,
Chrusciel J.,
Fossum E.,
Matyjaszewski K.
Publication year - 1993
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19930730116
Subject(s) - triflic acid , regioselectivity , monomer , ring (chemistry) , chemistry , chemoselectivity , ring opening polymerization , polymerization , silanes , polymer chemistry , counterion , catalysis , bromide , stereoselectivity , organic chemistry , polymer , ion , silane
Ring‐opening polymerization of cyclic silanes is described as a new synthetic route to well defined high molecular weight polysilylenes (polysilanes). Strained cyclotetrasilanes with phenyl and methyl substituents at each Si atom in the four‐membered ring are prepared by partial dephenylation of octaphenylcyclotetrasilane with triflic acid and the subsequent treatment with methylmagnesium bromide. Chemoselectivity, regioselectivity and stereoselectivity of monomer synthesis is discussed in detail. In addition to classic anionic initiators for the ring‐opening process, new catalysts and initiators based on transition metals (Cu, Pd, Pt) are described. They provide much better control of the microstructure than systems with Li + counterion.