POLYMERIZATION OF PHENYLACETYLENE WITH DI-MU-PENTAFLUOROTHIOPHENOLATEBIS(1,5-CYCLOOCTADIENE)RHODIUM(I) AND ITS ANALOGS

Polyphenylacetylene, in good yields and with high molecular weight, ha s been obtained using three new Rh based catalytic systems, i.e. [Rh(C OD)(SC6F5)](2), [Rh(COD)(SC6H5)](2) and Rh(SC6F5)(P phi(3))(COD) where COD = 1,5-cyclooctadiene. H-1- and C-13-NMR spectra have shown that t he polyphenylacetylene obtained is highly stereoregular. The dependenc e of polyphenylacetylene yield and molecular weight on different exper imental factors, namely solvent characteristics and monomer initial co ncentration, is also discussed in this work. Although the mechanism by which these catalysts polymerize phenylacetylene has not been complet ely elucidated due to its high complexity, new information was obtaine d and a catalytic mechanism has been proposed.