Molecular Structure of 113C‐C2H4/C3H6 Copolymers Prepared in the Presence of Half Sandwich Titanium Methyl – B(C6F5)3 Catalysts

Abstract

Listen

Translate article

AbstractSummary: Copolymers of propylene with 113C‐ethylene (99% isotopic purity) have been prepared in the presence of Cp*Ti(CH3)3 – B(C6F5)3 (I) or CpTi(CH3)3 – B(C6F5)3 (II) (Cp = cyclopentadienyl, Cp* = pentamethylcyclopentadienyl). 13C NMR analysis confirms previous findings that propylene polymerization in the presence of I is highly regioselective and somewhat isoselective, while catalyst II produces regioblock polypropylene. In the presence of II, polymerization is slightly syndioselective and the average size of the primary regioblocks seems larger than that of the secondary ones. Moreover, secondary insertion seems more syndioselective than the primary.13C NMR spectra of samples I.2 and II.2.magnified image13C NMR spectra of samples I.2 and II.2.