Ring-Opening Metathesis Polymerization of Norbornene by Cp*2Os2Br4 and Related Compounds
نویسندگان
چکیده
The dinuclear complex Cp*2Os2Br4 (Cp* ) pentamethylcyclopentadienyl) and related mono(pentamethylcyclopentadienyl)osmium compounds are catalysts for the ring-opening metathesis polymerization (ROMP) of norbornene. The most active catalyst prepared to date is made by treatment of Cp*2Os2Br4 with methylaluminoxane. This catalyst polymerizes norbornene with yields up to 167 kg of polymer per mol of catalyst at room temperature. The 13C NMR spectra show that the polymer is slightly blocky and that cis double bonds predominate. The polymer is insoluble in organic solvents but is swelled by many of them.
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