Polymerization of α-olefins with pyridylamidohafnium catalysts: Living behavior and unexpected isoselectivity from a Cs-symmetric catalyst precursor

INOR 277

Gregory J. Domski, gjd9@cornell.edu, Emil Lobkovsky, and Geoffrey W. Coates, gc39@cornell.edu. Department of Chemistry and Chemical Biology, Cornell University, Baker Laboratory, Ithaca, NY 14853-1301
Pyridylamidohafnium catalysts bearing a methylene bridge linking the pyridine and amido moieties were prepared and employed for 1-hexene and propylene polymerization. Polymerizations of 1-hexene by 1/B(C6F5)3 in a living fashion furnished poly(1-hexene)s with narrow polydispersities (PDIs) (Mw/Mn ≤ 1.20) and exhibited a linear increase in number average molecular weight (Mn) with increasing monomer conversion. The poly(1-hexene)s and polypropylene (PP) produced by 1/B(C6F5)3 were unexpectedly isoenriched ([m4] = 56 % for PP); statistical analysis at the pentad level of the PP sample indicated that the observed isoselectivity was a result of enantiomorphic site control.

 

Organometallic Catalysts
7:00 PM-10:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Inorganic Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007