Investigations into Asymmetric Post-Metallocene Group 4 Complexes for the Synthesis of Highly Regioirregular Polypropylene
Abstract
A series of asymmetric post-metallocene group 4 complexes based on a modular anilide(pyridine)phenoxide framework have been synthesized and tested for propylene polymerization activity. These complexes, upon activation with methylaluminoxane (MAO), produce highly regioirregular and stereoirregular polypropylene with moderate to good activities. Surprisingly, modification of the anilide R-group substituent from 1-phenethyl to benzyl or adamantyl did not significantly change the polymer microstructure as determined by ^(13)C NMR spectroscopy. Although polymer molecular weights and polydispersities vary with propylene pressure, temperature, and activator, regio- and stereoirregularity were also found to be relatively insensitive to these variables. When the polymerization is conducted at 70 °C under dihydrogen, partial decomposition to a highly active catalyst that produces an isotactic microstructure occurs; the undecomposed catalyst continues to produce highly regioirregular and stereoirregular polypropylene under these conditions.
Additional Information
© 2014 American Chemical Society. Received: February 28, 2014; Revised: April 28, 2014; Published: May 14, 2014. The authors gratefully acknowledge the USDOE Office of Basic Energy Sciences (DE-FG03-85ER13431 to J.E.B.) for funding. An NSF-GRF to R.C.K. is gratefully acknowledged. We thank Larry Henling, Dr. Michael Takase, and Dr. Wojciech Bury for assistance with X-ray crystallography.Attached Files
Supplemental Material - ma500453t_si_001.pdf
Supplemental Material - ma500453t_si_002.cif
Supplemental Material - ma500453t_si_003.cif
Supplemental Material - ma500453t_si_004.cif
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Additional details
- Eprint ID
- 46591
- DOI
- 10.1021/ma500453t
- Resolver ID
- CaltechAUTHORS:20140701-092911451
- Department of Energy (DOE)
- DE-FG03-85ER13431
- Created
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2014-07-01Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field