[(RR′-admpzp)2Ti(OPri)2] complexes (2a-c), synthesized from reaction of Ti(OPri)3Cl (0.5 equiv) with 1-dialkylamino-3-(3,5-dimethyl-pyrazol-1-yl)-propan-2-ol compounds in the presence of triethylamine (0.5 equiv), are pseudo-octahedral with each RR′-admpzp ligand κ2-O,N(pyrazolyl) coordinated to the titanium center. In solution, 2a-c adopt isomeric structures that are in dynamic equilibrium. At 23 °C, 2a-c/1000 MAO catalyst systems furnished high molecular weight polymers with narrow molecular weight distributions (Mw/Mn = 2.7-2.8). At 100 °C, 2a-c/MAO catalyst systems exhibited increased polymerization activity and 2c/1000 MAO system furnished high molecular weight polyethylene with a molecular weight distribution (Mw/Mn = 2.1) that is close to that found for single-site catalysts.
|Number of pages||8|
|Journal||Journal of Organometallic Chemistry|
|State||Published - Nov 15 2007|
Bibliographical noteFunding Information:
Thanks are expressed to the US National Science Foundation (Grant No. CHE-0416098) for financial support of this work. NMR instruments utilized in this research were funded in part by the CRIF program of the US National Science Foundation (Grant No. CHE-9974810). This work made use of the materials characterization facility of the Cornell Center for Materials Research (CCMR) with support from the National Science Foundation Materials Research Science and Engineering Centers (MRSEC) Program (DMR 0520404).
- 1-Dialkylamino-3-(3,5-dimethyl-pyrazol-1-yl)-propan-2-olate ligands
- Olefin polymerization
- Titanium(IV) catalysts
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
- Materials Chemistry