Organometallic and chemical education research: An NMR investigation of the role of an aluminum alkyl during zirconocene catalyzed alkene polymerization and the development and evaluation of an online nanoscience course for teachers

AEI 35

Janice M. Hall Tomasik, janicehall@wisc.edu, Clark R. Landis, landis@chem.wisc.edu, and John W. Moore, jwmoore@chem.wisc.edu. Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706

NMR spectroscopy is used to directly monitor the behavior of an aluminum alkyl during the polymerization of 1-hexene by rac-(C2H4(1-indenyl)2Zr(Me)(MeB(C6F5)3).  The rates of polymerization are not inhibited by Al(iBu)2(BHT), Al(Me)(BHT)2, or Al(iBu)3 (BHT = 2,6-di-tert-butyl-4-methylphenyl).  Detailed measurement of polymerization rate and catalyst speciation demonstrate that BHT modified aluminum alkyls protect active sites from decomposition in the presence of protic impurities such as methanol.  Also presented is the design and evaluation of an online nanoscience course for teachers at the University of Wisconsin-Madison. The effectiveness of the course is evaluated using data from pre-surveys and formative and summative assessments of participants during the summer 2006 and spring 2007 semesters.