No abstract

When supported upon dehydroxylated (DA) or partially dehydroxylated (PDA) alumina, the organozirconium complexes (C5H6)2Zr(CH3)2 (1), [(CH3)5C5]2Zr(CH3)2 (2), and [(CH3)5C5]Zr(CH3)3 (3) are highly active catalysts for propylene hydrogenation. Turnover frequencies (s-1) at -63 °C (DA, PDA) are as follows:for 1, 0.3, 0.1; for 2, 0.2, 0.06; and for 3, 1.1, 0.3. CO poisoning experiments indicate 54% of 1/DA and 512% of 3/DA Zr sites are catalytically active. Ethylene polymerization activity follows the order 3 » 1=2, and DA > PDA. Solid-state 13C CPMAS NMR spectra of (C6H5)2Zr(*CH3)2/DA and (C5H5)2Zr-(*CH3)2/PDA (*C = 90% 13C) evidence *CH3 transfer to A1 surface sites and formation, inter alia, of Cp2Zr(*CH3)+ species. Such processes also occur on PDA.

No abstract

No abstract

No abstract

No abstract

No abstract

No abstract