Abstract
Cp(2)Hf(CH(3))(2) reacts with silica containing strong aluminum Lewis sites to form Cp(2)Hf-(13)CH(3)(+) paired with aluminate anions. Solid-state NMR studies show that this reaction also forms neutral organohafnium and hafnium sites lacking methyl groups. Cp(2)Hf-(13)CH(3)(+) reacts with isotatic polypropylene (iPP, M(n) = 13.3 kDa; Đ = 2.4; mmmm = 94%; ∼110 C(3)H(6)/Hf) and H(2) to form oils with moderate molecular weights (M(n) = 290-1200 Da) in good yields. The aliphatic oils show characteristic (13)C{(1)H} NMR properties consistent with complete loss of diastereoselectivity and formation of regioirregular errors under 1 atm H(2). These results show that a Ziegler-Natta-type active site is compatible in a common reaction used to digest waste plastic into smaller aliphatic fragments.