A Supported Ziegler-Type Organohafnium Site Metabolizes Polypropylene.

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.