H 2 ‐D 2 exchange reaction with MgCl 2 ‐supported Ziegler catalyst by stopped‐flow method

The effect of hydrogen on the chain transfer reaction in the initial stage of propene polymerization with MgCl 2 ‐supported Ziegler catalyst was studied through H 2 ‐D 2 exchange reaction using the stopped‐flow method. When the exchange reaction was carried out with various catalyst components at room temperature for 5 min, HD was produced only in case of using the catalyst with Al(C 2 H 5 ) 3 . In case of the stopped‐flow method (reaction time ca. 0.1 s), the catalyst without pre‐treatment with Al(C 2 H 5 ) 3 showed no activity for the H 2 ‐D 2 exchange reaction (no HD produced), while the catalyst with pre‐treatment had exchange activity. As the chain transfer activity of H 2 in propene polymerization shows the same tendency, it is evident that chain transfer with H 2 occurs via atomic hydrogen generated on the pre‐treated catalyst.