The initiation of polymerization by organometallic compounds—V. The termination mechanism in the polymerization of acrylonitrile initiated by tetrakis(dimethylamido)titanium(IV)

A simple method is described for the preparation of pure, dry alcohols, tritiated in the hydroxyl group. The polymerization of acrylonitrile initiated by tetrakis(dimethylamido)titanium(IV) has been terminated by quenching with tritiated isopropanol at varying reaction times, and the radioactivity of the polymer has been determined, in order to measure the concentration of metal-polymer bonds present in the reaction. The results indicate that about 97 per cent of the polymer present has been terminated by a reaction leading to detachment of the polymer chain from the metal centre. A very small fraction of the total polymer is terminated by a reaction which does not lead to detachment of the polymer. Possible reaction mechanisms are discussed.