Non-π-Allyl Mechanism for the 1,4-cis-Butadiene Polymerization: Theoretical Study of Polymerization via Insertion of Butadiene into Al-C Bond with Cationic Gadolinium Metallocene.

This paper reports a computational study on the specific 1,4-cis polymerization of butadiene catalyzed by the cationic gadolinium metallocene [(C Me ) Gd][B(C F ) ] combined with excess amount of Al( Bu) . Because this reaction system has no initial Gd-alkyl bond, a mechanism with conventional coordinative chain transfer polymerization (CCTP) is not feasible. Density functional theory (DFT) analyses indicate a novel mechanism in which the cationic Gd plays a crucial role by assisting butadiene insertion into one of the Al-C bond of Al( Bu) .

Polymerization via Insertion of Ethylene into Al-C bond under Mild Conditions: Mechanistic Studies on the Promotion Exerted by a Catalytic Amount of Cationic Gadolinium Metallocene.

The cationic gadolinium metallocene [(C Me ) Gd][B(C F ) ], when combined with an excess amount of Al( Bu) , efficiently produces polyethylene at 80 °C under 0.8 MPa pressure of ethylene. After quenching, the resulting polyethylene has ethyl group at one end and isobutyl group at the other terminal.

Generation of cationic indenyl silylamide gadolinium and scandium complexes [(Ind)Ln{N(SiMe3)2}]+[B(C6F5)4]- and their reactivity for 1,3-butadiene polymerization.

Highly efficient cis-polymerization of butadiene was achieved by using new bis(indenyl) silylamide rare earth complexes with the cooperation of both a borate salt and i-Bu3Al; treatment of these complexes with organoboron compounds unexpectedly yielded new cationic mono(indenyl) amido species relevant to polymerization.