Unlike different types of Lewis pairs as polymerization catalysts for acrylic monomers, we herein report on organometallic aluminum(III) compounds with adapted Lewis acidity, which show a surprisingly high polymerization activity without any further initiator. Due to the variable ligand structure of these single-site aluminum organyls, this work provides a new family of environmentally benign main group element catalysts affording high-molecular weight products with surprisingly narrow dispersities. DFT calculations, end group analysis and kinetic investigations clearly suggest a main group element (MGE) group transfer polymerization (GTP) mechanism analogous to the known metal-mediated GTP mechanism. The broad applicability of this MGE-GTP is evidenced by the exemplary use of sterically and electronically diverse <i>Michael</i>-type monomers. Even the controlled polymerization of the highly reactive acrylonitrile can be achieved in a decent manner. Additionally, extended <i>Michael</i>-type structures like 4-vinyl pyridine are accessible. Especially Al(III)-half metallocenes show an almost quantitative initiator efficiency and, combined with the living character of the polymerization reactions, they enable the facile preparation of polymer block architectures, actually of unconventional monomer combinations.

All for aluminum: Single-component, main group element mediated group transfer polymerization

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.