Uncovering Structure-Activity Relationships in Sustainable Polymerisation Catalysis

Uncovering structure-activity relationships in homogenous polymerisation catalysis is essential in informing a rational approach to improve catalyst performance. This talk presents generalisable structure-activity relationships for a series of Co(III)M(I/II) heterodinuclear catalysts, where M(I/II) = Na(I), K(I), Ca(II), Sr(II), Ba(II), as applied to the ring-opening copolymerisation of epoxides and heterocumulenes (CO₂ or anhydrides).^{1, 2} These copolymerisation reactions enable the controlled, atom economical synthesis of polycarbonates and polyesters, both important polymers for a future circular materials economy.

Catalytic activity was found to correlate with M(I/II) Lewis acidity, peaking when M = K(I), and this finding proved to be general across different monomer combinations. These activity-acidity relationships provide insights into heterodinuclear synergy, as well as information on the distinct role of each metal in the polymerisation mechanism.

References:

(1) Butler, F.; Fiorentini, F.; Eisenhardt, K. H. S.; Williams, C. K. Structure-Activity Relationships for s-Block Metal/Co(III) Heterodinuclear Catalysts in Cyclohexene Oxide Ring-Opening Copolymerizations. Angew. Chem. Int. Ed. 2025, e202422497.

(2) Fiorentini, F.; Diment, W. T.; Deacy, A. C.; Kerr, R. W. F.; Faulkner, S.; Williams, C. K. Understanding catalytic synergy in dinuclear polymerization catalysts for sustainable polymers. Nat. Commun. 2023, 14 (1), 4783.

Biography:

image credit: Frederica Butler

Freya completed her MChem degree at the University of Oxford in 2023. Her master’s research, supervised by Prof. Charlotte Williams, focused on establishing structure-activity relationships in homogeneous polymerisation catalysis.¹

She is continuing research in this field during her PhD, under the supervision of Prof. Charlotte Williams and Prof. Michael Neidig, with a particular focus on iron-based heterodinuclear catalysts.