Oral Presentation Royal Australian Chemical Institute National Congress 2026

Protons as radical initiators (136845)

Asja A. Kroeger 1 , Maria-Nefeli Antonopoulou 2 , Glen R. Jones 2 , Zhipeng Pei 1 , Nghia P. Truong 2 3 , Timon Egger 2 , Athina Anastasaki 2 , Michelle L. Coote 1
  1. Institute for Nanoscale Science and Technology, College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
  2. Laboratory of Polymeric Materials, Department of Materials, ETH Zürich, Zürich, Switzerland
  3. Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia

Most molecular species are polar or at least polarizable, meaning that strategically aligned electric fields could be employed to catalyze their reactions. In 2016, the Coote group and collaborators provided the first experimental demonstration of this by using Scanning Tunnelling Microscopy (STM) to orient reactants in an electric field and catalyze prototypical Diels Alder reactions.[1] While this provided a proof-of-principle, this approach is not easily scalable in chemical synthesis. In enzymes, charged residues serve to create large internal fields that bind substrates in a controlled manner that optimizes catalysis.[2] Translating this to small-molecule-catalysis, the Coote group showed that incorporation of charged functional groups directly on the substrates can deliver localized oriented electric fields, meaning that electrostatic catalysis could be modulated simply through pH changes.[3] Here, we show computationally and experimentally that abundant acids can be employed to create charged functional groups on a wide range of vinyl monomers, stabilizing both their initiation and propagation transition structures in their radical polymerizations.[4] We demonstrate that this not only makes typically explosive traditional initiators redundant but also provides access to cleaner polymerization reactions by avoiding initiator-driven side-reactions. Using the different polarizabilities of excited states, we show that the scope of this acid catalysis expands to photo polymerization.[5]

 

  1. A. C. Aragonès, N. L. Haworth, N. Darwish, S. Ciampi, E. J. Mannix, G. G. Wallace, I. Diez-Perez and M. L. Coote, Nature 2016, 531, 88-91.
  2. a) S. D. Fried, S. Bagchi and S. G. Boxer, Science 2014, 346, 1510-1514; b) A. Warshel, P. K. Sharma, M. Kato, Y. Xiang, H. Liu and M. H. M. Olsson, Chemical Reviews 2006, 106, 3210-3235.
  3. a) G. Gryn'ova, D. L. Marshall, S. J. Blanksby and M. L. Coote, Nature Chemistry 2013, 5, 474-481; b) G. Gryn’ova and M. L. Coote, Journal of the American Chemical Society 2013, 135, 15392-15403; c) M. Klinska, L. M. Smith, G. Gryn'ova, M. G. Banwell and M. L. Coote, Chemical Science 2015, 6, 5623-5627.
  4. M.-N. Antonopoulou, G. R. Jones, A. A. Kroeger, Z. Pei, M. L. Coote, N. P. Truong and A. Anastasaki, Nature Synthesis 2024, 3, 347-356.
  5. M.-N. Antonopoulou, N. P. Truong, T. Egger, A. A. Kroeger, M. L. Coote and A. Anastasaki, Angewandte Chemie International Edition 2025, 64, e202420733.