Oral Presentation Royal Australian Chemical Institute National Congress 2026

Surprising new heteroatom binding motifs of porphyrins and related tetradentate macrocycles (137014)

Maxwell J Crossley 1 , Peter J Canfield 1
  1. The University of Sydney, The University Of Sydney, NSW, Australia

Porphyrins and related tetradentate macrocycles exhibit a rich diversity of chelating modes that underpin their central roles in catalysis, photophysics, and bioinorganic chemistry. Despite decades of study, the systematic organisation of all possible binding motifs and their interconversion pathways remains incomplete. This talk presents the application of the Polytope Formalism as a mathematically rigorous framework for exhaustively generating and organising all atom-connectivity configurations relevant to macrocyclic binding. By treating ligation as a discrete configuration space and encoding interconversions as reaction graphs, the formalism enumerates both stable binding modes and mechanistically relevant intermediates. The resulting configuration spaces reveal structured topologies that map directly onto associated potential-energy surfaces, providing new insight into known motifs and highlighting unexplored regions of chemical possibility. This approach establishes a general, scalable methodology for analysing macrocyclic coordination chemistry and for systematically navigating the binding landscapes of complex ligands.

  1. P. J. Canfield and M. J. Crossley, The Polytope Formalism: application to molecular constitution and the prospect of a complete description of Chemical Space, Chem. Sci., 2026, 17, 2102-2118, DOI: 10.1039/d5sc08813e.
  2. P. J. Canfield and M. J. Crossley, Rigorous treatment of polytopal rearrangements reveal surprising complexity of stereoisomerism configuration landscapes, Chem. Sci., 2025, 16, 6705-6719, DOI: 10.1039/d4sc08628g