Oral Presentation Royal Australian Chemical Institute National Congress 2026

Molecular Confinement Effects on Pressure-Driven Structural Evolution of C60 (136602)

Chengyi Liu 1 , Xingshuo Huang 2 , Shuailing Ma 3 , Aditya Rawal 4 , Mohammad Tajiki 5 , William Alexander Donald 5 , Colin L Raston 6 , Dong Jun Kim 5 , Jodie E Bradby 2 , Sam Chen 1
  1. Discipline of Chemistry, School of Science, University of Newcastle, Callaghan, NSW, Australia
  2. Research School of Physics, The Australian National University, Canberra, ACT, Australia
  3. Institute of High Pressure Physics, School of Physical Scientific and Technology, Ningbo University, Ningbo, Zhejiang, China
  4. Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW, Australia
  5. School of Chemistry, Univeristy of New South Wales, Sydney, NSW, Australia
  6. Flinders Institute for Nanoscale Science and Technology, College of Science and Engineering, Flinders University, Adelaide, SA, Australia

High pressure can induce irreversible phase transformations in bulk C60, yet the detailed pathways of phase evolution and strategies to control these processes under extreme conditions remain largely unclear. Here, we investigate the structural transformations of C60 and its supramolecular complex with p-But-calix[8]arene (C60/calix[8]arene) at room temperature under high pressure using a diamond anvil cell (1–20 GPa) and a cubic multi-anvil press (1–15 GPa). Microscopic and spectroscopic characterizations revealed that compression of C60 to 5 GPa yielded a heterogeneous mixture of monomers, dimers, and sp2-rich amorphous phases. Sequential solvent extractions and analyses support a mechanism in which densification and grain refinement promote dimerization along grain boundaries while trapping monomers within crosslinked networks. In contrast, C60 encapsulated within calix[8]arene exhibited fully reversible structural changes under similar conditions, with the layered architecture of the complex providing spatial confinement that prevents pressure-induced polymerization. These findings demonstrate that molecular confinement can suppress fullerene crosslinking under extreme conditions, offering a strategy to tailor the structure and properties of C60-based materials.