Gustavo Lopes Camelo

Topic

Building Complexity from the Bottom-Up: Fundamental Studies of Emergence in Supramolecular Systems Using Cucurbit[n]uril Host-Guest Chemistry

Department of Chemistry

Date & location

• Friday, September 5, 2025
• 9:30 A.M.
• Elliott Building, Room 305

Examining Committee

Supervisory Committee

• Dr. Cornelia Bohne, Department of Chemistry, University of Victoria (Supervisor)
• Dr. Fraser Hof, Department of Chemistry, UVic (Member)
• Dr. Kim Venn, Department of Physics and Astronomy, UVic (Outside Member)

External Examiner

• Dr. Joseph Moran, Department of Chemistry and Biomolecular Sciences, University of Ottawa

Chair of Oral Examination

• Dr. Kathy Sanford, Department of Curriculum and Instruction, UVic

Abstract

Supramolecular chemistry has traditionally been concerned with the measurement of pairwise interactions. Systems chemistry has more recently introduced the concept of emergence in mixtures of components that display system-level properties. Research on systems chemistry is intimately linked with life, from the study of its origin to drawing inspiration to research new functional materials. Supramolecular and systems chemistry converge in the study of dynamic, reversible systems, which are fundamental to the emergence and maintenance of life. In this doctoral dissertation, I studied two system-level milestones to achieve life-like properties from the interplay of fundamental building blocks: diversity and out-of-equilibrium systems. More specifically, I focussed on how these properties emerge from the fundamental supramolecular interactions and can be intentionally conceived.

Chapter 2 introduces a methodology to study supramolecular complexity that was applied to revisit a host-guest system. A chemistry-informed speciation table was generated for a system composed of cucurbit[7]uril (CB[7]), a cationic organic guest, and sodium cations. To interrogate the system, key competitors with special properties were introduced, leading to the characterization of specific complexes. The method led to the discovery of a new emerging property based on excimer emission, and also to a broader understanding of the dynamics of the formation of metal cation-capped host-guest complexes and the formation of exclusion complexes that influence the dissociation dynamics. In Chapter 3, this method was extended to a family of naphthylamines in their interactions with CB[7] to study properties and the mechanism of complex dissociation. The chapter explored the structure-dynamics relationship between host and guest: the presence of a hydrophobic envelope on the positive charges of the guests as well as the position of the ammonium group led to additive effects.

Finally, in Chapter 4, I designed a kinetically host-guest system that can be kept out of equilibrium. The methodology was based on kinetic simulations of the interactions of a ditopic guest, N-(1-naphthyl)-pentane-1,5-diammonium cation (ANA) to CB[6] and CB[7] and was put to test in proof-of-concept experiments. Although the kinetic effect was observed, I envisioned the incorporation of a supramolecular diversity-based approach to improve the experiment-simulation fidelity of the system and I propose how to transfer the same design philosophy into the development of a dissipative system.