Folding, wrapping and clipping: stories of host-guest and self-inclusion complexes

Anion binding with supramolecular receptors aims to provide selective sensors and extracting agents for various analytes.[1] Important milestones are to understand how adding binding functionalities to a single receptor affects the complexation properties, as well as, how the stability of host-guest complexes changes in different solvents. We have investigated acyclic and macrocyclic supramolecular receptors with the aim to understand which structural modifications improve the binding affinity towards targeted guest and how we can control the folding and self-assembly of supramolecular hosts with anions. The results are based on X-ray structures, NMR spectroscopy, isothermal titration calorimetry, and density functional theory calculations. Case studies introducing several types of supramolecular hosts including aryl amide foldamers,[2] resorcinarenes,[3] and calix[4]pyrroles are presented.[4]

References

[1] L. Chen, S.N. Berry, X. Wu, E.N.W. Howe, P.A. Gale, Chem. 6 (2020) 61–141; Q. Zhang, Y. Zhou, M. Ahmed, N.M. Khashab, W. Han, H. Wang, Z.A. Page, J.L. Sessler, J. Mater. Chem. A. 10 (2022) 15297–15308.

[2] K. Helttunen, R. Annala, A. Suhonen, J. Iloniemi, E. Kalenius, G. Aragay, P. Ballester, H.M. Tuononen, M. Nissinen, Chem. Asian J. 14 (2019) 647–654.

[3] M. Pamuła, M. Nissinen, K. Helttunen, Chem. Eur. J. 26 (2020) 7374–7383.

[4] M. Pamuła, E. Bulatov, K. Helttunen, manuscript submitted (2022); K. Helttunen, Eur. J. Org. Chem. (2022), just accepted, DOI: 10.1002/ejoc.202200647