In the broad area of supramolecular chemistry, an essential member of the host family, cucurbit[n]uril (CB[n], n = 5, 6, 7, 8, 10), has attracted much attention because of its ability to form ultra-stable complexes with various guests.1 The two primary distinctive features of CB[n] hosts are their (i) rigidity and (ii) circularly symmetrical structure.2 These two features define a roughly spherical internal cavity, and the carbonyl-lined portals would provide restricted access to those cavities. The strong hydrophobic effect between the host cavity and guests, ion-dipole and dipole-dipole interactions of guests with CB portals help in cooperative and multiple non-covalent interactions essential for realizing such strong complexations. Numerous spectroscopic, spectrometric, electrochemical, thermal, and crystallographic techniques are generally used to study the supramolecular interaction between the host and guest molecules. Discovering record binding affinities of guest molecules in CB’s hydrophobic cavity using any analytical technique gives a numerical understanding of binding affinity.3 This understanding may lead to various applications, such as sensing and drug delivery. Herewith, we will present how to estimate the binding constant values from titration or competitive experiments using various spectroscopic tools.4
References :
1. Mukhopadhyay, R.D., Kim, K. Nat. Chem. 2023, 15, 438.
2. Murray, J. Kim, K. Ogoshi, T. Yaod W. Gib, B. C.; Chem. Soc. Rev., 2017, 46, 2479.
3. Barrow, S. J., Kasera, S., Rowland, M. J., Barrio, J., Scherman, O. A.; Chem. Rev. 2015, 115, 12320−12406.
4. Thordarson P.; Chem. Soc. Rev., 2011, 40, 1305–1323.