METODI PER LO STUDIO DI PROCESSI DI RICONOSCIMENTO MOLECOLARE

The course aims to provide students with fundamental concepts and tools for the study of solution equilibria and the determination of complex species, stability constants and driving forces of molecular recognition processes in solution through common analytical techniques as well as methods and software for data analysis. Basic concepts on real-time monitoring of binding events occurring at the solid-liquid interface will be also presented.

Class lectures

Should teaching be carried out in mixed mode or remotely, it may be necessary to introduce changes with respect to previous statements, in line with the programme planned and outlined in the syllabus.

Molecular recognition: basic principles. Weak, non-covalent interactions. Hydrophobic effect. Complexation of charged and/or neutral species in solution. Receptors and supramolecular capsules for the recognition of cationic, anionic and neutral guests.

Host-guest complex equilibria. Multiple equilibria. Ligand competition. Role of ionic strength, solvent and pH on molecular recognition equilibria. Acid-base equilibria and species distribution. Conditional stability constant. pH control: choice of the most efficient buffering agents.

Determination of complex species and stability constants through analytical techniques (UV-vis, fluorescence, NMR, ITC). Titration design. Optimization of the experimental conditions. Errors in data collection. Binding isotherm. Graphical methods for the determination of both stoichiometry and binding constant of host-guest complexes. Main issues.

Data treatment. Non-linear least-square analysis. Major software. Analysis of titration data through spreadsheets.

Determination of the energetics of reaction and the driving forces of molecular recognition processes in solution. Direct measurement of the heat of a reaction vs. van’t Hoff method. Isothermal titration calorimetry (ITC). Determination of K and ΔH of a reaction through ITC titrations. Calorimetric data analysis, main models and software. Simultaneous analysis of different observables for the study of multiple equilibria in complex host-guest systems.

Basic concepts on molecular recognition at the solid-liquid interface. SPR and QCM-D techniques. Real-time monitoring of molecular interactions at the interface (binding constants and kinetics).

Capitoli selezionati dai seguenti libri di testo:

1. J. W Steed, J. L. Atwood, Supramolecular Chemistry, 2° ed., John Wiley & Sons, 2009

2. J. W. Steed, D. R. Turner, K. Wallace, Core Concepts in Supramolecular Chemistry and Nanochemistry, John Wiley & Sons, 2007

3. E. V. Anslyn, D. A. Dougherty, Modern Physical Organic Chemistry, University Science Books, 2005

4. J. L. Atwood, G. W. Gokel, L. Barbour editors, Comprehensive Supramolecular Chemistry II, 2 ed., Vol. 2: Experimental and computational methods in supramolecular chemistry, Elsevier, 2017

5. J. W Steed, P. A. Gale editors, Supramolecular Chemistry: From Molecules to Nanomaterials, Vol. 1-3, John Wiley & Sons, 2012

6. D. C. Harris, Chimica Analitica Quantitativa, terza ed., Zanichelli, Bologna, 2017

7. D. A. Skoog, D. M. West, F. J. Holler, S. R. Crouch, Fondamenti di Chimica Analitica, 3° ed., Edises, 2015