Diffusion NMR of Self-Assembled Molecular Capsule and Beyond

Yoram Cohen, School of Chemistry, Tel Aviv, Tel Aviv, Israel

Self-assembled molecular capsules, host-guest systems and supramolecular polymers have attracted considerable interest in recent years because of their possible application in different fields. However, the determination of their detailed structures and their host-guest interactions in solution may be sometime difficult to obtain. In the present lecture we will demonstrate, through the use of selected examples, how diffusion NMR (1) can assists in determining the supramolecular structures of such systems in solution. Examples of self-assembled molecular capsules (2), host-guest systems (3) and self-assembled polymers (4) will be presented. The structure, the self-sorting, the interaction with guests and the fate of encapsulated solvent molecules in such hexameric capsules will be reported. The formation of a tertiary complexes of xenon with a water soluble pillar[5]arene and the formation of supramolecular polymers will be presented. If time permits the potential of angular double pulsed field gradient (d-PFG) NMR experiments in characterizing emulsion will be presented (5).

1) Y. Cohen, L. Avram, L. Frish, Angew. Chem. Int. Ed., 44, 520-554 (2005); 2) L. Avram, Y. Cohen, J. Am. Chem. Soc., 126, 11556-11563 (2004); S. Slovak, L. Avram, Y. Cohen, Angew. Chem. Int. Ed., 49, 428-431 (2010); V. Guralnik, L. Avram, Y. Cohen, Org. Letters, 21, 5592-5595 (2014). 3) T. Adiri, D. Marciano, Y. Cohen, Chem. Comm., 63, 7082-7804 (2013). 4) S. Pappalardo, V. Villari, S. Slovak, et al., Chem. Eur. J., 29, 8164-8173 (2007); C. Capici, Y. Cohen, A. D'Urso, et al., Angew. Chem. Int. Ed., 50, 11956-11961 (2011). 5) N. Shemesh, Y. Cohen, J. Am. Chem. Soc., 133, 6028-6035 (2011).