| COMPLEXATION of CINNAMIC ACID by CUCURBIT[7]URIL for ENHANCING PHOTOISOMERISATION CONVERSION Na'il Saleh1; 1UNITED ARAB EMIRATES UNIVERSITY, Al-Ain, United Arab Emirates; PAPER: 23/SolutionChemistry/Regular (Oral) SCHEDULED: 16:45/Wed. 30 Nov. 2022/Game ABSTRACT: The paper presents the supramolecular control of photoisomerization reactions of cinnamic acid (CA), belonging to the class of α,β-unsaturated carbonyl compounds, utilizing the rigid cavity of cucurbit[7]uril (CB7). Irradiation by UV light (300 and 254 nm) of an aqueous solution of the complex induces the E-to-Z-conformational change, as evidenced by UV-visible absorption spectroscopic and 1H-NMR techniques. CA and CB7 form a stable 1:1 host–guest complex with moderate binding constant (K = 3.3 x 103 M-1). The photo-switchable “on-off” host–guest system shows a higher reversibility and switching efficiency, when compared to the unbound molecules, which makes it potentially useful in designing photoresponsive gating systems. The results presented herein highlight the value of a supramolecular approach in achieving selectivity in photoreactions and opening reaction pathways that are latent in solution chemistry. References: REFERENCES: [1] A. G. Mejuto, J. Morales, J. Rial-Otero, R., S. J. Gándara (2010). Factors controlling flavors binding constants to cyclodextrins and their applications in foods. Food Res. Int., 43 ( 2010) 1212-1218. |
