Recognition of Caffeine in Aqueous Solutions

Fiammengo, Roberto and Crego-Calama, Mercedes and Timmerman, Peter and Reinhoudt, David N. (2003) Recognition of Caffeine in Aqueous Solutions. Chemistry: a European journal, 9 (3). pp. 784-792. ISSN 0947-6539

PDF
Restricted to UT campus only: Request a copy
290Kb

Abstract:	Binding of caffeine in aqueous solutions has been achieved for the first time by using water-soluble, tetracationic peptide-porphyrin conjugates Zn-1 as the receptor molecules. The association constant for caffeine with receptor Zn-1 is in some cases as high as 6000 M-1, only 5-6 times lower than the highest binding constant reported for an artificial caffeine receptor in low polarity aprotic solvents. The binding mechanism has been studied by a combination of experimental techniques such as UV-visible and NMR spectroscopy and microcalorimetry. Recognition of caffeine involves both stacking with the porphyrin ring and metal coordination. Subtle variations of the receptor structure affect the complexation. Receptors Zn-1 have also been investigated for the recognition of molecules structurally related to caffeine, for example, 1-methylimidazole. Selectivity towards oxopurine derivatives (caffeine and theophylline) have been found.
Item Type:	Article
Copyright:	© 2003 Wiley InterScience
Research Group:	Supramolecular Chemistry and Technology (SMCT)
Link to this item:	http://purl.utwente.nl/publications/40871
Official URL:	http://dx.doi.org/10.1002/chem.200390088
Export this item as:	BibTeX EndNote HTML Citation Reference Manager

Repository Staff Only: item control page

Metis ID: 215563