Molecular recognition and fluorescent sensing of urethane in water

Molecular recognition and fluorescent sensing of Group 2A carcinogen-urethane was achieved in aqueous solution. The molecular sensors are the endo-functionalized molecular tubes with amide protons in the hydrophobic cavity. H-1 NMR, fluorescence, and ITC titrations and single crystal X-ray crystallography reveal the binding stoichiometry, the binding affinities, and the driving forces. The binding is mainly driven by the hydrophobic effect through releasing the high-energy cavity water with minor contribution from hydrogen bonding. In addition, the syn-configured molecular tube was found to be a good fluorescent sensor for urethane in water (concentration range: 6.2-60 mu mol/L) and in beer (concentration range: 22.9-60 mu mol/L). (C) 2018 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.