Visible colorimetric fluoride and hydroxide sensing by asymmetric tris-urea receptors: combined experimental and theoretical studies.

ABSTRACT: A series of asymmetric tris-urea receptors with electron withdrawing group (EWG) or electron donating group (EDG), L1-L4, were synthesized and characterized by high resolution mass spectroscopy (HRMS), nuclear magnetic resonance spectroscopy (NMR) and single-crystal X-ray diffraction (XRD) techniques. Receptors with EWG substituent showed different visible colorimetric response to fluoride and hydroxide anions. Binding studies toward various monovalent anions were performed by UV-Vis and NMR titration experiments. The experimental results revealed that these tris-urea receptors underwent stepwise deprotonation of the three N-H protons in the presence of varying excess of fluoride and hydroxide anions. This phenomenon was signalled by the development of vivid colours. These findings were al

SUBMITTER: Wang R 

PROVIDER: S-EPMC9090756 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature