An efficient ICT-based ratio/colorimetric tripodal azobenzene probe for the recognition/discrimination of F-, AcO- and H2PO4- anions.


Institute of Biomedical & Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 1068 Xueyuan Avenue, Shenzhen 518055, China. Electronic address: [Email]


The tripodal probe L was readily prepared via introducing rhodamine and azobenzene groups in a two-step procedure. Studies of the recognition properties indicated that probe L exhibited high sensitivity and selectivity towards F-, AcO- and H2PO4- through a ratiometric colorimetric response with low detection limits of the order of 10-7 M. The complexation behaviour was fully investigated by spectral titration, 1H NMR spectroscopic titration and mass spectrometry. Probe L not only recognizes F-, AcO- and H2PO4-, but can also distinguish between these three anions via the different ratiometric behaviour in their UV-vis spectra (387/505 nm for L-H2PO4-, 387/530 nm for L-AcO- and 387/575 nm for L-F- complex) or via different colour changes (light coral for L-H2PO4-, light pink for L-AcO- and violet for the L-F- complex). Additionally, given the presence of NH and OH groups in probe L, which can be protonated and deprotonated, probe L further exhibited an excellent pH response over a wide pH range (pH 3 to pH 12).


Anion,Ratio/colorimetric,Recognition/discrimination,Tripodal azobenzene probe,

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