A reaction-based near-infrared (NIR) fluorescent probe, (E)-4-(2-(4-(dicyanometh- ylene)-4H-chromen-2-yl) vinyl)phenyl picolinate (DCM-P), was designed and synthesized by employing the dicyanomethylene-4H-pyran chromophore as the fluorophore and the 2-picolinic ester group as the recognition unit. The proposed probe DCM-P showed significant NIR fluorescence "turn-on" response to Cu2+ with distinct colorimetric change from yellow to purple. The recognition mechanism of probe for Cu2+ was confirmed by fluorescence spectroscopy, H-1 NMR spectra, HAMS spectrometry and TD-DFT calculations. The prob...
