A Fluorescent Organic Probe for Naked‐Eye Detection of Chloromethanes

Abstract

An organic fluorescent probe (OFP‐TAR) with a propeller‐like structure was designed and synthesized. The photoluminescence of OFP‐TAR in solution exhibited a significant red shift with the increase of solvent polarity, enabling a transition of fluorescence emission from blue (445 nm) to yellow (540 nm). The organic thin‐film materials based on OFP‐TAR/PMMA exhibit significant color changes upon exposure to CH2Cl2, CHCl3, and CCl4, with their maximum fluorescence wavelengths measured at 445, 471, and 494 nm respectively. The device facilitates the visual detection of chloromethanes and is capable of enduring more than 7 cycles of testing. These materials can also be prepared as binary‐coded microarray data storage devices or applied in the field of anti‐counterfeiting. The quantum yields of guest‐loaded crystals CH2Cl2@OFP‐TAR, CHCl3@OFP‐TAR and CCl4@OFP‐TAR are observed as 19.13%, 8.79%, and 0.83% respectively, which are consistent with the tendency of OFP‐TAR in CH2Cl2 (47.30%), CHCl3 (34.27%) and CCl4 (3.10%). The fluorescence properties of OFP‐TAR, OFP‐TAR/PMMA, guest‐loaded and guest‐free crystals provided insights into the special response mechanism of OFP‐TAR towards different chloromethanes.