Synthesis And Properties’ Investigation Of Fluorescent Benzylidenecyclohexanone Derivatives

In this paper, a series of fluorescent Benzylidenecyclohexanone derivatives have been successfully synthesized by Staudinger, Click reaction. Meanwhile, its performance of optical, ion recognition and electrochemical were systematically studied. And it is found that the materials can be used as fluorescent sensors. The specific research results are as follows:1. A type of fluorescent benzylidenecyclohexanone-containing phosphinimine derivative M1 has been synthesized via catlyst-free Staudinger reaction. The fluorescence and ion recognition properties of M1 have been studied, finding that M1 has a specific selectivity of H+. Yellow fluorescence of M1 solution is fading when H+ existing. This phenomenon indicates that M1 has the ability to be a turn-off mode sensor for H+(LOD = ~2.31×10-7 M). Continue to add F- of halogens in the system, according to the strong interaction between H+ and F-, the fluorescence recover to the initial. This suggests that protonated M1 has the ability to distinguish F- from other halogens, with optical turn-on mode.2. On the preliminary study of M1, benzylidene cyclohexanone structure has been proved to be a kind of good conjugated bridge. On this basis, we have successfully synthesized a conjugated polymer P5 containing benzylidene cyclohexanone in the main chain structures. Its optical properties, ion recognition properties have been further studied. When I- was added into P5 solution, the blue fluorescence of the solution was quenching significantly. In the interference experiment, it is found that P5 has a specific recognition of I-(LOD = ~3.36×10-7 M). To continue to add Hg2+ into the P5-I- system, the fluorescence intensity recover to initial, and the other cations has little effect on P5-I- system(LOD = ~4.47×10-8 M).3. P5 has been further modified by triphenylphosphine(TPP) via Staudinger reaction, getting phosphinimine-end conjugated polymer P5-TPP. Through the study of optical properties, the recognition abilities, finding that P5-TPP can specifically recognize ClO- in common oxides(LOD = ~2.37×10-7 M). And prominent fluorescence ratiometric change has been observed. The recognition mechanism has been carried out through ESI-MS, 1HNMR, IR and other characterization methods.