Synthesis And Fluorescent Spectra Research Of Naphthalimide Derivatives (Ⅱ)

As the metal ions and hydrogen ions in the life course have an important role, and fluorescence detection has many advantages, so people design fluorescent chemical sensors to detect the presence of these substances. First, a series of fluorescent probes in recent years were introduced on the basis of different fluorescent probes which can recognize different ions. Secondly, though 4-Br-1,8-naphthalic as the Precursor compounds, the piperdine, morpholine, pyrrolidine and dimethylamine are be replaceed on the four, as well as Diethylenetriamine or derivatives of ethanolamine are reacted with anhydride , a dozen of novel fluorescent probes with different receptors were designed and synthesized based on the 4-amino-1, 8-naphthalimid. And these compounds′structure are correct by spectral analysis. The UV-Visible and fluorescent properties of these 1,8-naphthalimide derivatives in various solution or under various pH or the selective to ions were investigated.The results showed that compounds 5a-5d in cyclohexane, compounds 6a-6d in dichloromethane, compounds 7a-7d in cyclohexane have the highest fluorescence quantum yield; compounds 5a-5d, compounds 6b-6d and compounds 7a -7d in pure aqueous solution can not occur the chang of fluorescence intensity with changes of pH. It was found that one compound (6a) exhibited strong fluorescent pH-sensing. Its fluorescence intensity increase with increasing pH value and the figure of fluorescence intensity and different pH value is linear. However, this paper does not achieve the desired result, no fluorescent chemosensor to metal ions be obtained. And we can modified the structure of the 7a-7d series from ester to amide bond, maybe its ability to identify metal ions that may be satisfied with the results.