4-[2-(二甲氨基)乙氧基]-N-十八烷基-1,8-萘酰亚胺荧光染料的合成及其性能研究

以4-溴-1,8-萘酐为原料,合成脂溶性4-2-(二甲氨基)乙氧基]-N-十八烷基-1,8-萘酰亚胺。对其进行了1H NMR和IR表征。考察了荧光染料在DMF、乙腈、丙酮、乙酸乙酯和乙醚5种溶剂中的荧光光谱和吸收光谱,发现由于溶剂效应,随溶剂极性由小到大,荧光光谱和吸收光谱的最大峰值波长逐渐红移。考察了不同金属离子和pH对荧光染料荧光光谱的影响,结果表明荧光强度随Fe3+、Zn2+、Co2+浓度增大而逐渐增强,Fe3+的影响最为显著;当pH<7时,荧光强度随着pH的降低逐渐增强;进一步考察了Fe3+、Zn2+、Co2+对吸收光谱的影响,结果发现吸收光谱均蓝移。分析认为荧光染料的光致电子转移被阻碍,实验结果表明,合成的新型荧光染料可用于溶液中金属离子和pH的检测。

Synthesis and Properties of 4-(2-Dimethylaminoethyloxy)-N-octadecyl-1,8-Naphthalimide-based Fluorescent Dye

Oil-soluble 4-(2-dimethylaminoethyloxy)-N-octadecyl-1,8-naphthalimide was synthesized using 4-bromo-1,8-naphthalic anhydride as starting materials through the imidization and substitution reaction.The final product was characterized by IR and 1H NMR.The flurorescecne and absorption spectra of fluorescent dye in different solvents including DMF,acetonitrile,acetone,ethylacetate and ether were measured.It was found that the maximum wavelengths of absorption and fluorescence spectra changed along with the variation of the polarity of solvent.The influence of different metal ions and pH on the spectra of dye was investigated.Results showed that fluorescence intensity increases gradually with Fe3+,Zn2+ and Co2+ concentrations strengthening.In the same concentration,the influence of Fe3+ upon fluorescence intensity of the dye in acetonitrile is the most significant.When pH< 7,fluorescence intensity strengthens gradually with the pH reducing.We further investigated the effect of Fe3+,Zn2+,Co2+ on the absorption spectrum and found the absorption spectral blue shift,which might due to impending of the photoinduced electron transfer of the fluorescent dye.The results showed that the as-synthesized dye can be used for detecting of metal ions and pH in solution.