Synthesis Of Novel Fluorescent Probe Molecules For Nickel, Copper Or Iron Ion Detection

Fluorescent sensors can selectively transfer chemical information into fluorescent signal. Fluorescent sensors are becoming popular because of their ease of application as well as their high sensitivity to and selectivity for tracing analytes with spatial and temporal resolution. However, the application of fluorescent probes is still subject to some limitations. For example, some probes are poorly water-soluble which must be used in the organic solvents or organic solvent and water mixed solvents, some of them are lack of specificity and are susceptible to other metal ions, some probes are poor of membrane permeability, or their excitation wavelength must be in the ultraviolet band, which is restricted in biological detection. Therefore, the design, development and applications of new fluorescent probe molecules has always been a hot topic in the field of chemistry. This paper has designed and systhesized a series derivatives of pyrrolo[2,l,5-de]quinolizine, pyrrolo[2,1,5-cd]indolizine and pyrrolo[2,1-a]isoquinoline, studied fluorescence properties of these compounds, and investigated their applications in fluorescent probes.1. A series of pyrrolo[2,1,5-de]quinolizine derivatives(Ⅱ-5a～Ⅱ-5c) were synthesized and their optical properties were tested. The results showed that II-5a had selective fluorescence response to Ni2+, with low sensitivity and high selectivity. With the addition of Ni2+, the fluorescence intensity of Ⅱ-5a weakened gradually, the quenching degree was 62%. Compound Ⅱ-5a could be used as fluorescence quenched fluorescent probe for Ni2+. Job curve showed that Ⅱ-5a and Ni2+ formed 1:2 complexes.2. A series of pyrrolo[2,1,5-cd]indolizine derivatives(Ⅲ-6a、Ⅲ-6b) were synthesized and their optical properties were tested. The results showed that Ⅲ-6a、Ⅲ-6b had selective fluorescence response to Cu2+, with low sensitivity and high selectivity. Compound Ⅲ-6a、Ⅲ-6b could be used as quenched fluorescent probe for Cu2+. Job curve showed that Ⅲ-6a、Ⅲ-6b and Cu2+ formed 1:1 complexes.3. A series of pyrrolo[2,1-a]isoquinoline derivatives(Ⅳ-5a-Ⅳ-5e) were synthesized and their optical properties were tested. The results showed that Ⅳ-5a-Ⅳ-5e had selective fluorescence response to Fe3+. Through them, we found IV-5a could be used as fluorescent probe for Fe3+, with low sensitivity and high selectivity. The sensitivity of IV-5b-IV-5e to Fe3+ was not high, the structure remained to be further optimized. Job curve showed that IV-5a-IV-5e and Fe3+ formed 1:1 complexes.