The Synthesis Of Tripodal Compounds And Their Application In Fluorescent Probes

Cations and anions are ubiquitous exist in organism and environment. They play an significant roles in biology, environmental science, medicine and chemical processes.Meanwhile, humans had already realized the effects of cation and anion on environmental pollution and human's health. Therefore, it is essential to development a rapid, sampling and lower cost analytical method that can be widely used in environment science, biological and clinical medicine area to determination of ions.Fluorescence method has the advantages of high sensitivity, high selectivity, simple and quick, real-time in situ detection and visualization. fluorescent chemosensor has received considerable interest and has been widely application in the recognition of ions and neutral molecules as well as the vivo cell imaging.For all the above reasons, at the First the thesis, we simply introduces the structure of fluorescent probes, identification and fluorescence response mechanism. Then further reviewed the research history and recent development of the Rhodamine-based probes, espercially the advance of the tripod fluorescent probes.Because of excellent coordination recognition abilities, shielding effect to coexisting ions during molecular recognition process and easy modification, The tripodal scaffold seems to be an ideal candidate for construction of multi-analytes fluorescent probe. However, the reported tripodal fluorescent probes also have some disadvantages such as interference of recognition and transmission signal, Meanwhile,we also need to looking for some new mechanism to constructure multi-analyte chemosensors. Based on above reasons, we designed and of synthesis three types of tripodal fluorescence probes And two main aspects of the research work was made as follow.Firstly, utilized the advantage that the three free aminos of Tris(2-aminoethyl)-amine can be easily modified, two tripod fluorescent probes are designed andsynthesized and both of them contained only one kinds of fluorophores, another seven probes contained two different fluorophores and four probes contain three different fluorescent groups are also synthesized. Their structures were characterized by NMR,ESI-MS, IR analysis to confirm the structure of design and synthesis.The recognition properties of these probes to ions were investigated by absorption spectra and fluorescence spectra. Finally, Research results shows that probe 4 can be a excellent dual channel chemosensor. It can used as UV chemosensors simultaneously and selectively recognition of Co2+, Fe3+ and Cu2+. To act as fluorescent probe to selectively recognize Zn2+, Hg2+, Al3+ and Cu2+. The mechanism for sensing multi-analytes was suggested as the rhodamine spirolactam and ring-opened, C=N isomerization-CHEF mechanism combined with the FRET mechanism. Probe 4 has shown high sensitivity and selectivity, real-time detection ability and remarkable membrane permeability under physiological conditions. Probe 4 can also be used for monitoring intracellular Zn2+, Cu2+, Hg2+ and Al3+ levels in living cells. The probe 7can be used not only as the Al3+ and I- of highly sensitive fluorescence chemosensors but also colorimetric chemosensors.