The Synthesis Of Phenanthroimidazole, Rosamine, And Coumarin Derivatives And Application In Fluorescent Probes

The advantages of fluorescence chemosensors are high sensitivity, selectivity, "on-off" switchability, observation in the naked eye, detection by using optical fibres and so on. In this study, The phenanthroimidazole ratiometric fluorescent hypochlorite probe based on ICT has been designed; The steady rosamine fluorescent Cu2+probe based on the bulky isopropyl silane group has been designed; The coumarin caged rosamine probe based on the photolysis of the 4-methylcoumarin has also been designed.To our best knowledge, aldehyde groups can be protected as oximes, which can rapidly deprotected by hypochlorite under mild conditions. So we designed and synthesized phenanthroimidazole ratiometric fluorescent hypochlorite probe based on ICT. When ClO~- added to the solution of probe, the oxime group could be removed by ClO~- to give the aldehyde group. Because the electron withdrawing ability of the aldehyde group is stronger than that of the oxime group, we detected that the emission of the probe have a red-shift due to the stronger ICT. The ClO~-probe are high sensitivity, selectivity and no interference, so phenanthroimidazole ratiometric fluorescent hypochlorite probe based on regulation of the electron withdrawing ability of the electron acceptor in the ICT system is significative.We designed and synthesized the rosamine fluorescent Cu2+probe based on the bulky isopropyl silane group can contribute to the stability. When probe was titrated with increasing concentrations of Cu2+, a drastic increase in the featured emission of conjugated rosamine around 580nm was observed, and the fluorescence intensity enhancement was up to 100-fold. The probe has been employed to sense Cu2+in Yue Lu spring, new born calf serum, and the living system based on the sensitivity of the probe. We proposed that the unprecedented copper-mediated dihydrorosamine oxodation reaction employed for the probe development likely proceeds by a copper redox mechanism. And the general metal-mediated redoxtion approach could be important in the develop bio-compatible fluorescent probe for various metal ions.The coumarin caged rosamine probe has been designed and synthesized. We first designed the probe for rosamines based on new photocaging chemistry that 4-methylcoumarin caged could release the rosamine. The probe could release rosamine and coumarin for living cell fluorescence imaging under the photoactivation by visible light, and can be employed for spatial control imaging in the living cells. Thus, these highly favorable photochemical properties should render the novel caged probes as powerful chemical tools for studies of the spatiotemporal dynamics of a wide variety of biological processes.