[Synthesis and ion recognition function of 7-methoxy-4-methene-coumarin-monoaza-18-crown-6 (I) synthesis and spectroscopic properties].
The title reagent MMC-MAC (O5) is synthesized and characterized. Its acidic dissociation constant at ground and excited state are determined based on the changes of the absorption and fluorescence spectra in the water. According to the wavelength shift of fluorescence spectra in different solvent, the dipole moments of ground and excited state are estimated based on the molecular mechanics model using a alchemy 2000 software and the solvachromic method using the Lippert equation,the value is 3.11D and 8.13D,respectively. It's also found that fluorescence intensity of MMC-MAC(O5) aqueous solution is increased marvelously about twenty times and accompanying with delay fluorescence emit when deoxygenation from the solution by H2SO3-N+ (CH3) 4OH-. The intensity of normal fluorescence and delay fluorescence are proportional to the concentration of MMC-MAC(O5) in the range of 4 x 10(-8)-2 x 10(-6) and 2 x 10(-7)-2 x 10(-6) mol x L(-1), and the detection limits are 2 x 10(-9) and 1.3 x 10(-8) mol x L(-1) respectively.
Wu
Y
Y
Department of Chemistry, Tsinghua University, 100084 Beijing.
Li
O
O
Tong
A
A