(7-甲氧基-4-亚甲基)香豆素基-单氮杂18-冠-6的合成及其离子识别功能(Ⅰ)——合成及光谱性质

Synthesis and Ion Recognition Function of 7 methoxy 4 methene coumarin monoaza 18 crown 6(Ⅰ)——Synthesis and Sepctroscopic Properties

合成、鉴定了题示光敏离子载体（ＭＭＣ－ＭＡＣ（Ｏ５ ））。基于不同ｐＨ值水溶液中吸收和荧光光谱的变化， 计算得该试剂基态和激发态分子的酸性常数（ｐＫａ ＝ ８．８４， ｐＫａ ＝ ５．１１）。基于在不同溶剂中荧光光谱的变化， 由Ｓｏｌｖａｃｈｒｏｍ ｉｃ法， 借助Ａｌｃｈｅｍ ｙ ２０００ 量化计算软件， 估算得该分子的基态和激发态偶极矩， 分别为３．１１Ｄ和８．１３Ｄ。同时发现， ＭＭＣ－ＭＡＣ（Ｏ５ ）水溶液除氧后其荧光强度奇迹般地提高近２０ 倍， 并伴随一定强度的延迟荧光发射。其荧光或延迟荧光强度与浓度在一定范围内呈良好线性关系。检测限分别为２×１０－ ９和１．３×１０－ ８ ｍ ｏｌ·Ｌ－ １ 。

The title reagent MMC MAC(O 5) 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(O 5) aqueous solution is increased marvelously about twenty times and accompanying with delay fluorescence emit when deoxygenation from the solution by H 2SO 3 N +(CH 3) 4OH -.The intensity of normal fluorescence and delay fluorescence are proportional to the concentration of MMC MAC(O 5) in the range of 4×10 -8 —2×10 -6 and 2×10 -7 —2×10 -6 mol·L -1 ,and the detection limits are 2×10 -9 and 1 3×10 -8 mol·L -1 respectively.