羟基萘啶类铽、铕配合物发光的酸碱响应机制  

Acid-Base Response Behavior of Luminescent Terbium and Europium Complexes Based on 4-Hydroxy-1,5-naphthyridine Ligands

作　　者：卫慧波[1,2] 魏晨 缪倩倩[2] 刘志伟 卞祖强[1] 黄春辉[1] Wei Huibo;Wei Chen;Miao Qianqian;Liu Zhiwei;Bian Zuqiang;Huang Chunhui(State Key Laboratory of Rare Earth Materials Chemistry and Application,College o f Chemistry and Molecular Engineering,Peking University,Beijing 100871,China;Jiangsu JITRI Molecular Engineering Inst.Co.,Ltd.,Sunan Institute for Molecular Engineering,PKU,Changshu 215500,China)

机构地区：[1]北京大学稀土材料化学及应用国家重点实验室,化学与分子工程学院,北京100871 [2]江苏集萃分子工程研究院有限公司,北京大学分子工程苏南研究院,江苏常熟215500

出　　处：《中国稀土学报》2020年第3期424-432,I0004,共10页Journal of the Chinese Society of Rare Earths

基　　金：973计划项目(2017YFA0205100);国家自然科学基金项目(21621061);北京市教委科技计划重点项目(KZ201910028038)资助。

摘　　要：为了揭示羟基萘啶类稀土配合物发光酸碱响应的机制,测试了4-羟基-1,5-萘啶(ND)配体在不同酸碱性条件下的紫外吸收光谱和低温磷光光谱,研究不同构型配体的激发态能量变化。结果表明:与碱性条件下失去质子的烯醇式负离子(ND^-)相比,含质子的酮式结构(HND)具有更高的三重态能级,因而能显著提高敏化稀土离子的效率。利用甲基化反应构筑具有酮式结构的配体1-甲基-1,5-萘啶-4-酮(mND),其光谱表征进一步地验证了酮式构型具有比烯醇式负离子更高的三重态能级。研究表明,该类配体可以作为一种具有灵敏酸碱响应性的敏化官能团用于构筑基于稀土离子的发光pH探针。To unclose the mechanism of the acid-base response behavior of 1,5-naphthyridin-4(1 H)-one/ol(ND) based luminescent lanthanide(Ln) complex, UV-vis absorption spectra and low temperature phosphorescence spectra of the ND ligand or Ln complexes at different acid/base condition were tested. It is revealed that the keto form HND [1,5-naphthyridin-4(1 H)-one] at neutral or weak acid solution, showed higher triplet energy level than that of the deprotonated enol anion(1,5-naphthyridin-4-olate, ND^-) at base condition. Therefore, upon addition of HCl, the enol anion ND-gradually transformed to keto form HND, and thus sensitization of the lanthanide ion is successfully turned on. It is indicated that such ligand is a potential functional group for constructing sensitive pH sensors based on luminescent lanthanide ions.

关 键 词：4-羟基-1 5-萘啶 稀土发光 酸碱响应 pH探针 

分 类 号：O616[理学—无机化学]