螺吡喃光响应的汞、铬、银离子探针及相互作用光谱

Spiropyran-Based Fluorescent Sensor for Hg^(2+),Cr^(3+),Ag^+ and Their Interaction Spectra

合成并表征了1-羟乙基-3,3-二甲基-6′,8′-二叔丁基吲哚啉苯并螺吡喃配体1及其衍生物配体2。由于苯并螺吡喃6′,8′-二叔丁基斥电子基团的电子效应,开环体部花菁酚氧负离子上的负电荷难以分散,使其结构不稳定,配体1在紫外光照射下不直接开环,只有在极性较强的甲醇溶剂中受适当金属离子诱导才能形成有色开环体部花菁结构形式。配体1能较好地选择识别Hg2+,Cr3+和Ag+。当其相互作用时,不但紫外可见光谱及荧光光谱有明显"turn-on"变化,而且体系颜色明显地由无色变成黄色,目视识别效果直观明显。其他金属离子的存在对Ag+,Cr3+和Hg2+的识别几乎没有干扰。配体1与Ag+,Cr3+和Hg2+络合的化学计量比均为1∶1,检出限分别是:7.435 8×10-6,6.126 8×10-6,3.452 4×10-6 mol.L-1。通过配体2进一步证明了配体1和金属离子识别的结合模式。即螺吡喃结构中N1位取代侧链上的羟基,和其开环体酚氧负离子相互协调并与金属离子结合。

A 6′,8′-di-tert-butyl-1-hydroxyethyl-3,3-dimethyl-indoline benzospiropyran L1and its derivative L2 were synthesized and characterized.Chelation-enhanced appearswhen L1 with electron donating groups of 6′,8′-di-tert-butyl touch on benzospiro——pyran and affect the stability of cyanine structure.L1 exhibited high selectivity to Hg2＋,Cr3＋,Ag＋ over other metal ions.While,there was no obvious interferences of coexist metal ions on Hg2＋,Cr3＋,Ag＋ detection.The Hg2＋,Cr3＋,Ag＋ recognition of L1 not only could be achieved by means of fluorescense and absorption ＂turn-on＂ spectra but also an obvious color change from colorless to yellowish by naked-eyes.The binding of L1 to Ag＋,Cr3＋,Hg2＋ are in 1∶1 stoichometry and the detection limits are 7.435 8×10-6,6.126 8×10-6,3.452 4×10-6 mol·L-1.The sensing mechanism was also investigated from L2.