【作者】 朱玉荣；

【导师】 李斌；

【作者基本信息】 东北师范大学 ， 无机化学， 2011， 硕士

【摘要】 随着社会的发展,重金属离子污染已成为全世界共同关注的一个课题。在重金属离子污染中,Cr³⁺污染污染日益严重,但是以往的研究方法,诸如原子吸收,原子发射及生物吸附,它们共同的缺陷就是样品需要预处理、灵敏度底、检测不够快速等。光传感材料就是用光信号来体现被分析物性质的一种材料。它具有方便,快捷,廉价等优点,因此被广泛应用于环境化学,临床病毒学,生物探针,食品安全及废物处理等领域。通常检测重金属Cr³⁺的光传感材料多为有机大分子化合物,合成步骤繁琐,成本昂贵且大部分为非水溶性的,因此也限制了它在实际中的应用。稀土离子除了具有特征的锐线光谱、大的斯托克位移及长的激发态寿命等优点外,还有一个很大的优势就是价格低廉,因此如果能用稀土配合物检测水溶液中Cr³⁺,那么它在很大程度上会对检测工作提供一定的理论依据。为此本论文针对这个问题开展如下工作:（1）我们用2,6吡啶-二甲酸（PDA）作为配体,合成了两个水溶性的稀土传感材料Na₃RE（PDA）₃ （RE = Eu, Tb）,通过紫外吸收,元素分析,荧光光谱等测试,发现荧光光谱的强度随着Cr³⁺浓度的增加而下降。实验结果表明,这两个配合物对Cr³⁺均具有较好的选择性,其中铽的配合物对Cr³⁺的灵敏度最高,且具有良好的线性,因此有望应用在水溶液中对Cr³⁺的检测。（2）基于上一章的结论,我们又尝试把中心稀土离子换成了Sm和Dy,并进行了一系列的测试和表征,得出了与上一章相似的结论,但是这两个配合物检测的浓度比Eu, Tb配合物低,我们推测原因可能是因为中心离子不同造成的。更多还原

【Abstract】 With the development of society, the heavy metal ion pollution has become a topic of common concern around the world. The pollution of Cr3 + is a serious problem. Although instrumental analyses such as atomic absorption or atomic emission spectroscopy （AAS or AES）, colorimetry, bio-sorption, electrochemical and potentiometric are currently used in applications relevant to the detection of chromium ion, they have sophisticated experimental methods and low sensitivity . Therefore, great attention is attached to develop selective chemosensors for chromium. Due to its simplicity, instantaneous response and high selectivity, fuorimetric detection of Cr³⁺ has great advantages over other detection techniques. So it is widely used in environmental chemistry, clinical virology, the food safety , waste treatment, etc. To our best knowledge, the reported chemosensors have some disadvantages :（1） the crude materials are expensive ; （2） the procedures are troublesome; （3） they are not water solubility,so these disadvantage prevent them from actual applications for Cr³⁺ sensors. Rare-earth （RE） based emitters have some advantage such as can give sharp, narrow emission bands, large sharpen stoke displacement, long excited lifetime and very cheap, if we can use it to detection Cr³⁺ in aqueous solution, it will provide certain theoretical basis for the actual applications to a large extent.In addition ,very few Cr³⁺ fluorescent sensors in aqueous system have been successfully designed so far.First: Tow water soluble rare-earth （Ⅲ） fluorescent chemosensors of Na₃RE（PDA）₃ （PDA = pyridine-2,6-dicarboxylic acid; RE = Eu, Tb,） have been synthesized and characterized by UV/Vis absorption, elemental analysis, and fluorescence spectra. It is observed that their emission intensity and excited state lifetimes decrease with increasing concentration of trivalent chromium (Cr³⁺). Their sensing behavior towards Cr³⁺ is investigated by fluorescence spectroscopy. Results suggest that Na₃Tb（PDA）₃ exhibits the highest sensitivity and linear spectral response towards Cr³⁺ （Stern-Volmer constant = 0.829×10⁶ L/mol, linearity = 0.989）. These important advantages make themselves promising candidates to be utilized in actual applications.Second: We tried to put center rare earth ions replaced by Sm and Dy, and conducted a series of tests and characterization.Then we obtained the similar conclusion, but the two complexes’s detect limit is lower than Eu and Tb complexes .we speculate the reasons may be is the difference of central ions.更多还原