席夫碱的合成、晶体结构与荧光探测性质研究

发布时间：2019-05-17 12:57

【摘要】：我们设计并合成了两个基于ICT和CHEF机理的荧光传感器H_2L~1(肟基)和H_2L~2。H_2L~1是一个四齿双功能配体,并且它可以合成四核的配合物。传感器H_2L~1和H_2L~2由于分子内PET机理而表现出较低的比色荧光,当按照一定比率加入Zn~(2+)后,溶液的荧光发射强度增强,产生荧光响应,随着Zn~(2+)浓度的降低,荧光发射强度减弱。实验结果表明,该传感器对Zn~(2+)的荧光选择性较强,超过其他金属离子,尤其是Cd~(2+)。据报道,Cd~(2+)和Zn~(2+)有相似的化学特性,易产生干扰,传感器H_2L~1可用于对Cd~(2+)和Zn~(2+)的选择性识别,此外,传感器H_2L~2可以对Cu~(2+)进行选择性识别。传感器H_2L~1的结构表明它可以和多种金属离子配位形成稳定的配合物,配体分子的设计具有双N2O2螯合基团,使它可以与四个金属离子配位,紫外-可见光谱中观察到的四个等位点进一步证实了这个结论,结果表明它们的化学计量比为1:1。Zn~(2+)和Ni~(2+)分别与传感器H_2L~1以1:1的配比形成稳定的配合物,并且它们都是五配位的构型。Zn~(2+)和Ni~(2+)与H_2L~1所形成的配合物的荧光光谱、紫外-可见光谱和晶体结构都证实了Zn~(2+)和Ni~(2+)与传感器H_2L~1的配位比为1:1。斯托克位移是衡量荧光灵敏度的一个很重要的指标,传感器H_2L~1识别Zn~(2+)时,有一个很大数值的斯托克位移,使得这个识别效果非常明显。总的来说,这两个传感器表现出高灵敏的选择性和化学可逆性,所以,它们可以被应用到生物和环境系统中对Zn~(2+)和Cu~(2+)进行选择性识别。[H_2L~1]?C_6H_3N_3O_7:化学组成为C22H19N5O10,Mr,513.42,属于三斜晶系,空间群P-1,晶胞参数:a=7.214?,b=14.102?,c=14.279?,α=114.563°,β=91.226°,γ=99.421°,Z=2,V=1296.9?3,R1=0.1437,wR2=0.2706.[Zn_4(L_4)]:化学组成为,C_(64)H_(56)N_8O_(12)Zn_4,Molecular weight,1390.73,属于四斜晶系,I41/a,Cell parameters:a=21.9438(3)?,b=21.9438(3)?,c=12.4417(3)?,α=90°,β=90°,γ=90°,Z=4,V=5991.1(2)?3,R1=0.0525,wR2=0.1497.[Ni_4(L_4)]:化学组成为C_(64)H_(56)N_8O_(12)Ni_4,Molecular weight,1363.93,属于三斜晶系,P-1,Cell parameters:a=13.2898(8)?,b=14.7012(8)?,c=16.7421(9)?,α=81.534(5)°,β=67.214(5)°,γ=72.519(5)°,Z=2,V=2874.7(3)?3,R1=0.0759,wR2=00.1220.[H_2L~2]:化学组成为C_(15)H_(13)NO_3,Molecular weight,255.26,属于单斜晶系,P 21/c,Cell parameters:a=7.5158?,b=6.3940?,c=25.881?,α=90°,β=93.243°,γ=90°,Z=4,V=1241.8?3,R1=0.0547,wR2=0.1350.
[Abstract]:We designed and synthesized two fluorescent sensors H_2L~1 and H_2L~2.H_2L~1 based on ICT and CHEF mechanism, which are four-toothed bifunctional ligands, and they can synthesize tetranuclear complexes. The sensors H_2L~1 and H_2L~2 showed low colorimetric fluorescence due to the mechanism of intramolecular PET. When Zn~ (2) was added at a certain ratio, the fluorescence emission intensity of the solution increased and the fluorescence response was produced, with the decrease of Zn~ (2) concentration. The intensity of fluorescence emission is weakened. The experimental results show that the fluorescence selectivity of the sensor for Zn~ (2) is stronger than that of other metal ions, especially Cd~ (2). It is reported that Cd~ (2) and Zn~ (2) have similar chemical properties and are prone to interference. The sensor H_2L~1 can be used for selective identification of Cd~ (2) and Zn~ (2). In addition, The sensor H_2L~2 can selectively identify Cu~ (2). The structure of the sensor H_2L~1 shows that it can coordinate with a variety of metal ions to form stable complexes. The ligand molecules are designed with double N2O2 chelating groups so that they can coordinate with four metal ions. This conclusion is further confirmed by four equal sites observed in UV-vis spectra. The results show that their stoichiometric ratios are 1 鈮，

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