苯并噻唑类探针取代基结构对金属离子识别性能的影响  

Effect of Substituent Structure of Benzothiazole Probe on Recognition to Metal Ion

作　　者：贾慧劼[1] 竺宁[1] 高媛媛[1] 王亚琦[1] 索全伶[1] JIA Hui-jie;ZHU Ning;GAO Yuan-yuan;WANG Ya-qi;SUO Quan-ling(Chemical Engineering College,Inner Mongolia University of Technology,Huhhot 010051,China)

机构地区：[1]内蒙古工业大学化工学院,内蒙古呼和浩特010051

出　　处：《光谱学与光谱分析》2020年第11期3594-3598,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(21762032)资助。

摘　　要：荧光探针对识别金属离子具有检测快、选择性好等特点,设计合成了两个苯并噻唑类探针分子6-(3,5-二甲基苯氧基)-5-胺基-2-苯基苯并噻唑(L4)和6-(3,5-二甲基苯氧基)-5-苯甲酰胺基-2-苯基苯并噻唑(L5),并通过探针分子的紫外可见光谱和荧光光谱的变化特征,详细研究了探针L4和L5对溶液中三价金属离子Al^3+, Fe^3+, Cr^3+和二价金属离子Cu^2+的识别性能。研究结果表明,当L4分子中的识别基团胺基与苯甲酰基键合形成L5分子结构时,会发生荧光猝灭,同时获得了开启式荧光探针L4和关闭式荧光探针L5。紫外可见光谱检测结果表明,在有机溶液中,探针L4选择性地识别出Al^3+, Fe^3+, Cu^2+;在含水乙腈溶液中,探针L4高选择性地识别出Cu^2+;通过紫外光照射下的裸眼检测,含探针L4的试纸有效地识别出纯水中的Cu^2+;在有机溶液中,探针L5选择性地识别出Al^3+和Fe^3+。荧光光谱检测结果表明,当探针L4与Fe^3+, Al^3+, Cu^2+存在于有机溶液中时, L4将发生荧光猝灭;在含水乙腈溶液中,探针L4对Cu^2+具有高选择性识别作用;当探针L5与Cr^3+, Fe^3+, Al^3+, Cu^2+存在于有机溶液中时, L5的荧光强度依次增强。利用溶液浓度对吸收强度作图,计算出了探针L4对Cu^2+的检出限为4.51×10(-6) mol·L^-1,络合常数Kα为1.12×103 M^-1;探针L5对Al^3+, Cr^3+, Fe^3+, Cu^2+的检测限分别为2.85×10^-6, 4.79×10^-6, 5.95×10^-6和3.23×10^-6 mol·L^-1,络合常数分别为:Kα(Al^3+)=2.17×10^3 M^-1,Kα(Cr^3+)=2.06×10^3 M^-1,Kα(Fe^3+)=3.92×10^3 M^-1,Kα(Cu^2+)=4.43×10^3 M^-1。根据探针与识别金属离子的荧光滴定实验结果,推测出探针分子与金属离子之间形成了1∶1络合物。抗金属离子干扰实验结果表明,探针分子对特定金属离子的识别基本不受其他干扰金属离子的影响。1H NMR滴定结果表明,探针L4分子结构中胺基和二甲基苯氧基,探针L5分子结构中的苯甲酰胺基和二甲基苯氧基取代For the characteristics of fast detection and good selectivity about fluorescence probe for recognition to metal ions,the synthesis of probes 6-(3,5-dimethyl phenoxy)-5-amine-2-phenylbenzothiazole(L4)and 6-(3,5-dimethyl phenoxy)-5-benzamide-2-benzothiazole(L5)was designed.The molecule structures of L4 and L5 were confirmed by spectroscopic characterization and single crystal diffraction analysis.The effects of probes L4 and L5 on recognizing to trivalent metal ions Al^ 3+,Cr ^3+,Fe ^3+and divalent metal ion Cu^ 2+in the solution were investigated in detail by UV-Vis and fluorescence.The results showed when the molecule of probe L5 was formed by the benzoyl recognizing group bonding with the amine group of probe L4,the fluorescence of probe L4 was quenched,and the turn-on fluorescent probe L4 and the turn-off fluorescent probe L5 were simultaneously obtained.The UV-Vis results show that probe L4 could selectively identify to Al^3+,Fe^3+,Cu^2+in the organic solution and highly selectively identify to Cu^2+in the aqueous acetonitrile solution.A test paper of probe L4 could effectively identify to Cu 2+in pure water by the naked eye detection under UV irradiation.Probe L5 could selectively identify to Al^3+and Fe^3+in the organic solution.The fluorescence results show the fluorescence of probe L4 was quenched while probe L4 with Fe^3+,Al^3+,Cu^2+were coexisted in the organic solution,respectively.Probe L4 could highly selectively recognize to Cu^2+in the aqueous acetonitrile solution.The fluorescence intensity of probe L5 was successively increased while probe L5 with Cr^3+,Fe^3+,Al^3+and Cu^2+were coexisted in the organic solution,respectively.According to the L4 solution concentration to the absorption intensity was plotted,and the detection limit of probe L4 to Cu^2+is 4.51×10^-6 and the complex constant is 1.12×10^3 M^-1.The detection limits of probe L5 to Al^3+,Cr^3+,Fe^3+,Cu^2+are 2.85×10^-6,4.79×10^-6,5.95×10^-6 and 3.23×10^-6 mol·L-1,respectively,and the complex constants of probe L5 to Al^3+,Cr^3+,Fe^

关 键 词：苯并噻唑 离子识别 荧光探针 荧光猝灭 

分 类 号：O657[理学—分析化学]