新型吡啶鎓盐分子的合成及其对Fe^(3+)的检测

Syntheses of novel pyridinium salt and its performance on ferric ion detection

针对水中铁离子(Fe^(3+))检测存在使用有毒溶剂、对设备要求较高、检测限高等缺点,以四联吡啶和5-溴甲基-间苯二甲酸二甲酯为原料,以N,N-二甲基甲酰胺为溶剂,通过亲核取代和水解反应制备出一种新型的铁离子检测探针——吡啶鎓盐分子。运用一系列的表征技术分析了吡啶鎓盐分子的性质,并通过实验探察了共存离子、Fe^(3+)的浓度等对吡啶鎓盐分子识别Fe^(3+)的影响。表征实验结果表明,吡啶鎓盐分子结构具有三齿吡啶氮和羧基,使其与Fe^(3+)之间具有很高的亲和力,可以与Fe^(3+)配位形成金属络合物。识别实验结果表明,吡啶鎓盐分子对Fe^(3+)的络合显色实现了对Fe^(3+)的专一性检测,其检测限为4.8×10^(−7)mol·L^(−1);在Cd^(2+)、Zn^(2+)、Mn^(2+)、Ni^(2+)、Cu^(2+)、Fe^(2+)和K^(+)等多种干扰离子存在条件下,对Fe^(3+)仍具有良好的识别效果,体现出较强的抗干扰性能。综上所述,新型吡啶鎓盐分子结构中具有三齿吡啶氮和羧基,使其对水中Fe^(3+)具有易识别、灵敏度高、选择性好等优点。

To solve the problems existing in the process of Fe^(3+) detection,such as the used toxic solvents,high requirements for equipment and high detection limit,a novel Fe^(3+) detection probe-pyridinium salt molecule was prepared by nucleophilic substitution and hydrolysis reaction when tetrapyridine and dimethyl 5-bromomethylm-phthalate were taken as raw materials and N,N-dimethylformamide was taken as solvent.A series of characterization techniques were used to analyze the properties of pyridinium salt,and the effects of coexisting ions and Fe^(3+) concentration on Fe^(3+) recognition by pyridinium salt molecule were investigated.Characterizing experimental results showed that pyridinium salt molecular structure had tridentate pyridine nitrogen and carboxyl groups,which presented a high affinity with Fe^(3+) and could form metal complexes through coordination with Fe^(3+).The detection experimental results indicated that the specific detection of Fe^(3+) was achieved by complex chromogenic of pyridinium salt in the presence of Fe^(3+),and the detection limit was about 4.8×10^(−7)mol·L^(−1);No change occurred in the probe signal in the presence of multiple interfering ions,such as Cd^(2+),Zn^(2+),Mn^(2+),Ni^(2+),Cu^(2+),Fe^(2+),K^(+) and so on,showing good specific detection for Fe^(3+).In conclusion,the novel pyridinium salt has the advantages of easy recognition,high sensitivity and good selectivity to Fe^(3+) in water due to its tridentate pyridine nitrogen and carboxyl groups.