基于动态组合化学的重金属离子催化信号放大

构建了一个简单的亚胺席夫碱动态体系,应用吸收光谱法研究了二价过渡金属离子Zn2+、Cd2 +存在时席夫碱各动态组分之间的胺交换过程.实验表明,金属离子与脂肪胺席夫碱的亚胺氮原子的配位结合,活化了亚胺碳原子,有利于芳香胺的亲核取代反应,进而提高了该动态过程的动力学过程,动力学影响成为制约动态平衡的主要因素.研究还表明,金属离子的循环催化作用极大地促进了脂肪亚胺向芳香亚胺转换,即微量金属离子的引入,便能使动态过程的反应速率和转化率发生显著变化,增强转换过程中的光学输出信号,达到信号放大的目的.

Heavy Metal Ions Catalyzed Signal Amplification Based on Dynamic Combinatorial Chemistry

A simple dynamic combinatorial library(DCL) of Schiff bases was constructed that allow the use of absorption spectroscopy to evaluate the amine exchange process in the DCL in the presence of heavy metal ions.Experiments establish that the imine carbon atom of the aliphatic amine Schiff base can be activated and becomes more electrophilic upon metal coordination that affords entry to sense metal ions by following the exchange reaction kinetics.Amine exchange rate in the dynamic system was found to be enhanced remarkably by the metal ions such as Zn2+ and Cd2+,and the optical signals were amplified dramatically even in the presence of a trace amount of the metal ion which suggests that a circular catalysis of the metal ions operates in the dynamic combinatorial chemistry.