和传统的基于纯有机配体（ligand）或受体（ receptor）不同，基于转金属反应的配合物荧光探针在检测金属离子时不是直接通过金属和配体的作用而是转金属反应来检测金属离子。由于配合物中金属离子的屏蔽效应（shielding function），此类配合物荧光探针可能比纯有机配体具有更好的选择性，并且其检测效果受到不同的配体化学结构和中心的金属离子的影响。

Optical Chemosensors Based on Transmetalation of Salen-based Schiff Base Complexes

Inorg. Chem., 2014, 53, 3210-3219.

Jinghui Cheng,Xiaofeng Ma, Yuhui Zhang, Jiaoyan Liu, Xiangge Zhou, and Haifeng Xiang*

We report our systematic studies of novel, simple, selective, and sensitive optical (both colorimetric and fluorescent) chemosensors for detecting Al³⁺ based on transmetalation reactions (metal displacement or exchange reactions) of a series of K(I), Ca(II), Zn(II), Cu(II), and Pt(II) complexes containing different ligands of salen-based Schiff bases. Both the chemical structure of the salen ligand and the identity of the central metal ion have a tremendous impact on the sensing performance, which is mainly determined by the stability constant of the complex. Moreover, the selectivities of the salen-complex-based chemosensors are much better than those of the corresponding free salen ligands because of the shielding function of the filled-in metal ion in the complex. Therefore, the present work potentially provides a new and simple way to design optical probes via complex-based transmetalation reactions.