Microstructural Modulation of Isomorphic Luminescent Coordination Polymers To Achieve Sensing Effect Transformation
Jinfang Zhang, Xingyu Tao, Shuaixing Wang, Yinlong Yue, Dejing Yin, Chi Zhang
Abstract
The sensing effect transformation is first exploited by microstructural modulation. Two AIE functional ligands L-1 and L-2 were developed to construct two isomorphic coordination polymers [Cu( L-1 ) 2 (SCN) 2 ] n ( 1 ) and [Cu( L-2 ) 2 (SCN) 2 ] n ( 2 ), respectively ( L-1 = 4,4′-((9 H -fluoren-9-ylidene)-methylene)dipyridine; L-2 = 5,5′-((9 H -fluoren-9-ylidene)-methylene)dipyrimidine). 1 and 2 exhibit 1-D single-chain architectures and have good water, pH, and thermal stabilities. 1 and 2 show the functional-ligand-originated luminescence and reduced emission intensities. L-1 and L-2 stack in a back-to-back manner in 1 and 2 with the distances of 4.61 and 5.38 Å, resulting in distinct MnO 4 – sensing effects for 1 and 2 . 1 exhibits “turn-off” (luminescence quenching) MnO 4 – sensing. In a sharp contrast, 2 shows “turn-on” (luminescence enhancing) MnO 4 – sensing ability with ultrahigh sensitivity. Particularly, 2 represents the first “turn-on” MnO 4 – sensor. Their sensing mechanism toward a distinct MnO 4 – sensing effect is discussed in detail.