Structural Diversity and Fluorescent Sensing for Antibiotics and Nitrobenzene of Cd‐Based Sensors With Three Tricarboxylate Isomers

ABSTRACT Three novel Cd (II) coordination polymers (Cd‐CPs) ( 1–3) , with the formula of [Cd(2‐DBB)(1,4‐bibz)(OH)]·H 2 O( 1 ), [Cd 3 (3‐DBB)(1,4‐bibz) 2 ]·2H 2 O( 2 ), and [Cd(4‐HDBB)(1,4‐bibz) 0.5 ]( 3 ) based on three soft organic isomers: n ‐(3,5‐dicarboxylato benzyloxy) benzoic acid ( n = 2, 3, or 4‐H 3 DBB), and one linear N‐donor ligand 1,4‐bis(1‐imidazoly) benzene (1,4‐bibz) have been synthesized hydrothermally and characterized by X‐ray single crystal diffraction, elemental analyses, thermogravimetric, UV, IR, and PXRD technologies. The significant structural differences are both coordination polymers 1 and 3 featuring 2D networks, but 2 with 3D framework due to the change of H 3 DBB isomers. Despite structural differences, the series of Cd‐CPs exhibits similar fluorescence sensing properties for nitrobenzene (NB) with low detection limits of 1.05 μM ( 1 ), 44.3 nM ( 2 ), and 59.1 nM ( 3 ), respectively. However, these Cd‐CPs have been discovered to detect different antibiotics, respectively: 1 had a quenching effect on ornidazole (ONZ) but 2 and 3 on chloramphenicol (CHI). The results of the theoretical calculation verified the fluorescence detection mechanism by these Cd‐CPs. Therefore, these Cd‐CPs might be potential luminescent sensing materials for antibiotics and NB in the future.