Two stable cadmium(II) coordination polymers for fluorimetric detection of tetracycline and Fe3+ ions

Two stable Cd(II) coordination polymers [Cd(L)(chdc)·(H 2 O)] n ( 1 ) and [Cd(L)(SA)] n ( 2 ) (L ​= ​1,6-bis(benzimidazol-1-yl)hexane, H 2 chdc ​= ​ cis -1,2-cyclohexanedicarboxylic acid, H 2 SA ​= ​suberic acid), were successfully constructed under hydrothermal condition. 1 shows that the 2D structure can be defined as a 6 3 - hcb layer. 2 displays a rare mog topological framework with the point symbol {4·6 4 ·8}2{4 2 ·6 2 ·8 2 }. 1 and 2 exhibit the high sensing capability through luminescence quenching effects. The limits of detection (LOD) of 1 and 2 for Fe 3+ are 8.8 × 10 −7 ​mol·L −1 and 1.2 × 10 −6 ​mol·L −1 , respectively. The LOD toward tetracycline (TC) for 1 is 7.6 × 10 −8 ​mol·L −1 , for 2 is 3.3 × 10 −8 ​mol·L −1 . 1 and 2 are firstly promising dual-functional fluorescent sensors based MOFs for detection of Fe 3+ and TC with high sensitivity and selectivity. In addition, 1 and 2 exhibit excellent thermal and chemical stability. Two ternary Cd(II)-organic framework were successfully synthesized and characterized, which showed good thermal and water stabilities. 1 and 2 are promising dual-functional fluorescent sensors based MOFs for detection of Fe 3+ and TC with high sensitivity and selectivity. • 2 display a rare mog topology framework with the point symbol {4·6 4 ·8}2{4 2 ·6 2 ·8 2 }. • 1 and 2 are firstly promising dual-functional fluorescent sensors for detection of Fe 3+ and TC with high sensitivity. • 1 and 2 exhibit excellent thermal stability, as well as excellent chemical stability.