Two robust Zn(II)-organic frameworks as dual-functional fluorescent probes for efficient sensing of enrofloxacin and MnO4− anions.

Selective detection of antibiotics and MnO4− is crucial for human health improvement and protecting the environment. Two stable Zn(II)-based metal–organic frameworks (MOFs) {[Zn6(L1)2(NDC)5(μ2-OH)2]·0.5H2O}n (1), and {[Zn(L2)(NDC)]·2H2O}n (2) (H2NDC = 1,4-naphthalenedicarboxylic acid, L1 = 1,5-bis(1-(pyridine-4-ylmethyl)-1H-benzo[d]imidazol-2-yl)pentane, L2 = 1,6-bis(1-(pyridine-4-ylmethyl)-1H-benzo[d]imidazol-2-yl)hexane) were successfully synthesized by adopting the mixed ligands approach. 1 is a rare 3D 3,5,6T23 framework based polynuclear complex group. 2 possesses a 2D sql layer. The two MOFs exhibit excellent chemical and thermal stability. The title compounds are promising dual-functional fluorescent sensors for detecting enrofloxacin/MnO4− anions with high selectivity and sensitivity (Ksv values toward enrofloxacin: 4.29 × 106 L mol−1 for 1 and 4.59 × 106 L mol−1 for 2 and toward MnO4−: 1.05 × 104 for 1, 5.48 × 103 L mol−1 for 2, respectively), which are the first observations of fluorescent MOFs for the sensing of enrofloxacin and MnO4− anions. [ABSTRACT FROM AUTHOR]