Synthese, structure of three Zn-MOFs and potential sensor material for tetracycline antibiotic in water: {[Zn(bdc)(4,4′-bidpe)]·H2O}n

Abstract

Recently, enough attention has been paid to the pollution and damage of antibiotics in water. Zn-metal organic frameworks (Zn-MOFs), as a novel kind of sensing material, have been tentatively developed a highly effective candidate to detect antibiotics in water. A series of Zn-MOFs material named {[Zn (bdc)(4,4′-bidpe)]·H2O}n (1), {[Zn3 (bdc)2 (tib)2(HCOO)2]·4(H2O)·0.5(CH2Cl2)}n (2), [Zn (bdc)(bidpa)]n (3) were successfully constructed under the condition of solvothermal, using 4,4′-bis(imidazolyl)diphenyl ether (4,4′-bidpe), 1,3,5-tirs (1-imidazolyl)benzene (tib), 4,4′-bis(imidazolyl)diphenyl amino (4,4′-bidpa) and 1,4-benzenedicarboxylate (H2bdc). Three complexes were characterized by X-ray single-crystal diffraction, elemental analysis, IR spectra and thermogravimetric (TG) analysis. Complex 1 has a three-dimensional (3D) framework that crystallizes in the triclinic system, Pī space group. Complex 2 crystallizes in the monoclinic system, C2/c space group featuring a 3-nodal (3,3,4)-connected network with point symbol of 2{83}2{86}{8.102}. Complex 3 belongs to the tetragonal system, I41/acd space group with two-fold interpenetrating architecture. A linear pH sensing of complex 1 (I ​= ​1035.2 pH ​+ ​726.9) between the fluorescence intensity and pH values was achieved through the fluorescence quenching experiment in the acidic condition. The fluorescence quenching experimental results showed that complex 1 exhibits sensitive response to TC with detection limit of 3.72 ​× ​10−7 ​M based on its effective spectral overlap and adsorption preconcentration with tetracycline (TC).