Fluorescence sensitively sensing on antibiotic and nitrobenzene of two diverse 2D Zn-organic networks

Abstract

Two 2D luminous zinc(II) coordination polymers have been synthesized hydrothermally with the formulas of [Zn(4-HDBB)(3-bibz)](1) and [Zn2(4-DBB) (OH)(4,4′-bbpy)1.5]·2H2O(2) (4-H3DBB = 4-(3,5-dicarboxylatobenloxy) benzoic acid, 3-bibz = 3-bis(imidazole-l-ylmethyl) benzene and 4,4′-bbpy = 4,4′-bis (imidazolyl) biphenyl), and characterized by single crystal X-ray diffraction, IR, TG and PXRD technologies. Structural analyses exhibit both of them crystallize in P-1 space group of triclinic crystal system with 2D network structures. 1 possesses the interpenetration of 2D (4,4) networks based on the cross of two kinds of 1D chains. The 2D networks of 2 featuring 1D tube-like structure are linked by the six-number-ring H-bonds clusters. Fluorescence sensing properties on antibiotic of two complexes display 1 could detect of chloramphenicol (LOD = 6.64 × 10−7 mol⋅ L-1) and the detection limit of polymer 2 for tetracycline is 1.22 × 10−7 mol⋅ L-1. Solvents detection show that nitrobenzene in water was completely quenched by all of them, and display the highly sensitive sensing for nitrobenzene with the limit of detection of 5.0 × 10−8 mol L-1(1) and 2.14 × 10−7mol·L-1(2), respectively. Through theoretical calculation, it is found that the sensing mechanism of two complexes on nitrobenzene could be mainly attributed to the photo-induced electron transfer effect (PET). The fact shows that the two complexes can be used multi-functional sensors in the future.