Two bifunctional photoluminescent Zn (II) coordination polymers for detection of Fe3+ ion and nitrobenzene

摘要

Two new luminescent metal-organic coordination polymers (MOCPs) of {[Zn-6(L)(2)(H2O)(7)]center dot(DMF)(2)}(n) (1) and {[Zn(H4L)(bPY)(0.5)(H2O)(2)]center dot H2O}(n) (2) were solvothermally constructed using zinc salts and ligands (H6L = 5,5'-(propane-2,2-diyl)bis(2-hydroxyisophthalic acid), bpy = 4,4'-bipyridine). The resulted MOCPs were characterized by elemental analysis, powder X-ray diffraction, and single-crystal X-ray diffraction. Single-crystal X-ray study results reveal that compounds 1 and 2 belong to P (1) over bar and P 2(1)/n space group and show a two- and one-dimensional structure, respectively. Their photoluminescence (PL) properties and thermal properties were also studied. Interestingly, the luminescent responses of compounds 1 and 2 show highly sensitive detection of Fe3+ via an obvious fluorescence quenching. The detection limits of compounds 1 and 2 are 0.25 mu M and 0.19 mu M toward Fe3+. Compound 2 possesses a ring structure, which is big enough to allow small molecules to easily move into the crystal skeleton and interact with each other. Thus, the luminescence responses of compound 2 were investigated for various organic solvents. These results show that compound 2 has great potential to be developed as the favorable sensor for highly selective detection of nitrobenzene.