Abstract: A new one-dimensional chain-like complex, [Cd(8-aql)₂(1,5-nd)]₂·H₂O (1)(8-aql=8-aminoquinoline, 1,5-nd=1,5-naphthalene disulfonic acidroot) was synthesized using 8-aminoquinoline and 1,5-naphthalene disulfonic acid salt as ligands and NaN₃ as pH regulator by hydrothermal reaction. And it was characterized by elemental analysis, FT-IR and single crystal X-ray diffraction. Complex 1 crystallizes in the monoclinic system with P2₁/n space group, and its asymmetric unit includes half of one Cd(Ⅱ), one 8-aql, half of one 1,5-nd and one free water molecule. In complex 1, the Cd²⁺ has a distorted octahedral coordination geometry coordinated by six atoms. Meanwhile, complex 1 shows high thermal stability under 110 ℃ and displays green fluorescence at 510 nm in the solid state. The emission peak is attributed to π^*-π of ligand due to the outermost electron of Cd²⁺ is d¹⁰. The fluorescence properties of the complex in common solvents were discussed. The experimental results show that all wavelengths of the suspension fluorescent are 10 nm to 50 nm red or blue shift and the fluorescence intensity changes obviously. The complex can be used as a fluorescent probe to detect nitrobenzene in low concentration: the linear regression equation shows that the fluorescence intensity has a good linear relationship with the concentration of nitrobenzene in the range of 6.5×10^-5 mol·L^-1 to 9.5×10^-2 mol· L^-1, and the lowest detection limit of nitrobenzene is 8.73×10^-5 mol·L^-1 according to the calculation formula of detection limit. Therefore, it can be considered that complex 1 is a potential fluorescent probe for the detection of environmental pollutants nitrobenzene with high sensitivity, low detection limit and wide linear detection range.

Key words: cadmium(Ⅱ) complex, hydrothermal method, crystal structure, one-dimensional chain-like, fluorescence probe, nitrobenzene