Two new luminescent Cd(II) coordination polymers displaying high sensitivity for norfloxacin

Abstract

Two new ternary Cd(II) coordination polymers (CPs), namely, [Cd(DCTP)0.5(L)2(SO4)0.5]n (1) and [Cd(DCTP)(L)]n (2) (L = 2-(4-thiazolyl) -1H-benzimidazole; H2DCTP = 2,5-dichloroterephthalic acid), were successfully synthesized using the solvothermal method. 1 displays a 1D zigzag infinite chain, which can be further extended into the 2D network via classic hydrogen bonding interactions in a triclinic system (unit cell parameter: a = 9.251(2) Å, b = 11.194(3) Å, c = 12.865(3) Å. α = 105.362(2)°, β = 97.871(2)°, γ = 98.229(2)°). 2 is a (3,4)-connected 2D layer that is subsequently expanded into a 3D supramolecular framework through π···π stacking interactions in a triclinic system (a = 9.161(3) Å, b = 9.225(4) Å, c = 12.575(4) Å. α = 89.554(3)°, β = 69.446(3)°, γ = 68.858(4)°). Both CPs demonstrate exceptional stability in the wide pH range of 3−12. Furthermore, 1 and 2 can act as exceptional luminescent probes for the sensing of norfloxacin with low limits of detection (2.03 × 10−9 mol/L for 1 and 4.88 × 10−8 mol/L for 2) and remarkable anti-interference abilities. Moreover, the mechanisms of the luminescence quenching of CPs are investigated.