New Three-dimensional Supramolecular Cd(II)-Coordination Polymer as a Luminescent Sensor for Sulfamethazine Detection

A new luminescent three dimensional (3D) supramolecular coordination polymer (CP) with formula [Cd-2(L)(2)(bib)(H2O)(2)] (1) (H2L = 4,4 '-(1,2-phenlenebis(methyleneoxy))dibenzoic acid and bib = 1,4- bis(1-imidazoly)benzene), has been synthesized and characterized. The single crystal X-ray analysis revealed that 1 possess one-dimensional (1D) ribbon-like motifs. Through intermolecular hydrogen bonding, the motifs produced a 2D supramolecular layer and further, pi center dot center dot center dot pi interactions generated a 3D supramolecular framework. In addition, the bib linkers stretch across the loop to generate a polyrotaxane-like structure. Polymer 1 behaves as a luminescent sensor for antibiotics, it sensitively and selectively detects sulfamethazine (SMZ) with a low detection limit of 1.05 ppm and a high K-SV value of 2.98 x 10(3) M- 1. With the aid of theoretical calculations plausible luminescence sensing mechanism of 1 to detect antibiotics has been proposed. It is suggested that electron/energy transfer and weak CP-antibiotics interactions are responsible for variation in luminescence intensity of the polymer. [GRAPHICS] .