Synthesis, structural characterization, antibacterial activity and selective dye adsorption of silver (I)-based coordination polymers by tuning spacer length and binding mode of chromate anion

Abstract

Two silver-based coordination polymers, {[AgL4]2[CrO4]}n (1) and {[Ag2(L3)(CrO4)]·CH3OH}n (2) (L4 ​= ​1,1′-(butane-1,4-diyl) bis(3-methylimidazoline-2-thione) and L3 ​= ​1,1′-(propane-1,3-diyl)bis(3-methylimidazoline-2-thione)) have been successfully prepared and fully characterized via single crystal X-ray diffraction, powder X-ray diffraction (PXRD), FT-IR spectra, elemental analysis (CHN) and thermo gravimetric analysis (TGA). Polymers 1 and 2 present different structures due to the flexiblity of the thione ligands L4 and L3 in directing the coordination mode of chramate and hence dimension of the considered polymers. The flexiblity of the ligands have no effect on the coordination geometry around the silver atoms. In contrast to the 3D CP-1, in polymer 2 hydrogen bonding interactions between the oxygen atoms of CrO42− anions and hydrogen atoms of the methylene groups of the spacer of the ligand forming a 3D supramolecular network. These compounds be able to absorbed Aniline blue (AB) as anionic dye from aqueous solution with a maximum adsorption capacity of 227.73 and 219.95 ​mg ​g−1 for 1 and 2, respectively. Therefore,polymer 1 has a slightly more efficiently than polymer 2. Three adsorption kinetic and isotherm models were investigated. The synthesized polymers possess antibacterial activity against the selected strain of Gram-negative and Gram-positive bacteria.