Isostructural Coordination\nPolymers of Zn(II) or Co(II)\nfrom Assembling of Cationic and Anionic Parts and Their Utilities

Two isostructural cobalt(II) and zinc(II) 1D-linear coordination\npolymers of 2-isonicotinoyl-N-tosylhydrazinecarboxamide (H<sub>3</sub><b>itca)</b> composed of assembled anionic and cationic parts\nin their respective chain were characterized. Their utility as adsorbent\nwas investigated. The anionic portion of the coordination polymers\ncomposed of [M(Hitca)<sub>2</sub>]<sup>2‑</sup> was bridged\nby the cationic part [M(H<sub>2</sub>O)<sub>4</sub>]<sup>2+</sup> (M\n= Co<sup>2+</sup> and Zn<sup>2+</sup>). The hydrolytically stable\nzinc coordination polymer was insoluble in water and had a lower molar\nconductance (23.5 S m<sup>2</sup> mol<sup>–1</sup>) in water,\nwhereas the cobalt coordination polymer was soluble in water and had\na molar conductance of 100 S m<sup>2</sup> mol<sup>–1</sup> that corresponded to an ionic species, showing its dissociation\nin solution. It was also confirmed by mass spectrometry. The crystals\nof both coordination polymers belong to P<sub>2</sub>/n, with crystallographic\nsimilarity index unity. The zinc coordination polymer had the ability\nto adsorb select cationic dyes methyl-violet and methylene-blue with\nabsorption capacities of 53.00 and 52.25 mg/g, respectively. It selectively\nadsorbed methylene-blue or\nmethyl-violet from the corresponding mixture of these two dyes in\naqueous solution. On the other hand, the cobalt coordination polymer\nwas not suitable for dye adsorption, but useful in the displacement\nof intercalated ethidium bromide from calf-thymus DNA effectively.