Heavy-metal pollution is a serious environmental problem. The development of an adsorbent with the ability to bind a diverse range of toxic metal ions would make the water purification process more economically efficient. Various polysulfide materials have been reported to capture mercury efficiently, but there have been relatively few studies on the potential of these materials to bind other toxic metals at the same time. In this work, bipyridine-containing polysulfides have been synthesized for the first time by inverse vulcanization between elemental sulfur and a dioleyl bipyridine (DOBP) derivative. The incorporation of the bipyridine motif into polysulfide copolymer was verified through characterization via NMR, Fourier transform infrared (FT-IR), and Raman spectroscopy techniques. In addition, a facile and inexpensive method for creating microporous structures in polysulfide materials has been developed using sodium bicarbonate as the CO 2 -foaming agent. The developed foaming protocol provided a weakly basic solution during the salt-leaching step that caused partial ester hydrolysis of the DOBP component in poly(S 40 -r-DOBP 60 ) and conveniently installed additional alcohol and carboxylic acid groups in the polysulfide, confirmed by the presence of a broad O−H stretch in the corresponding FT-IR spectra. The metal adsorption experiment of bicarbonate-foamed poly(S 40 -r-DOBP 60 ) with a multielement solution indicated 82−100% removal of 11 toxic metal ions

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Source of materialFreshly prepared CdCO 3 (0.17 g, 0.99 mmol), 2,2¢-bipyridine (0.08 g, 0.51 mmol), 4-chlorobenzoic acid (0.12 g, 0.77 mmol), 12 mL CH 3OH/H2O (1:2 v/v) were mixed and stirred for ca. 4.5 h. Subsequently, the resulting suspension was heated in a 23 ml Teflon-lined stainless steel autoclave at 393 K for 6 day. After the autoclave was cooled to room temperature, the solid was filtered off. The resulting colorless filtrate was allowed to stand at room temperature and slow evaporation for two months afforded red blockshaped crystals. Experimental detailsWhile H atoms bonded to C atoms were treated under using riding rigid-body approximations and restrained U iso values, all water H atoms were found from Fourier difference maps and refined freely. DiscussionThe title crystal structure is similar to the structures of bipyridinecadmium(II) salicylate,