A new stable porous Pr-organic framework constructed by multi-iodine-substituted aromatic polycarboxylates: Synthesis,characterization, and selective adsorption of dyes

abstract

Poly[tris(dimethylformamide)(μ3-2,4,6-triiodol-1,3,5-benzene tricarboxylic acid)-praseodymium (III)] {Pr(TIBTC)(DMF)₃}_n (1) (H₃TIBTC = 2,4,6-triiodo-1,3,5-benzene tricarboxylic acid) was synthesized by the reaction of Pr(NO₃)₃·6H₂O and H₃TIBTC at 85°C in a pyrex vial. 1 was characterized by elemental analysis, IR, UV–vis, TGA, PXRD, and atomic force microscopy analytical means. Each of the central Pr ions and the three carboxyl groups from the same ligand constitute a SBU, which is then joined by a carboxyl group to form a building block. In order to further explore the functional properties of 1, we used this compound for adsorption experiments. It is found that 1 can effectively adsorb anionic dyes in aqueous solutions. In particular, there is a good adsorption efficiency for coomassie brilliant blue R-250. Therefore, 1 shows good prospects for selective adsorption of anionic dyes from wastewater solution.     

Formation and dichroism of poly(vinyl alcohol)–iodine complex in photocurable film

The formation of polyiodine complexes was investigated in a photocurable poly(vinyl alcohol) modified N‐methyl‐4(4′‐formylstyryl)pyridinium methosulfate acetal (PVA‐SbQ), which is a photofunctional group that causes photodimerization. PVA‐SbQ films with polyiodine complexes were prepared to be photocured, iodinated and soaked in a boric acid solution. The formation of PVA–polyiodine complexes was studied during iodinating and while in the boric acid treatment through UV–vis absorption spectrometry, resonance Raman spectrometry and IR absorption spectrometry. As a result, polyiodines were formed in the photocurable PVA‐SbQ films, and the formation of PVA–polyiodine complexes was enhanced by boric acid treatment. It was found that the SbQ‐ratio of PVA‐SbQ affects the formation of PVA–polyiodine complexes. The photocrosslinking by the dimerization of SbQ groups helps to form the PVA–I₅⁻ complex during the boric acid treatment. Based on this effect, we demonstrated a unique recording method by the PVA–polyiodine complex formation. The PVA‐SbQ film cured by the irradiation of the liner polarized light showed that dichroism of the PVA–polyiodine complexes formed after iodination. Copyright © 2015 John Wiley & Sons, Ltd.