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Published in Joseph C. Salamone, Polymeric Materials Encyclopedia, 2020
The iodine–polymer interactions have been studied extensively. Of these studies, the interaction with starch (amylose) and poly(vinyl alcohol) (PVA) to form bluecolored complexes are the most well known.1 With regard to amylose–iodine, the formation of a polyiodide complex inside the helical chain of amylose was first proposed by Freudenberg in 1939.2 This inclusion complex was substantiated by Rundle and Baldwin in 1944.3 A similar coloration mechanism was also proposed for the blue-colored aqueous solution of PVA-iodine by such pioneer researchers as Zwick and Tebelev.4,5 Zwick thought that the polyiodide ions may be formed in the host of helical PVA molecules, whereas Tebelev insisted that it is formed in the voids of the molecular aggregates of PVA.
What is iodine?
Published in Tatsuo Kaiho, Iodine Made Simple, 2017
Iodine is highly soluble in organic solvents. Depending on the characteristics of the solvent, solutions of varying color such as purple, red, and brown can be created. For example, chloroform and hexane solutions are purple, benzene, toluene, xylene solutions are red, and methanol, ethanol, and acetic acid solutions are brown. On the other hand, iodine does not dissolve well in water. However, in sodium iodide or potassium iodide solutions, the reaction shown in the bottom diagram occurs, producing polyiodide ion (I3−, I5−, etc.), which becomes easily soluble.
Synthesis, characterization, and crystal structures of iodides and polyiodides of scandium complexes with urea and acetamide
Published in Journal of Coordination Chemistry, 2019
Elena V. Savinkina, Denis V. Golubev, Mikhail S. Grigoriev
It could be assumed that scandium is able to form urea and acetamide complexes with iodide or polyiodide counterions. The purpose of the work was to synthesize scandium urea and acetamide complex iodides and polyiodides and to compare their structures to the structures of the corresponding complexes of transition and rare-earth metals.