Search results
Results from the WOW.Com Content Network
Iodine is the fourth halogen, being a member of group 17 in the periodic table, below fluorine, chlorine, and bromine; since astatine and tennessine are radioactive, iodine is the heaviest stable halogen. Iodine has an electron configuration of [Kr]5s 2 4d 10 5p 5, with the seven electrons in the fifth and outermost shell being its valence ...
[1] [2] [3] Introduced by Gilbert N. Lewis in his 1916 article The Atom and the Molecule, a Lewis structure can be drawn for any covalently bonded molecule, as well as coordination compounds. [4] Lewis structures extend the concept of the electron dot diagram by adding lines between atoms to represent shared pairs in a chemical bond.
Thus when iodine is ligated to an organic residue and two Lewis acids, it is in the +3 oxidation state and the corresponding compound is a λ 3 ‑iodane. A compound with iodine(V) would be a λ 5 ‑iodane, and a hypothetical iodine(VII)‑containing compound would be a λ 7 ‑iodane.
The role of iodine in mammary tissue is related to fetal and neonatal development, but its role in the other tissues is not well known. [8] It has been shown to act as an antioxidant [8] and antiproliferant [9] in various tissues that can uptake iodine. Molecular iodine (I 2) has been shown to have a suppressive effect on benign and cancerous ...
Iodine trichloride, which exists in the solid state as the planar dimer I 2 Cl 6, is a bright yellow solid, synthesised by reacting iodine with liquid chlorine at −80 °C; caution is necessary during purification because it easily dissociates to iodine monochloride and chlorine and hence can act as a strong chlorinating agent.
The most common Lewis bases are anions. The strength of Lewis basicity correlates with the pK a of the parent acid: acids with high pK a 's give good Lewis bases. As usual, a weaker acid has a stronger conjugate base. Examples of Lewis bases based on the general definition of electron pair donor include: simple anions, such as H − and F −
Of the halides, iodide usually is the best leaving group. Because of the weakness of the C–I bond, samples of organoiodine compounds are often yellow due to an impurity of I 2. A noteworthy aspect of organoiodine compounds is their high density, which arises from the high atomic weight of iodine.
The Wijs solution, iodine monochloride dissolved in acetic acid, is used to determine the iodine value of a substance. It can also be used to prepare iodates, by reaction with a chlorate. Chlorine is released as a byproduct. Iodine monochloride is a Lewis acid that forms 1:1 adducts with Lewis bases such as dimethylacetamide and benzene.