Iodine was discovered by Bernard Courtois in 1811. Charles Bernard Desormes (1777–1862) and Nicolas Clément (1779–1841), to continue research. He also gave some of the substance to Joseph Louis Gay-Lussac (1778–1850), a well-known chemist at that time, and to physicist André-Marie Ampère (1775–1836). On 29 November 1813, Dersormes and Clément made public Courtois’s discovery. On December 6, Gay-Lussac announced that the new substance was either an element or a compound of oxygen. Ampère had given some of his sample to Humphry Davy (1778–1829). Davy did some experiments on the substance and noted its similarity to chlorine. Davy sent a letter dated December 10 to the Royal Society of London stating that he had identified a new element. element.

Reported in EPA TSCA Inventory.

OSHA PEL: CL 0.1 ppm
ACGIH TLV: CL 0.1 ppm
DFG MAK: 0.1 ppm (1.1 mg/m³)

For occupational chemical analysis use OSHA: #ID-177 or NIOSH: Iodine, 6005.

Iodine (CAS NO.7553-56-2), its Synonyms are Actomar; Diiodine; Eranol; Ethanolic solution of iodine; Iodine Tincture. It is violet-black crystals with a metallic luster and a sharp odor. It forms compounds with most elements, but is less reactive than the other halogens, which displace it from iodides. Iodine exhibits some metallic-like properties. It dissolves readily in chloroform, carbon tetrachloride, or carbon disulphide to form beautiful purple solutions. It is only slightly soluble in water. Iodine compounds are important in organic chemistry and very useful in medicine and photography.

Physical properties about Iodine are: 
(1)ACD/LogP: 2.064; (2)ACD/LogD (pH 5.5): 2.06; (3)ACD/LogD (pH 7.4): 2.06; (4)ACD/BCF (pH 5.5): 21.82; (5)ACD/BCF (pH 7.4): 21.82; (6)Index of Refraction: 1.788 ; (7)Molar Refractivity: 27.988 cm³; (8)Molar Volume: 66.188 cm³; (9)Polarizability: 11.095 10-24cm³; (10)Surface Tension: 54.8499984741211 dyne/cm; (11)Density: 3.835 g/cm³ ; (12)Enthalpy of Vaporization: 41.57 kJ/mol; (13)Boiling Point: 184.35 °C at 760 mmHg; (14)Vapour Pressure: 0.490000009536743 mmHg at 25°C

Preparation of Iodine: 
Iodine can be produced from iodates:
IO₃- + 3SO₂ + 3H₂O → I- + 3SO4₂- + 6H-
IO₃- + I- + 6H+ → 3I₂ + 3H₂O
Iodine can also be produced from brine. This process consists of cleaning the solution (of clays and other materials), adding sulfuric acid to a pH <2.5 followed by treatment with gaseous chlorine:
2I- + Cl₂ → I₂ + 2Cl-
after which the Iodine is recovered by a countercurrent air blow out step. process.

Uses of Iodine:
Iodine (CAS NO.7553-56-2) is used for the manufacture of organic compounds, for the manufacture of potassium iodide and sodium iodide, and for the manufacture of other inorganic compounds. Iodine is used as a catalyst in the chlorination of organic compounds and in analytical chemistry for determination of the iodine numbers of oils. Iodine for medicinal, photographic, and pharmaceutical purposes is usually in the form of alkali iodides, prepared through the agency of ferrous iodide. It is also used for the manufacture of dyes and as a germicide. Simple iodine derivatives of hydrocarbons, such as iodoform (CHI₃), have an antiseptic action. Organic compounds containing iodine have been used as rubber emulsifiers, chemical antioxidants, and dyes and pigments.

Safety information of Iodine:
When you are using this chemical, please be cautious about it as the following:
1. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice;
2. Avoid release to the environment. Refer to special instructions safety data sheet;
3. Avoid contact with eyes;
4. Do not breathe gas/fumes/vapor/spray (appropriate wording to be specified by the manufacturer);

You can still convert the following datas into molecular structure:
(1)InChI=1S/I2/c1-2;
(2)InChIKey=PNDPGZBMCMUPRI-UHFFFAOYSA-N;
(3)SmilesII

The toxicity data of Iodine is as follows: