Chemical Properties
Fuming liquid.Attacks glass.
Uses
Mild fluorinating agent.
General Description
A toxic colorless fuming liquid (m.p. 9° C). Decomposed by water to iodine and hydrofluoric acid. Contact with organic materials may cause their ignition. Corrosive to metals and tissue. Prolonged exposure of the container to fire or heat may result in their violent rupturing and rocketing. Prolonged exposure to low concentrations or short term exposure to high concentrations may result in adverse health effects.
Reactivity Profile
A powerful oxidizer. Attack glass. Reacts violently with water or strong bases (potassium hydroxide, sodium hydroxide). IODINE PENTAFLUORIDE(7783-66-6) chars and usually ignites organic matter. Contact with boron, silicon, red phosphorus, sulfur, arsenic, antimony, bismuth, molybdenum and tungsten causes incandescence. Contact with potassium or sodium leads to explosions. Causes aluminum (foil, powder) to ignite. Explosive reactions with tetraiodoethylene, diethylaminotrimethylsilane. Violent reactions wilh benzene, dimethyl sulfoxide, tetraiodoethylene [Bretherick, 5th ed., 1995, p. 1434]. IF5 reacts explosively with diethylaminotrimethylsilane even at low temperature. (Oates, G. et al., J. Chem. Soc., Dalton Trans., 1974, 1383).
Air & Water Reactions
Fumes in air. Reaction with water or water-containing materials is violent, [Mellor 2, Supp. 1:176, 1956].
Hazard
Dangerous fire risk, reacts violently with
water. Toxic by ingestion and inhalation, corrosive
to skin and mucous membranes.
Health Hazard
TOXIC; inhalation or contact with vapor, substance, or decomposition products may cause severe injury or death. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may cause pollution.
Fire Hazard
May ignite combustibles (wood, paper, oil, clothing, etc.). React vigorously and/or explosively with water. Produce toxic and/or corrosive substances on contact with water. Flammable/toxic gases may accumulate in tanks and hopper cars. Some may produce flammable hydrogen gas upon contact with metals. Containers may explode when heated. Runoff may create fire or explosion hazard.
Physical properties
Black crystalline solid; exists in two modifications: stable black needlesknown as alpha form that produces ruby-red color in transmitted light, and alabile, metastable beta modification consisting of black platelets which appearbrownish-red in transmitted light; density of alpha form 3.86 g/cm3at 0°C;density of beta form 3.66 g/cm3at 0°C; alpha form melts at 27.3°C, vapor pressure being 28 torr at 25°C; beta form melts at 13.9°C; liquid iodine monochloride has bromine-like reddishbrown color; liquid density 3.10 g/mL at 29°C;viscosity 1.21 centipoise at 35°C; decomposes around 100°C; supercools belowits melting point; polar solvent; as a liquid it dissolves iodine, ammoniumchloride and alkali metal chlorides; liquid ICl also miscible with carbon tetrachloride, acetic acid and bromine; the solid crystals dissolve in ethanol, ether,acetic acid and carbon disulfide; solid ICl also dissolves in conc. HCl butdecomposes in water or dilute HCl.
Preparation
Iodine monochloride is prepared by the action of liquid or dry chlorine on astoichiometric quantity of solid iodine. Aqueous solutions of ICl are preparedby passing chlorine gas into a suspension of iodine in moderately stronghydrochloric acid:
5I2 + 4HCl + 3Cl2 → 10ICl + 2H2
Alternatively, iodine monochloride may be made by oxidation of iodine withiodic acid in strong hydrochloric acid solution:
2I2 + HIO3 + 2HCl → 2ICl + 3HIO
Purification Methods
Rogers et al. [J Am Chem Soc 76 4843 1954] removed dissolved iodine from IF5 by agitating with a mixture of dry air and ClF3 in a Fluorothene beaker using a magnetic stirrer. The mixture is transferred to a still, and the more volatile impurities are pumped off as the pressure is reduced below 40mm. The still is gradually heated (kept at 40mm) to remove the ClF3 before IF5 distilled. Stevens [J Org Chem 26 3451 1961] pumped IF5 under vacuum from its cylinder, trapping it at -78o, then allowing it to melt in a stream of dry N2. HARMFUL VAPOURS. [Kwasnik in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I pp 159-160 1963.]
Flammability and Explosibility
Nonflammable
