よう素(V)ペンタフルオリド

解説フッ化ヨウ素【Ⅰ】五フッ化ヨウ素(iodine pentafluoride)：IF5(221.90)．フッ化ヨウ素(Ⅴ)ともいう．固体のヨウ素と気体のフッ素との反応や，AgFと I2 との反応，HIと F2 との反応などにより得られる．気体分子は，5個のF原子が正方すい型に配置し，I原子は底面中心に位置する．I-F約1.87 Å(底面)，1.84 Å(頂点)．室温では無色の液体．融点9.43 ℃，沸点101 ℃．反応性が大きく，多くの金属・非金属とただちに反応してフッ化物をつくる．水とはげしく反応して，I2O5とHFになる．ガラスを侵す(とくに高温ではいちじるしい)．多くの有機化合物とはげしく反応する．フッ素化剤に用いられる．

使用Iodine pentafluoride is a fluorinating agent and strong oxidant, which plays an important role in organic synthesis. It can be used to prepare pentafluoroiodoethane:5 CF2=CF2 + IF5 + 2 I2 → 5 C2F5IIn addition, iodine pentafluoride can also react with isothiocyanato to generate fluorinated hydrocarbon derivatives, and to synthesize other fluorine-containing compounds.Iodine pentafluoride (IF5) is rarely used to fluoride common organic compounds due to the difficulty in controlling their reactivity.

一般的な説明Iodine pentafluoride appears as 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.

製造方法Iodine pentafluoride(IF5) is produced by the action of elemental fluorine on iodine which has a low melting point. The reaction is performed either in solvent or heating iodine to maintain its liquid state. In a commercial preparation about one percent iodine is dissolved in IF5 and brought into fluorination chamber where iodine reacts with fluorine and produces more IF5 which is returned to the receiving vessel. Only a small portion of IF5 is withdrawn from the receiving vessel as product, while the major portion of IF5 is used for dissolving more iodine. This process goes on and on until all iodine is converted into IF5.In another industrial process, iodine is heated above its melting point (113℃) and reacted with elemental fluorine under three atmosphere of pressure. A precaution is taken not to heat iodine above 150℃ to avoid the formation of another product, IF7. Fluorine is added continuously until all iodine has reacted and converted to IF5.