Iodobenzene dichloride (PhICl₂) is a complex of

iodobenzene Iodobenzene is an organoiodine compound consisting of a benzene ring substituted with one iodine atom. It is useful as a synthetic intermediate in organic chemistry. It is a volatile colorless liquid, although aged samples appear yellowish. Pre ...

with

chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine i ...

. As a reagent for organic chemistry, it is used as an

oxidant An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxi ...

and chlorinating agent.

Chemical structure

Single-crystal X-ray crystallography has been used to determine its structure; as can be predicted by

VSEPR theory Valence shell electron pair repulsion (VSEPR) theory ( , ), is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. It is also named the Gillespie-Nyholm the ...

, it adopts a T-shaped geometry about the central iodine atom.

Preparation

Iodobenzene dichloride is not stable and is not commonly available commercially. It is prepared by passing chlorine gas through a solution of

in chloroform, from which it precipitates. The same reaction has been reported at pilot plant scale (20 kg) as well. :Ph-I + Cl₂ → PhICl₂ An alternate preparation involving the use of

generated ''in situ'' by the action of

sodium hypochlorite Sodium hypochlorite (commonly known in a dilute solution as bleach) is an inorganic chemical compound with the formula NaOCl (or NaClO), comprising a sodium cation () and a hypochlorite anion (or ). It may also be viewed as the sodium s ...

hydrochloric acid Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid Acid strength is the tendency of an acid, symbol ...

has also been described.

Reactions

Iodobenzene dichloride is hydrolyzed by basic solutions to give

iodosobenzene Iodosobenzene or iodosylbenzene is an organoiodine compound with the empirical formula . This colourless solid compound is used as an oxo transfer reagent in research laboratories examining organic and coordination chemistry. Preparation and st ...

(PhIO) and is oxidized by

to give

iodoxybenzene Periodinanes also known as λ5- iodanes are organoiodine compounds with iodine in the +5 oxidation state. These compounds are described as hypervalent because the iodine center has more than 8 valence electrons. Periodinane compounds The λ5-io ...

(PhIO₂). In organic synthesis, iodobenzene dichloride is used as a reagent for the selective chlorination of

alkene In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic, an ...

s and alkynes.

Chemical structure

Preparation

Reactions

References

Further reading