Iodobenzene dichloride (PhICl₂) is a complex of

iodobenzene Iodobenzene is an aryl iodide and the simplest of the iodobenzenes, consisting of a benzene ring substituted with one iodine atom. Its chemical formula is . It is useful as a synthetic intermediate in organic chemistry. It is a volatile colorles ...

with

chlorine Chlorine is a chemical element; it has Symbol (chemistry), 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 ...

. As a

reagent In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a ...

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 "Electron acceptor, accepts"/"receives" an electron from a (called the , , or ''electr ...

and chlorinating agent.

Chemical structure

Single-crystal X-ray crystallography X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract in specific directions. By measuring the angles and ...

has been used to determine its structure; as can be predicted by

VSEPR theory Valence shell electron pair repulsion (VSEPR) theory ( , ) is a conceptual model, 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 Gill ...

, 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

chloroform Chloroform, or trichloromethane (often abbreviated as TCM), is an organochloride with the formula and a common solvent. It is a volatile, colorless, sweet-smelling, dense liquid produced on a large scale as a precursor to refrigerants and po ...

, 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 is an alkaline inorganic chemical compound with the formula (also written as NaClO). It is commonly known in a dilute aqueous solution as bleach or chlorine bleach. It is the sodium salt of hypochlorous acid, consisting of ...

hydrochloric acid Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is ...

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 stru ...

(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-iodane ...

(PhIO₂). In

organic synthesis Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the gen ...

, iodobenzene dichloride is used as a reagent for the selective chlorination of

alkene In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or at the terminal position. Terminal alkenes are also known as Alpha-olefin, α-olefins. The Internationa ...

s. and

alkyne \ce \ce Acetylene \ce \ce \ce Propyne \ce \ce \ce \ce 1-Butyne In organic chemistry, an alkyne is an unsaturated hydrocarbon containing at least one carbon—carbon triple bond. The simplest acyclic alkynes with only one triple bond and n ...

Chemical structure

Preparation

Reactions

References

Further reading