Iodobenzene dichloride explained

Iodobenzene dichloride (PhICl₂) is a complex of iodobenzene with chlorine. As a reagent for organic chemistry, it is used as an oxidant and chlorinating agent.

Chemical structure

Single-crystal X-ray crystallography has been used to determine its structure; as can be predicted by VSEPR theory, it adopts a T-shaped geometry about the central iodine atom.^[1]

Preparation

Iodobenzene dichloride is not stable and is not commonly available commercially. It is prepared by passing chlorine gas through a solution of iodobenzene in chloroform, from which it precipitates. The same reaction has been reported at pilot plant scale (20 kg) as well.^[2]

Ph-I + Cl₂ → PhICl₂

An alternate preparation involving the use of chlorine generated in situ by the action of sodium hypochlorite on hydrochloric acid has also been described.^[3]

Reactions

Iodobenzene dichloride is hydrolyzed by basic solutions to give iodosobenzene (PhIO) and is oxidized by sodium hypochlorite to give iodoxybenzene (PhIO₂).

In organic synthesis, iodobenzene dichloride is used as a reagent for the selective chlorination of alkenes. and alkynes.^[4]

Further reading

• 10.1021/jo01280a047 . 1967 . Tanner . Dennis D . Van Bostelen . P. B. . . 32 . 1517–1521 . Free-radical chlorination reactions of iodobenzene dichloride . 5.

Notes and References

1. Acta Crystallogr.. 1953 . 6 . 88–92 . 10.1107/S0365110X53000193 . The crystal structure of benzene iododichloride . E. M. Archer and T. G. van Schalkwy. free .
2. 10.1021/op980024e . Large-Scale Preparation of Iodobenzene Dichloride and Efficient Monochlorination of 4-Aminoacetophenone . 1998 . Zanka . Atsuhiko . Takeuchi . Hiroki . Kubota . Ariyoshi . . 2 . 270 . 4.
3. 10.1055/s-2007-965889 . . Iodobenzene Dichloride as a Stoichiometric Oxidant for the Conversion of Alcohols into Carbonyl Compounds; Two Facile Methods for Its Preparation . 2007 . Zhao . Xue-Fei . Zhang . Chi . 2007 . 551 . 4.
4. Michael E. Jung and Michael H. Parker . Synthesis of Several Naturally Occurring Polyhalogenated Monoterpenes of the Halomon Class . . 1997 . 62 . 21 . 7094–7095 . 10.1021/jo971371 . 11671809.