Iodobenzene dichloride

Iodobenzene dichloride[1]
IUPAC name (Dichloro-λ3-iodanyl)benzene
Other names Iodosobenzene dichloride; Phenyliodine(III) dichloride; Phenyliodo dichloride; Phenyliodoso chloride; Phenylchloroiodonium chloride; Dichloroiodobenzene; Iododichlorobenzene
Identifiers
Abbreviations	IBD
CAS number	932-72-9 Y
Jmol-3D images	Image 1
SMILES ClI(Cl)C1=CC=CC=C1
Properties
Molecular formula	C6H5Cl2I
Molar mass	274.91 g mol−1
Appearance	Yellow solid
Density	2.2 g/cm3
Melting point	115–120 °C (dec.)
Y dichloride (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Iodobenzene dichloride (PhICl₂) is a complex of iodobenzene with chlorine. It is used as an oxidant.

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.^[2][3]

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.^[4] The same reaction has been reported at pilot plant scale (20 kg) as well.^[5]

PhI + 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.^[6]

Reactions

Iodobenzene dichloride is hydrolyzed by basic solutions to give iodosobenzene (PhIO),^[7] and is oxidized by sodium hypochlorite to give iodoxybenzene (PhIO₂).^[8]

In organic synthesis, iodobenzene dichloride is used as a reagent for the selective chlorination of alkenes^[1] and alkynes.^[9]

References

1. ^ ^{a b} Phenyliodine(III) Dichloride, David W. Knight and Glen A. Russell, in Encyclopedia of Reagents for Organic Synthesis, 2001, John Wiley & Sons, Ltd doi:10.1002/047084289X.rp071
2. ^ E. M. Archer and T. G. van Schalkwy (1953). "The crystal structure of benzene iododichloride". Acta Cryst. 6: 88–92. doi:10.1107/S0365110X53000193. 
3. ^ J. V. Carey, P. A. Chaloner, P. B. Hitchcock, T. Neugebauer, K. R. Seddon (1996). J. Chem. Res. 358: 2031–. 
4. ^ H. J. Lucas and E. R. Kennedy, "Iodobenzene dichloride", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv3p0482 ; Coll. Vol. 3: 482 
5. ^ Zanka, Atsuhiko; Takeuchi, Hiroki; Kubota, Ariyoshi (1998). "Large-Scale Preparation of Iodobenzene Dichloride and Efficient Monochlorination of 4-Aminoacetophenone". Organic Process Research & Development 2 (4): 270. doi:10.1021/op980024e. 
6. ^ Zhao, Xue-Fei; Zhang, Chi (2007). "Iodobenzene Dichloride as a Stoichiometric Oxidant for the Conversion of Alcohols into Carbonyl Compounds; Two Facile Methods for Its Preparation". Synthesis 2007 (4): 551. doi:10.1055/s-2007-965889. 
7. ^ H. J. Lucas, E. R. Kennedy, and M. W. Formo (1955), "Iodosobenzene", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv3p0483 ; Coll. Vol. 3: 483 
8. ^ M. W. Formo and John R. Johnson (1955), "Iodoxybenzene: B. Hypochlorite oxidation of iodobenzene dichloride", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv3p0485 ; Coll. Vol. 3: 485 
9. ^ Michael E. Jung and Michael H. Parker (1997). "Synthesis of Several Naturally Occurring Polyhalogenated Monoterpenes of the Halomon Class". Journal of Organic Chemistry 62 (21): 7094–7095. doi:10.1021/jo971371. PMID 11671809. 

Further reading

• Tanner, Dennis D; Van Bostelen, P. B. (1967). "Free-radical chlorination reactions of iodobenzene dichloride". Journal of Organic Chemistry 32 (5): 1517–1521. doi:10.1021/jo01280a047.