Chemistry:Iodobenzene dichloride

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Iodobenzene dichloride[1]
PhICl2-2D-skeletal.png
Iodobenzene-dichloride-from-xtal-3D-sf.png
Names
Preferred IUPAC name
Dichloro(phenyl)-λ3-iodane
Other names
Iodosobenzene dichloride; Phenyliodine(III) dichloride; Phenyliodo dichloride; Phenyliodoso chloride; Phenylchloroiodonium chloride; Dichloroiodobenzene; Iododichlorobenzene
Identifiers
3D model (JSmol)
Abbreviations IBD
ChemSpider
UNII
Properties
C6H5Cl2I
Molar mass 274.91 g·mol−1
Appearance Yellow solid
Density 2.2 g/cm3
Melting point 115 to 120 °C (239 to 248 °F; 388 to 393 K) (decomposes)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

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.[2]

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

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.[5]

Reactions

Iodobenzene dichloride is hydrolyzed by basic solutions to give iodosobenzene (PhIO)[6] and is oxidized by sodium hypochlorite to give iodoxybenzene (PhIO2).[7]

In organic synthesis, iodobenzene dichloride is used as a reagent for the selective chlorination of alkenes.[1] and alkynes.[8]

References

  1. 1.0 1.1 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 Crystallogr. 6: 88–92. doi:10.1107/S0365110X53000193. 
  3. H. J. Lucas and E. R. Kennedy (1942). "Iodobenzene dichloride". Organic Syntheses 22: 69. doi:10.15227/orgsyn.022.0069. 
  4. 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. 
  5. 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. 
  6. H. J. Lucas, E. R. Kennedy, and M. W. Formo (1942). "Iodosobenzene". Organic Syntheses 22: 70. doi:10.15227/orgsyn.022.0070. 
  7. M. W. Formo, John R. Johnson (1942). "Iodoxybenzene: B. Hypochlorite oxidation of iodobenzene dichloride". Organic Syntheses 22: 72. doi:10.15227/orgsyn.022.0072. 
  8. 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.