Iodine monochloride

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Iodine monochloride
Iodine monochloride
Iodine monochloride
IUPAC name iodine(I) chloride
Other names iodine chloride
Identifiers
CAS number [7790-99-0]
SMILES ICl
Properties
Molecular formula ICl
Molar mass 162.35 g/mol
Appearance red to brown liquid
Density 3.10 g/cm3
Melting point

27°C (α-form)

Boiling point

97.4°C (370.6 K)

Solubility in water hydrolysis
Solubility in other solvents carbon disulfide
acetic acid
pyridine
Hazards
MSDS External MSDS
Main hazards corrosive
Related compounds
Related interhalogen compounds Chlorine monofluoride, bromine monochloride, iodine monobromide
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Iodine monochloride is the chemical compound with the formula ICl. It is a red-brown compound that melts near room temperature. Because of the difference in the electronegativity of iodine and chlorine, ICl is highly polar and behaves as a source of “I+.”

Preparation of iodine monochloride entails simply combining the halogens in a 1:1 molar ratio, according to the equation

I2 + Cl2 → 2 ICl

When chlorine gas is passed through iodine crystals, one observes the brown vapor of iodine monochloride. Dark brown iodine monochloride liquid is collected. Excess chlorine converts iodine monochloride into iodine trichloride in a reversible reaction:

ICl + Cl2 → ICl3

[edit] Polymorphs

ICl has two polymorphs; α-ICl which exists as black needles (red by transmitted light) with a melting point of 27.2 °C, and β-ICl which exists as black platelets (red-brown by transmitted light) with a melting point 13.9 °C.[1]

[edit] Uses

ICl is a useful reagent in organic synthesis.[1] It is used as a source of electrophilic iodine in the synthesis of certain aromatic iodides.[2] It also cleaves C-Si bonds.

ICl will also add to the double bond in alkenes to give chloro-iodo alkanes.

RCH=CHR’ + ICl → RCH(I)-CH(Cl)R’

When such reactions are conducted in the presence of sodium azide, the iodo-azide RCH(I)-CH(N3)R’ is obtained.[3]

[edit] References

  1. ^ a b Brisbois, R. G.; Wanke, R. A.; Stubbs, K. A.; Stick, R. V. “Iodine Monochloride” Encyclopedia of Reagents for Organic Synthesis, 2004 John Wiley & Sons. DOI: 10.1002/047084289X.ri014
  2. ^ Wallingford, V. H.; Krüger, P. A. (1943). "5-Iodo-anthranilic Acid". Org. Synth.; Coll. Vol. 2: 349. 
  3. ^ Padwa, A.; Blacklock, T.; Tremper, A.. "3-Phenyl-2H-Azirine-2-carboxaldehyde". Org. Synth.; Coll. Vol. 6: 893. 
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