Iodosobenzene

Iodosobenzene or iodosylbenzene is an organoiodine compound with the empirical formula C₆H₅IO. This colourless solid compound is used as an oxo transfer reagent in research laboratories examining organic and coordination chemistry.

Iodosobenzene

Names
Preferred IUPAC name Iodosylbenzene[1]
Other names Iodosobenzene
Identifiers
CAS Number	536-80-1 Y
3D model (JSmol)	Interactive image
ChemSpider	83171 Y
ECHA InfoCard	100.007.864
EC Number	208-648-8
PubChem CID	92125
UNII	TWW7V7Q50P Y
CompTox Dashboard (EPA)	DTXSID1060213
InChI InChI=1S/C6H5IO/c8-7-6-4-2-1-3-5-6/h1-5H Y Key: JYJVVHFRSFVEJM-UHFFFAOYSA-N Y InChI=1/C6H5IO/c8-7-6-4-2-1-3-5-6/h1-5H Key: JYJVVHFRSFVEJM-UHFFFAOYAR
SMILES c1ccc(cc1)I=O
Properties
Chemical formula	C6H5IO
Molar mass	220.01 g/mol
Appearance	colourless solid
Density	1.229 g cm−3
Melting point	210 ˚C
Solubility in water	poor
Hazards
GHS labelling:[2]
Pictograms
Signal word	Danger
Hazard statements	H228, H271, H315, H319, H335
Precautionary statements	P210, P220, P240, P241, P261, P264, P264+P265, P271, P280, P283, P302+P352, P304+P340, P305+P351+P338, P306+P360, P319, P321, P332+P317, P337+P317, P362+P364, P370+P378, P371+P380+P375, P403+P233, P405, P420, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Preparation and structure

Iodosobenzene is prepared from iodobenzene.^[3] It is prepared by first oxidizing iodobenzene by peracetic acid. Hydrolysis of resulting diacetate affords "PhIO":^[4]

C₆H₅I + CH₃CO₃H + CH₃CO₂H → C₆H₅I(O₂CCH₃)₂ + H₂O

C₆H₅I(O₂CCH₃)₂ + H₂O → C₆H₅IO + 2 CH₃CO₂H

The structure of iodosobenzene has been verified by crystallographically.^[5] Related derivatives are also oligomeric.^[6] Its low solubility in most solvents and vibrational spectroscopy indicate that it is not molecular, but is polymeric, consisting of –I–O–I–O– chains.^[7] The related diacetate, C₆H₅I(O₂CCH₃)₂, illustrates the ability of iodine(III) to adopt a T-shaped geometry without multiple bonds.^[8] Theoretical studies show that the bonding between the iodine and oxygen atoms in iodosobenzene represents a single dative I-O sigma bond, confirming the absence of the double I=O bond.^[9]

A monomeric derivative iodosylbenzene is known in the form of 2-(tert-butylsulfonyl)iodosylbenzene, a yellow solid. C-I-O angle is 94.78°, C-I and I-O distances are 2.128 and 1.848 Å.^[10]

Structure of 2-(tert-butylsulfonyl)iodosylbenzene.

Applications

Iodosobenzene has no commercial uses, but in the laboratory it is employed as an "oxo-transfer reagent." It epoxidizes certain alkenes and converts some metal complexes into the corresponding oxo derivatives. Although it is an oxidant, it is also mildly nucleophilic. These oxo-transfer reactions operate by the intermediacy of adducts PhI=O→M, which release PhI.^[11]

A mixture of iodosobenzene and sodium azide in acetic acid converts alkenes to vicinal diazides:.^[12][13]

R₂C=CR₂ + 2 NaN₃ + PhIO + 2 AcOH → (N₃)R₂C−CR₂(N₃) + PhI + 2 AcONa + H₂O

Safety

This compound is explosive and should not be heated under vacuum.

See also

• Dess-Martin reagent