Article · Wikipedia archive · Last revised Jul 18, 2026

Iodal

Iodal, or triiodoacetaldehyde, is a halogenated derivative of acetaldehyde with the chemical formula I3CCHO, it is analogous to chloral and bromal. It is described as a pale yellow liquid with a pungent odour by Leopold Gmelin. It is decomposed to iodoform by potash. Iodal was discovered and named in 1837.

Last revised
Jul 18, 2026
Read time
≈ 1 min
Length
238 w
Citations
4
Source
Wikipedia ↗
Iodal
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Names
IUPAC name
triiodoethanal
Other names
triiodoacetaldehyde
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 227-192-0
  • InChI=1S/C2HI3O/c3-2(4,5)1-6/h1H
    Key: SNWLPURUNKWTPY-UHFFFAOYSA-N
  • C(=O)C(I)(I)I
Properties
C2HI3O
Molar mass 421.742 g·mol−1
Appearance pale yellow liquid or solid
reacts to form a soluble hydrate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Iodal, or triiodoacetaldehyde, is a halogenated derivative of acetaldehyde with the chemical formula I3CCHO, it is analogous to chloral and bromal. It is described as a pale yellow liquid with a pungent odour by Leopold Gmelin. It is decomposed to iodoform by potash.1 Iodal was discovered and named in 1837.2

Iodal is synthesised from ethanol and iodine with concentrated nitric acid as the catalyst.1 Its hydrate was described as water-soluble, white silky crystals.3 Like most iodine compounds, Iodal is unstable under sunlight and gives off iodine over time.

References

References

  1. Iodal, Gmelin, L. (1855). Hand-book of Chemistry: Organic chemistry. UK: Cavendish Society. pages 186-187
  2. "Iodal" in Intelligence and Miscellaneous Articles, London and Edinburgh Philosophical Magazine and Journal of Science (1837)
  3. Iodal in Chemical Notices from Foreign Sources, The Chemical News: With which is Incorporated the Chemical Gazette: a Journal of Practical Chemistry in All Its Applications to Pharmacy, Arts, and Manufactures. (1862). UK: C. Mitchell and Company.