Diphosgene

Diphosgene (Trichloromethyl chloroformate, ClCO₂CCl₃) is a chemical originally developed for chemical warfare, a few months after the first use of phosgene. At room temperature it is a stable colourless liquid. It decomposes to phosgene and chloroform at 300 degrees C.

Diphosgene can be used in the synthesis of isocyanids.

Diphosgene vapour is a lung irritant and has an LC₁₀₀ for rabbits at a concentration of 0.9 mg/l of air.

Diphosgene was used as a poisonous gas in artillery shells by Germany during World War I. The first recorded battlefield use was in May of 1916. Diphosgene was developed because the vapours could destroy the filters in gas masks in use at the time.

The chemical structure is:

      O   Cl
     / \\ /
O = C   C - Cl
    |   |
    Cl  Cl

External links

• medical care guide.
• NATO guide, includes treatment advice
• material safety data sheet (PDF, for phosgene and diphosgene treated as one).