Thionyl Chloride(redirected from Thionyl dichloride)
thionyl chloride[′thī·ən·əl ′klȯr‚īd]
(SOCl2), a colorless liquid that fumes upon exposure to air. Thionyl chloride is prepared commercially by the direct reaction of S, O2 and Cl2 at 180°–200°C (using activated carbon as a catalyst) or by the action of excess SO2 on CCl 4in the presence of AlCl3 at 150°C and pressure of about 4 meganewtons per sq m, or 40 kilograms-force per sq cm. It is used for the preparation of sulfochlorinated polymer derivatives, and also as a chlorinating agent—for example, in the manufacture of dyes and pharmaceuticals.
Thionyl chloride is toxic; it irritates the mucous membranes, causing severe burns.