Thionyl Chloride

(redirected from Thionyl dichloride)

thionyl chloride

[′thī·ən·əl ′klȯr‚īd]
(inorganic chemistry)
SOCl2 A toxic, yellowish to red liquid with a pungent aroma, soluble in benzene, decomposes in water and at 140°C; boils at 79°C; used as a chemical intermediate and catalyst. Also known as sulfur oxychloride; sulfurous oxychloride.

Thionyl Chloride


(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.

References in periodicals archive ?
Thionyl dichloride, N, N-dimethylacetamide and pyridine were procured from Mianyang Rongshen Chemical Reagents Company from Sichuan province in China.
N, N'-Bis(benzoyl) terephthalic acid dihydrazide was prepared as shown in Scheme 1: terephthalic acid, Thionyl dichloride of 50 mL in the presence of N, N-dimethylacetamide as catalyst was mixed, and the mixture was heated up to 80 degC, and held at 80 degC for 12 h with stirring.