Dichlorobenzene

Dichlorobenzenes are a family of chlorinated aromatic hydrocarbons with two chlorine substituents on a benzene ring. There are three structural isomers: ortho-dichlorobenzene (1,2-dichlorobenzene), meta-dichlorobenzene (1,3-dichlorobenzene), and para-dichlorobenzene (1,4-dichlorobenzene). They share a common molecular formula, C6H4Cl2, and similar chemical behavior as mildly polar, volatile organochlorines.

Physical properties vary by isomer. They are typically colorless to pale yellow solids or liquids with low water solubility and appreciable solubility in organic solvents. Boiling points are in the mid to high 170s °C range, and the compounds are relatively stable under ordinary conditions.

Production and use: Dichlorobenzenes are produced by chlorinating benzene or chlorobenzene in the presence of catalysts, yielding mixtures of isomers that are separated by distillation or crystallization. They serve as important industrial intermediates and solvents for dyes, resins, waxes, and rubber processing. Among the isomers, p-dichlorobenzene is widely used as a deodorizer and moth repellent in consumer products. The isomers are also used to make agrochemicals and other organic synthesis intermediates.

Safety and environmental: Dichlorobenzenes are moderately toxic and can cause irritation of the skin, eyes, and respiratory tract. Prolonged or repeated exposure may affect the liver and kidneys. They are persistent in the environment and can volatilize, requiring careful handling, ventilation, and compliance with regulatory limits. Disposal should follow hazardous waste guidelines.