Dichlorobenzenes

Dichlorobenzenes are a group of chlorinated benzenes in which two hydrogen atoms on the benzene ring are replaced by chlorine atoms. The three constitutional isomers are 1,2-dichlorobenzene (ortho), 1,3-dichlorobenzene (meta), and 1,4-dichlorobenzene (para). They are colorless to pale-yellow solids or liquids at room temperature and are relatively nonpolar. They have low solubility in water and are more soluble in many organic solvents.

Industrial production typically involves chlorination of benzene or monochlorobenzene under controlled conditions, followed by distillation to separate the isomers. The distribution of isomers depends on temperature, catalysts, and chlorine availability. Dichlorobenzenes are often obtained as mixtures and then separated into individual isomers.

In use, dichlorobenzenes are commodity chemicals and precursors for a variety of products. They serve as intermediates in the manufacture of dyes, pigments, agrochemicals, and pharmaceuticals. Among the isomers, p-dichlorobenzene is widely used as a deodorizer and moth repellent; o- and m-dichlorobenzene find use as solvents and chemical intermediates in various industrial processes.

Safety and environment: Dichlorobenzenes can be hazardous; exposure may irritate skin, eyes, and the respiratory system, and some compounds are toxic to aquatic life. They are relatively persistent in the environment and require appropriate handling, ventilation, and disposal in accordance with regulations.