Monochlorobenzene

Monochlorobenzene, also known as chlorobenzene, is an aromatic organic compound with the formula C6H5Cl. It is a colorless to pale yellow liquid at room temperature with a characteristic mild odor. Its boiling point is about 131°C, and its melting point is around −45°C. It has a density of approximately 1.11 g/cm3, a refractive index near 1.533, and is only sparingly soluble in water (roughly 0.3 g/L at 20°C), with higher solubility in most organic solvents.

Production and occurrence: Industrially, monochlorobenzene is produced by the chlorination of benzene in the presence of a catalyst. The process yields a mixture of chlorinated benzenes, including monochloro-, dichloro-, and other polychlorinated benzenes, which are separated and purified to obtain monochlorobenzene.

Applications: It is used as a solvent and as a chemical intermediate in the manufacture of dyes, pigments, resins, pharmaceuticals, and agrochemicals. It serves as a building block for various chlorinated aromatic compounds and can be employed in the synthesis of other phenyl derivatives.

Safety and handling: Monochlorobenzene is flammable and releases vapors that can form explosive mixtures with air. It is harmful if inhaled or absorbed through the skin and may irritate the eyes and respiratory tract. Handling requires adequate ventilation, avoidance of ignition sources, and use of appropriate protective equipment. It is toxic to aquatic life and should be contained and disposed of according to local regulations.

Storage and environmental aspects: Store in tightly closed containers in a cool, well‑ventilated area away from oxidizers. It is relatively persistent in the environment and can volatilize from water or soil, with potential ecological effects if released in large amounts.