C6H5I

C6H5I, commonly called iodobenzene, is an organoiodine compound in which a single iodine substituent is attached to a phenyl ring. It has the formula C6H5I and a molar mass of about 204.0 g/mol. It is typically a colorless to pale yellow liquid at room temperature with a distinctive odor. It is less polar than benzene and is only sparingly soluble in water, but dissolves in many organic solvents. It is relatively reactive in carbon–iodine bond chemistry because aryl iodides generally undergo oxidative addition more readily than chlorides or bromides.

Preparation: Iodobenzene is commonly prepared by electrophilic iodination of benzene in the presence of a Lewis acid catalyst, such as ferric chloride or iodine/oxidant systems. It can also be accessed via iodination strategies starting from substituted benzenes or through conversion of anilines via diazonium intermediates (Sandmeyer-type routes).

Applications: It serves as an aryl iodide building block in organic synthesis. In cross-coupling reactions, iodobenzene participates in Suzuki–Miyaura, Negishi, and Sonogashira couplings to form biaryl and aryl–alkynyl products. It can also be converted to other aryl derivatives via Grignard or organolithium routes.

Safety: Iodobenzene is toxic and should be handled in a well-ventilated area with appropriate protective equipment. It is a hazardous irritant and may be harmful if swallowed or inhaled. It is flammable and should be stored away from heat and oxidizers.