paradiiodobenzene

p-Diiodobenzene, also known as 1,4-diiodobenzene, is an organoiodine compound with the chemical formula C6H4I2. It is a white crystalline solid at room temperature. It is one of three possible isomers of diiodobenzene, the other two being o-diiodobenzene (1,2-diiodobenzene) and m-diiodobenzene (1,3-diiodobenzene). In p-diiodobenzene, the two iodine atoms are located at opposite positions on the benzene ring.

This compound is typically synthesized through the iodination of benzene or by the Sandmeyer reaction involving p-phenylenediamine. It is relatively stable but can decompose upon prolonged exposure to light or heat. p-Diiodobenzene is sparingly soluble in water but soluble in many organic solvents such as ethanol, ether, and benzene.

p-Diiodobenzene finds applications as a building block in organic synthesis. It is commonly used in cross-coupling reactions, such as Suzuki, Sonogashira, and Heck couplings, to form more complex organic molecules. These reactions are important in the synthesis of pharmaceuticals, agrochemicals, and materials science. Its symmetrical structure and the presence of two reactive iodine atoms make it a versatile precursor for creating molecules with specific architectures.