C2H2I2

C2H2I2 refers to a chemical compound with the molecular formula indicating two carbon atoms, two hydrogen atoms, and two iodine atoms. This formula can represent several different structural isomers, meaning compounds with the same atoms but arranged in different ways. The most common and well-understood isomer is diiodoacetylene.

Diiodoacetylene is a linear molecule with the structure I-C≡C-I. It is a derivative of acetylene (ethyne), where the two hydrogen atoms have been replaced by iodine atoms. This compound is a solid at room temperature and is known for its reactivity, particularly due to the presence of the carbon-carbon triple bond and the relatively weak carbon-iodine bonds. Diiodoacetylene can undergo various addition reactions typical of alkynes, and the iodine atoms can be substituted in certain chemical transformations. Its synthesis often involves reactions with iodine sources on acetylene precursors. Due to its reactivity and potential instability, it is handled with care in laboratory settings. Other less common or hypothetical isomers with the formula C2H2I2 might include cis- and trans-1,2-diiodoethylene, where the iodine atoms are attached to adjacent carbon atoms that are part of a double bond, but these are less frequently discussed than diiodoacetylene.