Sodium iodide dichloride, also known as sodium dichloroiodate(I), is an inorganic compound with the formula NaICl₂. It is a stable, crystalline solid that serves as a convenient source of the electrophilic chlorine species "Cl⁺". This compound is typically prepared by the reaction of sodium iodate with chlorine in an acidic medium or by combining sodium iodide with chlorine. Its primary application is as a versatile and selective chlorinating reagent in organic synthesis. It is particularly useful for the chlorination of aromatic compounds, alkenes, and activated methylene groups under mild conditions. The reagent offers advantages such as high regioselectivity and the ability to perform reactions in various solvents. Additionally, sodium iodide dichloride finds use in analytical chemistry as an oxidizing agent in iodometric titrations for the determination of reducing agents. As a solid, it is easier to handle than gaseous chlorine. It decomposes upon contact with water or moist air, releasing chlorine and iodine. Standard safety precautions for handling oxidizing agents and halogens should be observed, including the use of personal protective equipment and adequate ventilation.