Tetraiodoethylene (TIE), or diiodoform, is the periodinated analogue of ethylene with the chemical formula . It is a decomposition product of carbon tetraiodide and diiodoacetylene.[1] It is an odourless yellow crystalline solid that is soluble in benzene and chloroform, and insoluble in water.[2] It has been used as an antiseptic and a component in pesticide and fungicide formulations.[3] [4]
Tetraiodoethylene reacts with ethylamine to give ethylamine di-tetraiodoethylene, EtNH2.(C2I4)2,and ethylaminetetraiodoethylene.[5] Tetraiodoethylene and iodine pentafluoride yield iodopentafluoroethane.[6]
Tetraiodoethylene turns brown and emits a "characteristic" odour due to decomposition when exposed to light.
Tetraiodoethylene was discovered by Baeyer in 1885.[1] It was proposed as an antiseptic under the name Diiodoform, in 1893 by M. L. Maquenne and Taine. It was an alternative to iodoform[7] which has a strong and persistent odour that caused difficulties for physicians in private practices.[8]
Tetraiodoethylene can be made by the iodination of calcium carbide:[9]
Diiodoacetylene is a byproduct of the reaction which can later be iodinated to TIE.[9]
The action of aqueous solution of potassium hydroxide and iodine on barium carbide in chloroform or benzene can also give TIE.[7] Another synthesis involves mixing separate solutions of diiodoacetylene and iodine in carbon disulphide. Tetraiodoethylene would be left as a residue after carbon disulphide was evaporated.[7]