Laser-Induced Addition Reactions of Iodine with Acetylene

Laser-induced addition reactions of iodine with acetylene at 5145 and 4880 Å excitation wavelengths are studied, while trans-1,2-diiodoethylene is identified as the exclusive reaction product. A sequential addition reaction mechanism initiated by iodine atoms from the direct photodissociation process or collisional induced dissociation can be inferred.