33 (2: 1) a All reactions were carried out in the presence of an aqueous solution of sulfurous acid to remove the iodine formed, and the yields were calculated on the basis of polyhalomethane used. No isomerization of cis-2-butene was detected by vpc. polyiodomethane proceeds via two primary processes,(i) dissociation to form an iodine atom and a radical (reaction 1) and (ii) dissociation to form an iodine molecule and a methylene ...