Interaction of thioamides, selenoamides, and amides with diiodine.

We review the results of our work on the iodine interaction with thioamides, selenoamides, and amides. Complexes with (i) "spoke" or "extended spoke" structures, D . I(2) and D . I(2) . I(2), respectively, (D is the ligand donor) (ii) iodonium salts of {[D(2) - I](+)[I(n)](-)} (n = 3, 7) and {[D(2) - I](+)[FeCl(4)](-)} formulae and (iii) disulfides of the categories (a) [D - D], (b) {[D - DH](+)[I(3)](-)} have been isolated and characterized. A compound of formula {[D(2) - I](+)[I(3)](-)[D . I(2)]} containing both types of complexes (i) and (ii) was also isolated. The interaction of diiodine with selenium analogs of the antithyroid drug 6-n-propyl-2-thiouracil (PTU), of formulae RSeU (6-alkyl-2-Selenouracil) results in the formation of complexes with formulae [(RSeU)I(2)]. All these results are correlated with the mechanism of action of antithyroid drugs. Finally, we review here our work on the diiodine interaction with the amides (LO).