The reaction of thiourea and 1,3-dimethylthiourea towards organoiodines: oxidative bond formation and halogen bonding.

By varying the halogen-bond-donor mol­ecule, 11 new halogen-bonding co­crys­tals involving thio­urea or 1,3-di­methyl­thio­urea were obtained, namely, 1,3-di­­methyl­thio­urea–1,2-di­iodo-3,4,5,6-tetra­fluoro­ben­zene (1/1), C6F4I2·C3H8N2S, 1, thio­­urea–1,3-di­iodo-2,4,5,6-tetra­fluoro­ben­zene (1/1), C6F4I2·CH4N2S, 2, 1,3-di­methyl­thio­urea–1,3-di­iodo-2,4,5,6-tetra­fluoro­ben­zene (1/1), C6F4I2·C3H8N2S, 3, 1,3-di­methyl­thio­urea–1,3-di­iodo-2,4,5,6-tetra­fluoro­ben­zene–methanol (1/1/1), C6F4I2·C3H8N2S·CH4O, 4, 1,3-di­methyl­thio­urea–1,3-di­iodo-2,4,5,6-tetra­fluoro­ben­zene–ethanol (1/1/1), C6F4I2·C3H8N2S·C2H6O, 5, 1,3-di­methyl­thio­urea–1,4-di­iodo-2,3,5,6-tetra­fluoro­ben­zene (1/1), C6F4I2·C3H8N2S, 6, 1,3-di­methyl­thio­urea–1,3,5-tri­fluoro-2,4,6-tri­iodo­ben­zene (1/1), C6F3I3·C3H8N2S, 7, 1,3-di­methyl­thio­urea–1,1,2,2-tetra­iodo­ethene (1/1), C6H16N4S2·C2I4, 8, [(di­methylamino)­methyl­idene](1,2,2-tri­iodo­ethen­yl)sulfonium iodide–1,1,2,2-tetra­iodo­ethene–acetone (1/1/1), C5H8I3N2S+·I−·C3H6O·C2I4, 9, 2-amino-4-methyl-1,3-thia­zol-3-ium iodide–1,1,2,2-tetra­iodo­ethene (2/3), 2C4H7N2S+·2I−·3C2I4, 10, and 4,4-dimethyl-4H-1,3,5-thia­diazine-3,5-diium diiodide–1,1,2,2-tetra­iodo­ethene (2/3), 2C5H12N4S2+·4I−·3C2I4, 11. When utilizing the common halogen-bond-donor mol­ecules 1,2-, 1,3-, and 1,4-di­iodo­tetra­fluoro­ben­zene, as well as 1,3,5-tri­fluoro-2,4,6-tri­iodo­ben­zene, bifurcated I⋯S⋯I inter­actions were observed, resulting in the formation of isolated rings, chains, and sheets. Tetra­iodo­ethyl­ene (TIE) provided I⋯S⋯I cocrystals as well, but further yielded a sulfonium-containing product through the reaction of the S atom with TIE. This particular sulfonium motif is the first of its kind to be structurally characterized, and is stabilized in the solid state through a three-dimensional I⋯I halogen-bonding network. Thio­urea reacted with acetone in the presence of TIE to provide two novel heterocyclic products, again stabilized in the solid state through I⋯I halogen bonding.