Structural and DFT Studies of Dibromine and Diiodine Adducts of a Sulfur‐Rich Thiocarbonyl Donor

4,5‐Bis(benzoylthio)‐1,3‐dithiole‐2‐thione ( 1 ) forms molecular adducts with dibromine ( 2 ) and diiodine ( 3 ), which display a range of complementary primary X–X and S–X and secondary S ··· X and X ··· X bonding interactions. Compounds 2 and 3 were characterised by X‐ray diffraction analysis and FT‐Raman spectroscopy. Compound 2 , which is derived from the additive dibromine oxidation of 1 , features a near linear Br–S–Br moiety that is coplanar with the dithiole‐2‐thione heterocycle. The S–Br bonds in 2 are asymmetric; the asymmetry arises mainly through a combination of intramolecular S ··· Br bonds between the Br atoms and the thioether S atoms of the donor, and an intermolecular S ··· Br contact between one of the bromine atoms and the hypervalent S atom of an adjacent molecule. DFT calculations carried out on 2 with different functionals agree and show that the geometry featuring the SBr 2 moiety coplanar with the heterocycle is more stable by about 9 kcal mol –1 than that with the SBr 2 unit perpendicular to the plane of the heterocycle. DFT calculations indicate that the formation of 2 can be explained based on the charge distribution on the hypothetical cationic intermediate [ 1 –Br] + . Diiodine complex 3 is a molecular charge‐transfer species, with an almost linear S–I–I moiety. The unit cell contains two molecules of donor 1 , related by a centre of inversion, which form a dimer pair held together by two intermolecular S ··· S and two S ··· O contacts. The packing of the dimers generates various cavities that are able to accommodate I 2 molecules as “guests”, in one case the guest diiodine molecule bonds with the sulfur atoms of the benzoylthio‐groups and acts as a bridge between adjacent dimers, in another the diiodine is disordered along the channel‐like cavity. The terminal iodine atom of each S–I–I fragment interacts with two additional I 2 molecules leading to infinite chains in the [01–1] direction.