Formation of T-Shaped versus Charge-Transfer Molecular Adducts in the Reactions Between Bis(thiocarbonyl) Donors and Br2 and I2

The reactions of 4,5,6,7-tetrathiocino-[1,2-b:3,4-b′]-1,3,8,10-tetrasubstituted-diimidazolyl-2,9-dithiones (R2,R′2-todit; 1: R=R′=Et; 2: R=R′=Ph; 3: R=Et, R′=Ph) with Br2 exclusively afforded 1:1 and 1:2 “T-shaped” adducts, as established by FT-Raman spectroscopy and single-crystal X-ray diffraction in the case of complex 1⋅2 Br2. On the other hand, the reactions of compounds 1–3 with molecular I2 provided charge-transfer (CT) “spoke” adducts, among which the solvated species 3⋅2 I2⋅(1−x)I2⋅x CH2Cl2 (x=0.94) and (4)2⋅7 I2⋅x CH2Cl2, (x=0.66) were structurally characterized. The nature of all of the reaction products was elucidated based on elemental analysis and FT-Raman spectroscopy and supported by theoretical calculations at the DFT level.