Abstrakt

Computational study of the charge transfermolecular complexes of 3-methyl-2-thioxoimidazolidin-4-one with I2, IBr, and ICl

TayebehHadadi, PouyaKarimi

Imidazoline derivatives can be used to treat hyperthyroidism due to their ability to make complexes with iodine. DFT and ab initio theoretical methods were used to calculate the relative stability of the molecular complexes between 3-methyl-2-thioxoimidazolidin-4-one (T) and the dihalogens IY (Y = Cl, Br, I). Stereoisomeric energy minima have been studied for thioamide system. It presents a collinear S–I–Y geometry and was distinguished by the geometry of the dihalogen IY molecular axis located at either a planar or a perpendicular arrangement with respect to the 3-methyl-2-thioxoimidazolidin-4-one(T) plane. The results show that the planar complexes have more effective interaction than the perpendicular ones. Also,the results reveal interesting correlations of various structural and frequency features like the C–S and S–I bonding distances and the N–H stretching frequency shifts with the enthalpy of complexation, the electron donor–acceptor capacity of the dihalogen and the electronegativity of the Y atom and the strength of the interaction between the amidic hydrogen and the inner I.