Quantum mechanical investigation of 2,3-dihydro-1-methyl-2-thioxopyrimidin-4(1H)-one tautomers and their complexes with iodine.

Abstract

DFT and AB initio theoretical methods were used to calculate the relative stability of tautomers and complexes with iodine in the 2,3-dihydro-1-methyl-2-thioxopyrimidin-4(1H)-one. This compound can be used to treat hyper thyroidism due to their ability to make complexes with iodine.All tautomers and complexes are optimized using the B3LYP Method with two different energies, the relative energies shows that in all tautomers and complexes. Thione forms are more stable than thieolforms.The NBO calculation is carried out for tautomers and complexes to obtain atomic charges and accept donor interactions. These result confirm the ability of T tautomers to form complexes and show that the planar complexes has more effective interaction than the perpendicular complex.The atom in molecule (AIM) analysis show that the charge density and its laplacian at the S-I bond critical point of the planar complex is greater than the perpendicular complex.