Qualitative and Quantitative Study on Internal Rotation During Tautomerization of Thione, Selenone, and Tellurone

Resumo

Internal rotation during the tautomerization of simple acetone analogues of sulfur, selenium, and tellurium is investigated in detail both qualitatively and quantitatively. An enhanced HOMO-LUMO gap and thus, an increased stability in the product, which is evident from the qualitative analysis of frontier molecular orbitals of different rotamers of enol analogues, can be attributed to the consequences of this internal rotation. The effect of various substituents on the reaction mechanism and tautomerization energy is also investigated.