中文摘要：

采用密度泛函理论，在B3LYP／6—311G^＊＊基组水平上，计算并考察了2-巯基嘧啶分子硫酮式和硫醇式结构进行结构互变的质子迁移过程中的2种可能途径：（a）分子内质子迁移，（b）水助质子迁移．计算结果表明，途经（b）所需的活化能较小，氢键在降低反应活化能方面起着重要作用．

英文摘要：

The processes of the proton transfer between the thione tautomer and the thiol tautomer of 2-thiopyrimidine were investigated by using density functional theory at B3LYP/6-311G^＊＊ level. The two possible reaction pathways： （a） intramolecular proton transfer; （b） water-assisted intermolecular transfer. The calculated results showed that the processes （b） has lower activation energies than those of the processes （a） because of the form action of hydrogen-bonded complexes in （b）. It is likely that the hydrogen bonds formed in the complexes play an important role in proton transfer processes in the latter reaction pathway.