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4(3H)-嘧啶酮及其类似物(5-氟-4(3H)-嘧啶酮、4-巯基嘧啶和5-氟-4-巯基嘧啶)醇式结构和酮式结构进行结构互变质子迁移过程中的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所需要的活化能较小.研究还表明,氢键在降低反应活化能方面起着重要的作用.
The processes of the proton transfer between the keto tautomer and the enol one of 4（3H） - pyrimidinone and its analogues were investigated by using density functional theory at B3LYP/6- 311 G^＊ ＊ level. The two possible reaction pathways are： （a） intramolecular proton transfer; （b） water assisted intermolecular transfer. The calculated results showed that process （b） has lower activation energies than that of （a） because of the formation of hydrogen bonded complexes in （b）. It is likely that the hydrogen bonds formed in the complexes play an important role in lowering the activation energy.
出处
《化学研究》
CAS
2007年第1期54-56,共3页
Chemical Research
关键词
4(3H)-嘧啶酮
互变异构
构象异构
密度泛函理论
4（3H）-pyrimidinone
tautomerization
conformational isomerization
density functional theory
