中文摘要：

在密度泛函理论B3LYP／6--31G（d）；基组水平上，计算了气相中6-氯烟酰胺分子酮式和烯醇式质子迁移异构化过程的2种可能途径：分子内直接质子迁移和水分子辅助质子迁移．结果表明，在气相中只存在。种稳定构型，水分子的参与降低了质子迁移过程的活化能．

英文摘要：

The processes of the proton transfer between the ketone tautomer and the enol tautomer of 6-chloronicotinamide are investigated by using density functional theory at B3LYP/6-31G（d）level. The two possible reaction pathways： （a） intramo-lecular proton transfer; （b） water-assisted intermolecular transfer are investigated. The calculated results show that only one tautomer for 6-chloronicotinamide can exist in gas phase. The interaction with one water molecule decreases the activation barriers of the proton transfer reactions for 6-chloronicotinamide.