2,4-二硫基胸腺嘧啶的异构化和质子迁移的理论研究

Theoretical Study on Tautomerism and Proton Transfer of 2,4-Dithiothymine

采用密度泛函方法在B3LYP/ 6 3 1+G 水平上研究了 2 ,4 二硫基胸腺嘧啶孤立分子和水合物的异构体的相对稳定性和可能的质子迁移反应 ,分析了水分子的参与对 2 ,4 二硫基胸腺嘧啶异构体的相对稳定性和质子迁移速率的影响 .结果表明 ,该分子在气相中只存在一种稳定构型 ,水分子的参与未改变 2 ,4 二硫基胸腺嘧啶各异构体的稳定性顺序 。

The DFT (B3LYP/6-31 + G*) method was used to study the relative stabilities and probable proton transfer in isolated and monohydrated 2,4-dithiothymine molecules in gas phase. The effects of water on relative stabilities and the rate of the proton transfer were analysed. The results indicate that only one tautomer for 2, 4dithiothymine can exist in gas phase. The interaction with one water molecule dose not change the order of relative stability and decreases the activation barriers of the proton transfer reactions for 2,4-dithiothymine.