无和性和溶剂作用对OH激素对核基的攻击的重要性
Anna Thorn Ekstrøm1, Vera Staun Hansen1, Stephan P A Sauer1
1Department of Chemistry, University of Copenhagen, 2100 Copenhagen, Denmark.
这项研究研究了与核基的基基反应,发现溶剂效应显著影响反应速率,而不是不协调性. 计算的速率高于实验值,这表明OH激素反应建模需要进一步改进.
科学领域:
- 计算化学计算化学
- 化学动力学 化学动力学
- 生物分子化学 生物分子化学
背景情况:
- 之前对与核基的OH基反应的研究依赖于气相计算.
- 这些气相模型确定了C5-C6添加在pyrimidines和C8添加在purin中的关键路径.
- 从胺中提取气也被认为是显著的反应途径.
研究的目的:
- 为了研究溶剂效应和不协调性对与核基的OH基反应的影响.
- 改进反应路径和速率常数的理论预测.
- 为了比较溶剂模型的影响与不协调性纠正.
主要方法:
- 密度函数理论 (DFT) 在 ωB97-D/6-311++G ((2df,2pd) 层面的计算.
- 极化连续模型 (PCM) 用于溶剂校正的应用.
- 包括埃卡特道校正和不协调性分析.
主要成果:
- 确定了腺素,关氨酸,胆氨酸,细胞氨酸和 uracil 的计算反应速率常数.
- 计算速度大约比实验值高出两个数量级.
- 发现溶剂效应对反应参数的影响比不协调性更大.
结论:
- 溶剂校正和无和性分析完善了对OH基与核基反应的理解.
- 包括溶剂效应在内显著改变了反应能量和反应途径.
- 虽然无和性影响了一些反应,但溶剂效应对整体反应场景产生了更广泛的影响.
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