2-吡啶酮及其衍生物二聚体的分子内激发态质子转移机理研究

项目名称： 2-吡啶酮及其衍生物二聚体的分子内激发态质子转移机理研究

项目编号： No.21303255

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 龙金友

作者单位： 中国科学院武汉物理与数学研究所

项目金额： 25万元

中文摘要： 吡啶酮衍生物，作为最简单的一类碱基类似物，可以在醇亚胺构型与烯胺酮构型之间发生互变异构，该异构过程伴随着一个质子的转移。2-吡啶酮与2-羟基吡啶分子之间的质子转移就是这样一个典型的例子，该质子转移过程已经得到了许多谱学方法的研究，可是其动力学过程还是未知的。吡啶酮衍生物分子之间通过氢键作用可以形成二聚体，比如二聚体分子(3-甲基-2-吡啶酮)o(2-羟基吡啶)、(3-甲基-2-吡啶酮)o(2-氨基吡啶)，它们的质子转移发生于分子内的N-H…N、O-H…O或N-H…O氢键之上，对于这类质子转移动力学的观测目前仍然稀少。本项目拟利用飞秒时间分辨光电子影像技术实时观测如上三种分子体系中的激发态质子转移动力学，并结合量化计算，揭示该类碱基对类似物中激发态质子转移机理，建立起简单的质子转移模型，以帮助理解发生于DNA碱基对中的O-H…O与N-H…O氢键之上的质子转移是如何影响DNA损伤或突变的问题。

中文关键词： 飞秒时间分辨光电子影像；激发态；非绝热动力学；；

英文摘要： As the smallest base analog，pyridone derivatives are prone to tautomeric reaction between their enol form and keto form tautomers which is accompanied by the transfer of a proton. Prototropic tautomerisation between 2-pyridone and 2-hydroxypyridine has served as an excellent prototype. This prototropic tautomerism has been extensively investigated by various spectroscopic methods, however, its dynamics is still unknown. Pyridone derivatives can form homodimers or mixed dimers through hydrogen-bond interactions, for example, mixed dimers of (3-methyl-2-pyridone)o(2-hydroxypyridine) and (3-methyl-2-pyridone)o( 2-aminopyridine) can undergo a double proton transfer that exchanges between N-H…N、O-H…O or N-H…O hydrogen bonds. However, their direct time-resolved experimental observations are rare. We intend to study the excited-state proton tranfer dynamics of these molecules mentioned above by femtosecond time-resolved photoelectron imaging technique, which could preceed a real-time observation of the proton tranfer process. In combination with quantum chemical calculations, these studies will moldel and elucidate the excited-state proton tranfer mechanism of this kind of base pair analog, providing more insight into the mutation mechanism of DNA caused by double proton transfer processes between O-H…O or N-H…O hydrog

英文关键词： Femtosecond time-resolved photoelectron imaging；Excited state；Non-adiabatic dynamics；；