振动激发态分子的反应动力学研究

Under the support of the NSFC major research plan “Detection and Interaction of Single Quantum State”, we carried out researches on preparation of molecular beam in single quantum state and their interactions with other atoms/molecules, and achieved important progress on molecular reaction dynamics with reagent molecules in their ground vibrational state, as well as on the techniques to prepare molecule beams in vibrational excited states. In this integration proposal, we plan to conduct joint theoretical and experimental studies on reaction and photodissociation dynamics of H2, H2O, NH3, CH4 molecules and their isotope analogies in their vibrationally excited states. Vibrational excited reagents play important roles in many important combustion, atmospheric, and interstellar processes, therefore are of practical importance to life and production of our society. On experimental side, we will further develop the techniques to prepare vibrational excited molecular beams through controlled coherent excitations and to detect molecules with quantum states resolved. Theoretically, we will construct accurate potential energy surfaces and develop state-to-state quantum dynamics methods for polyatomic reactions. The joint research will not only improve our experimental and theoretical capabilities on studying molecular dynamics in vibrational excited states, but also improve our understanding of fundamental mechanisms of molecular dynamics in vibrational excited states and their roles in combustion, atmospheric, and interstellar processes, as well as help us to exploit control of chemical reaction through reagent vibrational excitations.

在重大研究计划“单量子态的探测及相互作用”的支持下，我们在分子单量子态制备与相互作用研究方面开展了一系列研究工作，在振动基态分子反应动力学研究与振动态激发分子束制备技术发展方面取得了重大进展。本集成项目拟紧密结合量子动力学理论与分子束实验，深入研究振动激发态H2,H2O,NH3，CH4等分子及其它们同位素取代物反应与光解动力学。振动激发的反应物分子在许多重要的燃烧、大气、星际化学反应过程中广泛存在并扮演了重要的角色，对人类的生产和生活具有实际的意义。实验上进一步发展基于相干激发的振动态激发分子束制备技术和分子量子态探测技术；理论上构建高精度势能面和发展多原子态-态动力学方法。研究不仅将极大提高我们的振动态激发分子动力学实验与理论研究能力，也将提高我们对振动态激发分子动力学本质机理及其在燃烧、大气、星际化学过程中所扮演角色的认识，帮助我们探索利用振动激发控制化学反应。

在项目执行期间，我们按研究计划，大力发展振动态激发分子束制备技术和分子量子态探测技术，特别是在氢分子振动激发态制备技术上获得重大突破，使在交叉分子束中研究氢分子振动激发态动力学成为可能；在理论方面，我们极大发展了含时波包法以及基于神经网络的多原子反应体系势能面构造方法。项目通过理论与实验的紧密结合，在F+HD(v=1)反应中发现了只有能通过HD振动激发得以探测的反应共振态；发现并解释了Cl+HD(v=1)反应中，化学键软化所造成的反应共振态具有相当的普遍性；在SO2光激发过程的非绝热动力学研究中，理论和实验共同揭示了S同位素在SO2激发态动力学中的非质量同位素效应；在理论上对H+H2O初始基态、第一对称和反对称伸缩振动激发态反应进行了全维态-态量子动力学研究，证实了不反应的OH键在反应中作为旁观者；在水在金属表面解离动力学研究中，首次发展了7维的量子动力学模型，通过计算发现6维结果与7维结果有很大差别，6维模型很不精确。这些研究提高了我们对化学反应本质机理的认识，推动了分子反应动力学研究的发展。项目期间，共发表了39篇SCI文章，其中包括2篇Science, 1篇PNAS, 1篇Chemical Science, 3篇J. Phys. Chem. Lett.。