Ultrafast Molecular Sciences

超快分子科学

• 批准号: RGPIN-2016-06677
• 负责人: Stolow, Albert
• 金额: $ 7.87万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=692934
• 关键词: Ultrafast; Molecular; Sciences

Molecular sciences in the 20th century was based on understanding the structure of the microscopic world. It is hard to overstate how important this was. Discerning the shapes of molecules and solids led to structure-function relationships which engendered Molecular Biology, computer chips, plastics and drug design. Nature, however, is not static: there are many rapid molecular processes underlying photosynthesis, vision, solar energy conversion etc. In the 21st century, we must go beyond structure' and develop a dynamical understanding of nature's processes. This proposal is directed towards this goal. Specifically, using novel ultrafast electron and X-ray techniques, we will study fundamental aspects of molecular dynamics, with a view towards developing simple rules' which govern how, on ultrafast (femtosecond) time scales, electronic charge and energy flow during such processes. Ultrafast Molecular Sciences is based on revolutionary advances in high power laser technology, now permitting ultrashort pulse generation from the infrared to the soft X-ray regions. This proposal builds on CFI-supported major infrastructure, with NSERC-supported HQPs carrying out the research program.******High power ultrashort pulse laser technology offers many new opportunities beyond generating IR or X-ray pulses. The electric forces associated with such light pulses can be even stronger than the electric forces which bind matter itself. This means that researchers can align or shape molecules using laser fields. Here, we will use our ability align molecules. Molecules are generally randomly oriented and therefore our studies of their dynamics are somewhat blurred. Much like forcing children to line up for a group photograph, we can use laser electric forces to line molecules up so that we may observe their dynamical processes much more clearly. We will develop techniques for aligning molecules in 3D, allowing us to apply our novel electron and X-ray spectroscopies to them with maximal benefit.******As ultrashort laser fields get even stronger, new physical processes occur. One process, called strong field ionization, has led to a new branch of physics called Attosecond Science, itself a Canadian invention. This field has produced the world's shortest light pulses and now permits researchers to study the fastest processes within molecules namely, how electrons move within molecules and materials. However, the models and techniques developed thus far only apply to very simple systems such as atoms. In order to broaden the scope, we will study how these attosecond methods apply to more complex molecules, a requirement for advancement.******Finally, we use ultrashort pulses to develop new forms of microscopy which permit chemical-specific imaging of samples without adding any dyes or stains. This new type of imaging is important for fields ranging from biomedicine, to material science, to natural resources.**

20世纪的分子科学是建立在对微观世界结构的理解之上的。这件事的重要性怎么强调都不为过。识别分子和固体的形状导致了结构-功能关系，从而产生了分子生物学、计算机芯片、塑料和药物设计。然而，自然界并不是静止的：光合作用、视觉、太阳能转换等背后有许多快速的分子过程。在21世纪，我们必须超越结构，发展对自然过程的动态理解。这一建议就是为了实现这一目标。具体地说，我们将使用新的超快电子和x射线技术，研究分子动力学的基本方面，以期制定简单的规则，以控制在超快（飞秒）时间尺度上，电子电荷和能量在这些过程中如何流动。超快分子科学基于高功率激光技术的革命性进步，现在允许从红外到软x射线区域的超短脉冲产生。该提案以cfi支持的主要基础设施为基础，由nserc支持的hqp执行研究计划。******高功率超短脉冲激光技术除了产生红外或x射线脉冲之外，还提供了许多新的机会。与这种光脉冲相关的电作用力甚至可能比束缚物质本身的电作用力更强。这意味着研究人员可以使用激光场排列或塑造分子。在这里，我们将利用我们的能力来排列分子。分子通常是随机定向的，因此我们对其动力学的研究有些模糊。就像强迫孩子们排队合影一样，我们可以用激光电力把分子排列起来，这样我们就可以更清楚地观察它们的动力学过程。我们将开发3D分子对齐技术，使我们能够将我们的新型电子和x射线光谱学应用于它们，并获得最大的收益。******随着超短激光场变得更强，新的物理过程就会发生。一种被称为强场电离的过程导致了物理学的一个新分支——阿秒科学，它本身就是加拿大人的发明。这个领域产生了世界上最短的光脉冲，现在允许研究人员研究分子内最快的过程，即电子如何在分子和材料内运动。然而，迄今为止开发的模型和技术只适用于非常简单的系统，如原子。为了扩大范围，我们将研究这些阿秒方法如何应用于更复杂的分子，这是进步的要求。******最后，我们使用超短脉冲来开发新形式的显微镜，它允许在不添加任何染料或污渍的情况下对样品进行化学特异性成像。这种新型成像技术对生物医学、材料科学、自然资源等领域都具有重要意义