Spectroscopic Studies of Clusters and Aggregates

团簇和聚集体的光谱研究

• 批准号: 184077-2013
• 负责人: Jaeger, Wolfgang
• 金额: $ 7.21万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=632434
• 关键词: Spectroscopic; Studies; Clusters; Aggregates

The research proposal describes a program to study matter in size regimes from the microscopic, molecular world to the nano-scale by the characterization of molecular aggregates. These studies are largely enabled by a revolution in high resolution spectroscopy both in terms of the development of new, more powerful spectroscopic techniques and its successful application to ever larger molecular systems. In the intermediate size regime, we propose to study clusters of helium atoms, and those of hydrogen molecules, doped with molecular chromophores, such as carbon monoxide or hydrogen cyanide. The results will shed further light on how a bulk phase property, namely superfluidity, evolves from the microscopic scale. Superfluidity is a consequence of the bosonic (integer composite spin) character of the constituent particles. We are particularly interested in using the fermionic 3-helium and HD as solvent species. The detection of superfluid effects in these cases would challenge current interpretations. Our newly constructed chirped pulse Fourier transform microwave spectrometer will make these studies possible. Much larger helium nanodroplets, which can consist of about a thousand to millions of helium atoms will serve as nano-cryostats and nano-reactors for the study of low temperature reactions of atmospheric and astrophysical importance. Emphasis will be on barrier-less reactions, such as carbon chain lengthening reactions involving carbon atoms and hydroxyl radical reactions. The reactive species will be produced by laser ablation or laser induced photodissociation of a precursor, such as hydrogen peroxide. A third research area concerns the formation of even larger aggregates, namely secondary organic aerosols ('smog'). These aerosols can have significant effects on climate and human health. Our studies will contribute to the improvement of atmospheric chemistry models.

研究建议描述了一项计划，该程序通过分子骨料的表征从显微镜，分子世界到纳米级的尺寸制度。这些研究在很大程度上是由高分辨率光谱范围的革命在新的，更强大的光谱技术的发展及其成功应用于更大的分子系统上的成功来实现的。在中间大小的状态下，我们建议研究氦原子的簇，以及氢分子的簇，掺有分子发色团（例如一氧化碳或氰化氢）的氢分子。结果将进一步阐明大量相位特性，即超过的超流量，从微观量表演变。超流体是组成颗粒的骨气（整数复合自旋）特征的结果。我们对使用费米子的3螺旋和HD作为溶剂物种特别感兴趣。在这些情况下，检测超流体效应将挑战当前的解释。我们新建造的脉搏傅立叶变换微波光谱仪将使这些研究成为可能。大约由大约一千至数百万氦原子组成的氦纳米光子将充当纳米晶体和纳米反应器，以研究大气和天体物理重要性的低温反应。重点将放在无障碍反应上，例如涉及碳原子和羟基自由基反应的碳链延长反应。反应性物种将通过激光消融或激光诱导的前体的光解离并产生，例如过氧化氢。第三个研究领域涉及甚至更大的聚集体的形成，即二级有机气溶胶（“烟雾”）。这些气溶胶可能会对气候和人类健康产生重大影响。我们的研究将有助于改善大气化学模型。