High resolution laser spectroscopy of small gas-phase metal-ligand molecules

小气相金属配体分子的高分辨率激光光谱

• 批准号: 105922-2011
• 负责人: Adam, Allan
• 金额: $ 2.55万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=569120
• 关键词: resolution; laser; spectroscopy; small; gas

This research program is geared towards understanding the fundamental structure and properties of small, gas-phase, metal-ligand molecules using laser spectroscopy. The molecules are produced by various methods and excited with a laser to higher energy states from which they can decay back to lower energy levels by emitting light. By detecting either this emitted light or observing at which energy the molecules absorb the radiation, a detailed understanding of the bonding, structure and interactions in the molecules can be gained. This information is important, for example, in understanding both the chemical and physical processes occurring in the atmosphere, in space, and in any surface chemistry or catalytic process. The molecules are produced in cold molecular beams (well defined streams of molecules) to give highly resolved and simplified spectra. In the experiments, a high power laser is focussed onto a metal target held in front of a pulsed gas nozzle. Vaporized atoms from the target react with a reagent in the gas flowing from the nozzle. The gases then expand through a small hole into a vacuum system creating the beam. The molecules are probed downstream with a tunable laser and molecular absorptions are observed as a function of frequency. Two groups of molecules are targeted in the research: A) diatomic metal-ligand species (DMLs), and B) small metal-ligand polyatomics (MLPs). We are measuring a number of DMLs (RhBr, RhP,IrP, ...), where absorptions for these molecules are being observed for the first time, to comprehensively study the bonding characteristics and provide spectral information for certain molecules of catalytic and astrophysical interest. There are many MLPs. We are interested in MLPs that have astrophysical importance or are important for understanding catalysis and chemisorptions. A few MLP molecules that we have studied recently are: MgCCH/C4H, CaCCH/CCD, Ca/SrOCH3. We are particularly interested in metal monocarbonyls. Few gas-phase studies of these molecules, which are important in surface chemistry and catalytic reactions, exist. We will examine these species for the first time to provide new information on their properties.

该研究计划旨在利用激光光谱了解小型气相金属配体分子的基本结构和性质。这些分子是通过各种方法产生的，并用激光激发到较高的能态，然后它们可以通过发射光衰变回较低的能级。通过检测发射的光或观察分子吸收辐射的能量，可以详细了解分子中的键合、结构和相互作用。例如，这些信息对于理解大气、太空以及任何表面化学或催化过程中发生的化学和物理过程非常重要。 这些分子在冷分子束（明确定义的分子流）中产生，以提供高分辨率和简化的光谱。在实验中，高功率激光被聚焦到固定在脉冲气体喷嘴前面的金属目标上。来自目标的汽化原子与从喷嘴流出的气体中的试剂发生反应。然后气体通过一个小孔膨胀到真空系统中，从而产生光束。使用可调谐激光探测下游分子，并观察分子吸收随频率的变化。 研究的目标是两组分子：A) 双原子金属配体物种 (DML) 和 B) 小金属配体多原子 (MLP)。我们正在测量许多 DML（RhBr、RhP、IrP...），首次观察到这些分子的吸收，以全面研究键合特性并为某些具有催化和天体物理意义的分子提供光谱信息。 MLP 有很多。我们对具有天体物理学重要性或对于理解催化和化学吸附很重要的 MLP 感兴趣。我们最近研究的一些MLP分子有：MgCCH/C4H、CaCCH/CCD、Ca/SrOCH3。我们对单羰基金属特别感兴趣。这些在表面化学和催化反应中很重要的分子的气相研究很少。我们将首次检查这些物种，以提供有关其特性的新信息。