Laser spectroscopy of isolated molecules and systems: structure, dynamics and analysis

本提案请求资金用于扩展NSERC资助的基础和应用分子光谱学研究项目。在分子物理界面的物理化学研究将使用脉冲激光辐射，在多共振激发序列中调谐，研究超激发小分子的弛豫动力学-在孤立和冷系中。在这里，我们将用光谱学来研究状态选择外逸电子的轨道能量和角动量与孤立分子阳离子的颤振自由度的耦合。我们将继续关注一组重要的高能，开壳多原子自由基中间体，目的是表征激发态结构和动力学。通过绘制振子位置和线形，我们将获得电子-阳离子散射的实验信息，以便与理论进行比较。其他实验将进一步扩展到研究非绝热分子间散射动力学，通过这种动力学，状态选择的高里德伯分子气体松弛形成冷等离子体。我们已经成功地建立了在NO中发生这种转变的条件。利用空间和速度图成像技术以及太赫兹频域的光谱探针的新工作将探索这种量子相变的多尺度结构和动力学表现。我们在分析化学方面的研究将探索新的仪器和信息学方法，促进拉曼光谱在从工业过程监测到分子生物学等背景下的多元材料分类中的应用。利用驱动物镜进行动态对准的研究将使我们能够设计新的制图和空间平均方法。我们将开发和表征强大的多元分类算法，使我们能够跟踪细微的光谱变化，目的是在不相关方差的存在下隔离目标签名。信息处理将扩展到合并光场线索，以建立新的化学计量驱动的智能扫描模式。

This proposal requests funds to extend and expand a program of NSERC sponsored research in basic and applied molecular spectroscopy. Research in physical chemistry at the interface with molecular physics will use pulsed laser radiation, tuned in multiresonant excitation sequences, to investigate the relaxation dynamics of superexcited small molecules - in isolation and in cold ensembles. Here, we will work spectroscopically to study the coupling of the orbital energy and angular momentum of state-selected extravalent electrons with the rovibrionic degrees of freedom of isolated molecular cations. We will maintain a focus on an important set of energetic, open-shell polyatomic free-radical intermediates with the objective of characterizing excited-state structure and dynamics. By charting rovibronic positions and lineshapes, we will obtain experimental information on electron-cation scattering for comparison with theory. Other experiments will extend further to study the nonadiabatic intermolecular scattering dynamics by which a gas of state-selected high-Rydberg molecules relaxes to form a cold plasma. We have succeeded in establishing conditions under which such a transformation occurs in NO. New work employing spatial and velocity map imaging techniques together with spectroscopic probes in the THz frequency domain will explore multiscale structural and dynamical manifestations of this quantum phase transition. Our research in analytical chemistry will explore novel instrumental and informatics methodologies that facilitate the application of Raman spectroscopy for multivariate materials classification in contexts ranging from industrial process monitoring to molecular biology. Research using dynamic alignment by means of actuated objectives will enable us to devise new mapping and spatial averaging approaches. We will develop and characterize powerful multivariate classification algorithms to enable us to track subtle spectral variations with the aim of isolating targeted signatures in the presence of uncorrelated variance. Information processing will extend to incorporate bright-field optical cues to establish new chemometrically driven smart-scanning modalities.