Franck-Condon Active Intermolecular Vibrations in Condensed Phases

罗切斯特大学的安妮·迈尔斯得到了 实验物理化学计划在她的继续研究， 她利用共振拉曼和荧光光谱 表征发色团的电子跃迁与 核自由度在周围环境中的液体和 无定形固体。 将进行三种类型的实验：（一） 分子离子的拉曼谱线宽度将在共振与 非共振激励条件，以测试假设， 先前观察到的共振线宽的增加是由于耦合 发色团局部振动的溶剂或分子间 声子;（ii）共振激发发射光谱将被测量为 温度和光谱的函数将被建模，以更好地 理解温度依赖性;（iii）低温荧光 线窄化光谱将在发色团/基质中测量 组合来研究偶联的生色团依赖性， 声子频率和耦合强度。 这些调查将提供洞察力的过程， 负责电子散射的扩展在凝聚 介质和影响冷凝器中化学反应速率的过程 阶段。 努力开发实用的基于 固体中持续的光谱烧孔将有助于更好的 从这项研究中得到的理解。

Anne Myers of the University of Rochester is supported by the Experimental Physical Chemistry Program in her continuing studies in which she uses resonance Raman and fluorescence spectroscopies to characterize the coupling of electronic transitions of a chromophore to nuclear degrees of freedom in the surrounding environment in liquids and amorphous solids. Three types of experiments will be carried out: (i) Raman linewidths for molecular ions will be compared under resonant vs. nonresonant excitation conditions to test the hypothesis that the previously observed increase in linewidth on resonance is due to coupling of the chromophore-localized vibrations to solvent or intermolecular phonons; (ii) resonantly excited emission spectra will be measured as a function of temperature and the spectra will be modeled to better understand the temperature dependence; (iii) low-temperature fluorescence line-narrowing spectra will be measured in chromophore/matrix combinations to investigate the chromophore dependence of the coupled phonon frequencies and coupling strengths. These investigations will provide insight to the processes that are responsible for the broadening of electronic absorptions in condensed media and to processes that affect chemical reaction rates in condensed phases. Efforts to develop practical optical memory devices based on persistent spectral hole burning in solids will be aided by a better understanding resulting from this research.