Resonance Raman Studies of Solvent Dynamics in Solvatochromic Systems

溶剂变色系统中溶剂动力学的共振拉曼研究

• 批准号: 9802075
• 负责人: Jeanne McHale
• 金额: $ 32.2万
• 依托单位: Regents of the University of Idaho
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-06-01 至 2002-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9802075&HistoricalAwards=false
• 关键词: Resonance; Raman; Studies; Solvent; Dynamics

McHale is supported by the Experimental Physical Chemistry Program for studies to elucidate solvent dynamical influences on the optical spectra of solvatochromic molecules. The program includes (1) measuring absorption, emission, and resonance Raman spectra in low-temperature glass, in order to isolate the intramolecular contribution to the linewidth, (2) employing solvent isotopomers to isolate solvent dynamical effects on absorption, emission, and resonance Raman spectra in room temperature solvents, and (3) determining fluorescence yields and lifetimes as a function of solvent isotopic substitution in order to obtain radiative and nonradiative decay rates in glass and liquid phase solutions. These strategies will enable the extraction of the solvent-induced dephasing function, and hence the solvent spectral density. Issues to be addressed include the sensitivity of radiative and nonradiative relaxation rates to solvent isotopomer, the validity of treating solvent response as independent of the solute electronic state, the possible dependence of solvent-induced electronic dephasing on vibrational mode, and the role of solvent intramolecular modes in electronic dephasing. Molecules dissolved in liquid solvents exhibit behaviors that are much affected by the solvent molecules in the surrounding environment. These interactions are complex and still not understood well at this time. Results from this project will help to bridge the gap between theoretical predictions and real systems in understanding solution dynamics. Fundamental insights from this work could improve both the description of electron transfer processes relevant to biochemistry and the molecular models for nonlinear optical properties relevant to materials science.

麦克海尔在实验物理化学计划的支持下，研究溶剂动力学对溶剂致变色分子光谱的影响。该程序包括(1)测量低温玻璃中的吸收、发射和共振拉曼光谱，以分离分子内对线宽的贡献；(2)使用溶剂同位素体分离溶剂动力学对室温溶剂中的吸收、发射和共振拉曼光谱的影响。(3)测定荧光产率和寿命作为溶剂同位素取代的函数，以获得玻璃和液相溶液中的辐射和非辐射衰变率。这些策略将使溶剂诱导的脱相函数的提取，从而溶剂的光谱密度。需要解决的问题包括辐射和非辐射弛豫速率对溶剂同位素体的敏感性，将溶剂反应视为独立于溶质电子态的有效性，溶剂诱导的电子脱相可能依赖于振动模式，以及溶剂分子内模式在电子脱相中的作用。溶解在液体溶剂中的分子表现出的行为受到周围环境中溶剂分子的很大影响。这些相互作用是复杂的，目前还没有被很好地理解。这个项目的结果将有助于弥合理论预测和理解解动力学的实际系统之间的差距。这项工作的基本见解可以改善与生物化学相关的电子转移过程的描述，以及与材料科学相关的非线性光学性质的分子模型。