Hole Burning Studies of Electric Fields in Organic Solids

有机固体电场的烧孔研究

• 批准号: 9417103
• 负责人: Eric Chronister
• 金额: $ 42.89万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-12-01 至 1997-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9417103&HistoricalAwards=false
• 关键词: Hole; Burning; Studies; Electric; Fields

In this project in the Physical Chemistry Program of the Chemistry Division, Prof. Bryan E. Kohler of the University of California at Riverside will engage in a study of electric fields in organic solids using the technique of hole burning spectroscopy. Previous successes for measuring and interpreting the effects of external electric fields on transition energies are the bases for the proposed research to map out the internal electric fields at a molecular site in a molecular system. Specifically, the effets of electric fields on linear polyene excitation energy, and the effect of external pressure on the effect of electric field on linear polyene excitation energy, will be determined for a number of different guest-host systems where the geometry can be calculated by standard molecular dynamics techniques. More complex systems will become available for investigation with the refinement of the interpretative model through a combination of measurement and theoretical simulation. Most theoretical models used for the determination of internal electric fields assume the point dipole approximation, which is found to be only qualitatively successful. The proposed investigations are designed to experimentally measure the fields using polyene doped alkane crystals. Much of our understanding of electronic structure of organic solid solutions is derived from optical spectroscopy. The amount of unambiguous information that can be extracted from a given optical spectrum is increased if the ensemble under investigation is made more homogeneous. This may be done by one of several methods of high resolution site selective spectroscopy, e.g., hole burning spectroscopy. With this technique resolution enhancements by a factor of up to one hundred thousand have been achieved. This in turn has allowed the investigations of relaxation processes such as, for example, optical dephasing, and spectral diffusion; energy transfer in organic solids; the characterization of photophysical processes in biological systems; applications of organic polymers to optical data storage and holography; and others. The research to be conducted in this project will contribute to a better understanding of optical processes in diverse solid organic systems and may lead to improved materials used in optical and electronic devices.

在化学系物理化学项目的这个项目中，加州大学河滨分校的 Bryan E. Kohler 教授将利用烧孔光谱技术研究有机固体中的电场。 先前在测量和解释外部电场对跃迁能量的影响方面取得的成功是拟议研究绘制分子系统中分子位点的内部电场的基础。 具体来说，对于许多不同的客主系统，将确定电场对线性多烯激发能的影响，以及外部压力对电场对线性多烯激发能的影响的影响，其中几何形状可以通过下式计算：标准分子动力学技术。 通过测量和理论模拟的结合来完善解释模型，更复杂的系统将可用于研究。 大多数用于确定内部电场的理论模型都假设点偶极近似，这被发现仅在定性上是成功的。 所提出的研究旨在通过实验测量使用多烯掺杂烷烃晶体的场。 我们对有机固溶体电子结构的大部分理解都来自光谱学。 如果所研究的系综变得更加均匀，则可以从给定光谱中提取的明确信息量就会增加。 这可以通过高分辨率位点选择性光谱法的几种方法之一来完成，例如烧孔光谱法。 通过这项技术，分辨率提高了十万倍。 这反过来又允许研究弛豫过程，例如光学移相和光谱扩散； 有机固体中的能量转移； 生物系统中光物理过程的表征； 有机聚合物在光学数据存储和全息术中的应用； 和其他人。 该项目将进行的研究将有助于更好地理解不同固体有机系统中的光学过程，并可能改进光学和电子设备中使用的材料。