Electric Field Effects on Excited State and Electron Transfer Dynamics

这个无机、生物无机和有机金属化学项目的奖项支持斯坦福大学化学系的Steven G. Boxer博士对应用电场中配合物的光物理学和反应动力学的研究。基于步进扫描FTIR的Stark光谱仪将用于获得中红外区域的高信噪比振动Stark效应光谱和电子Stark光谱，用于获得配位化合物的宽跃迁特征。Stark光谱研究的一些具体问题包括：II类混合价配合物和金属桥接的卟啉二聚体中的电子耦合；羰基和碳-氟拉伸的键不谐性；推拉多烯（用于非线性光学器件）的离域程度，这是由强电子供体和受体的附着引起的大内部电场所施加的；外加电场对3-羟基黄酮激发态质子转移反应的影响。由相对较长的和化学上有趣的间隔分隔的分子片段之间的相互作用将使用斯塔克效应光谱进行研究。电子或振动跃迁受到外加电场的影响，这种影响的测量提供了电荷位移的大小和方向的定量信息。电场也可以用来控制电子和质子转移反应的速率。这些结果不仅具有根本性的意义，而且可能适用于电子工业中使用的非线性光学材料的开发。

This award in the Inorganic, Bioinorganic, and Organometallic Chemistry Program supports research by Dr. Steven G. Boxer of the Chemistry Department, Stanford University, for investigation of the photophysics and reaction dynamics of coordination complexes in applied electric fields. A Stark spectrometer based on a step-scan FTIR will be developed for use in obtaining high signal-to-noise virbrational Stark effect spectra in the mid-IR region and electronic Stark spectra for the broad transitions characteristic of coordination compounds. Some of the specific problems to be investigated by Stark spectroscopy include: electronic coupling in class II mixed valence complexes and metal-bridged prophyrin dimers; bond anharmonicity in carbonyl and C-F stretches; degree of delocalization in push-pull polyenes (used in non-linear optical devices) imposed by large internal electric fields that result from the attachment of strong electron donors and acceptors; effect of applied electric fields on excited state proton transfer reactions in 3-hydroxyflavone. Interactions between molecular fragments separated by relatively long and chemically interesting spacers will be investigated using Stark effect spectroscopy. Electronic or vibrational transitions are affected by applied electric fields and measurement of this effect provides quantitative information on the magnitude and direction of charge displacement. Electric fields can also be used to manipulate the rates of electron and proton transfer reactions. The results are not only of fundamental interest but also potentially applicable to the development of non-linear optical materials for use in the electronics industry.