Electric Field Effects on Excited State and Electron Transfer Dynamics

这项由无机化学、生物无机化学和金属有机化学项目颁发的奖项支持斯坦福大学的Stephen G.Boxer教授继续研究光谱方法的开发，该方法探测由相对较长的间隔基团分隔的分子片段之间的相互作用。斯塔克效应光谱用于提供与光谱转变相关的电荷位移的大小和方向的定量信息。外加电场对电子或振动跃迁的影响被用来加深对成键的理解，特别是在配位络合物中，以及振动频率漂移可以作为复杂体系(如蛋白质)中静电效应的定量探针的概念。初步结果表明，振动斯塔克光谱可以是一种强大的、微创的方法来获得关于修饰蛋白质中和催化过程中蛋白质静电场如何变化的信息。这项工作首先概述了当生化反应产生、消耗或移动电偶极子时，如何利用电场来控制电子和质子的转移速率。在混合价络合物中可能会出现不寻常的、特有的非经典斯塔克效应，因为混合价络合物的能级差异受外加电场的影响。对产生的异常线形的分析将提供关于这些分子中的能量、电子耦合和电荷位移的定量信息。一种新的光谱学形式将用于研究电场如何影响化学、光化学和生物化学过程中的电子、质子和偶极运动。

This award by the Inorganic, Bioinorganic and Organometallic Chemistry program supports research by Professor Stephen G. Boxer of Stanford University to continue studies on the development of spectroscopic methods that probe interactions between molecular fragments separated by relatively long spacer groups. Stark effect spectroscopy is used to provide quantitative information on the magnitude and direction of charge displacement associated with a spectroscopic transition. The effect of an applied electric field on an electronic or vibrational transition is used to generate a deeper understanding of bonding, especially in coordination complexes, and the concept that the vibrational frequency shifts can be a quantitative probe for electrostatic effects in complex systems such as proteins. Initial results indicate that vibrational Stark spectroscopy can be a powerful and minimally invasive approach for obtaining information on how protein electrostatic fields change in modified proteins and during catalysis. This work begins to outline how electric fields can be used to manipulate the rates of electron and proton transfer as biochemical reactions create, consume or displace electric dipoles. Unusual and characteristic non-classical Stark effects are expected to occur in mixed-valence complexes that exhibit multiple states whose energy difference is affected by the applied field. Analyses of the resulting unusual line shapes will give quantitative information on the energetics, electronic coupling and charge displacement in these molecules.A new form of spectroscopy will be used to study how electric fields affect electron, proton and dipole movements in chemical, photochemical and biochemical processes.