Instrumentation for Rapid Inorganic Kinetics (Chemistry)

该奖项将支持建设一个脉冲加速 流动分光光度计 光诱导电子转移反应。这种类型的 仪器可以记录物种的光谱 其寿命短至十万分之一秒， 测量在如此短的时间内发生的反应速率 时间跨度，但尚未商业化。几乎所有 光驱动的能量转换过程在某种程度上依赖于 电子传递反应，包括光合作用。之一 使用合成物质的最有希望的方案 用于光驱动的能量转换涉及使用 含有两种金属的分子。光的吸收导致 一个电子在金属原子之间转移， 一种高能量分子， 当电子返回到其优选位置时， 位置. 本项目采用了两种新方法， 热分子内电子转移的直接评价 rates.其中第一个利用优先溶剂化 使不对称的混合价氧化还原异构体相互转化， 双核金属配合物脉冲加速流 分光光度法被用于时间分辨氧化还原 异构化过程第二种方法基于 光诱导（脉冲激光）金属-金属电荷转移 近红外产生高能异构体， 混合价络合物电子转移弛豫 创建低能量异构体可以遵循在可见光 瞬态吸收光谱法该项目得到了 一部分是总统青年调查员奖。

This award will support the construction of a pulse-accelerated flow spectrophotometer for use in the study of rapid light-induced electron transfer reactions. This type of instrumentation allows the recording of spectra for species with lifetimes as short as 1/100,000-th of a second and the measurement of rates of reactions which occur over such a short time span, but is not yet commercially available. Nearly all light-driven energy conversion processes rely at some point on electron transfer reactions, including photosynthesis. One of the most promising schemes for the use of synthetic substances for light-driven energy conversion involves the use of molecules containing two metals. The absorption of light causes an electron to be transferred between the metal atoms to create a high energy molecule from which electrical or chemical energy may be extracted as the electron returns to its preferred location. Two new approaches are being used in this project for the direct assessment of thermal intramolecular electron transfer rates. The first of these makes use of preferential solvation to interconvert mixed-valence redox isomers of unsymmetrical binuclear metal complexes. Pulse accelerated flow spectrophotometry is being used to time-resolve the redox isomerization process. The second approach is based on light-induced (pulsed laser) metal-to-metal charge transfer in the near IR to create high energy isomers, again in mixed-valence complexes. Relaxation by electron transfer to create low energy isomers can be followed in the visible by transient absorbance spectroscopy. This project is supported in part by a Presidential Young Investigator award.