Molecular Photonic Materials

在这个项目中，由化学部的化学结构，动力学机制B计划资助，查佩尔山的北卡罗来纳州大学化学系的Gerald Meyer教授正在表征锚定在金属氧化物表面的分子的分子间电子转移反应。 这项研究的目标是利用自交换反应作为一种手段，在光电器件中的应用，即用于太阳能转化为储存的化学能或电力（例如染料敏化太阳能电池）的氧化物表面传输电荷。 该项目位于物理有机，无机和材料化学的界面，因此非常适合各级科学家的教育。 该小组也有能力为科学领域代表性不足的学生提供最高水平的教育和培训。 对北卡罗来纳州当地和农村小学生的外联活动也是资助项目的一部分。 研究表明，光氧化染料分子锚定到敏化介孔纳米晶（TiO 2）薄膜通常用于染料敏化太阳能电池进行自交换分子间电子转移反应（称为空穴跳跃）的动力学和效率，可以在分子水平上调整。 这些发现提供了一个机会，运输电荷到所需的位置，而不会损失吉布斯自由能。 特别关注的是要解决以下基本问题：如何调整分子结构来控制分子间的电子转移？ 流体溶液中的自交换反应与氧化物表面的自交换反应之间是否存在相关性？ 染料之间的自交换电子转移是否影响不需要的重组反应？ 含有两个（或更多）氧化还原活性基团的分子的自交换是否可以通过连接它们的桥来控制？ 一种动力学方法，使氧化还原平衡在绝热/非绝热边界被量化的第一次被利用。 通过脉冲光激发或外加电位引发所需的电子转移化学反应，并通过原位光谱电化学、吸收各向异性、计时光散射和瞬态吸收光谱进行量化。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

In this project, funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division, Professor Gerald Meyer of the Department of Chemistry at the University of North Carolina at Chapel Hill is characterizing intermolecular electron transfer reactions for molecules anchored to metal oxide surfaces. The goal of this research is to exploit self-exchange reactions as a means to transport charge across oxide surfaces for applications in optoelectronic devices, namely for the conversion of solar energy into stored chemical energy or electricity (e.g. dye-sensitized solar cells). The project lies at the interface of physical organic, inorganic, and materials chemistry, and is therefore well suited to the education of scientists at all levels. This group is also well-positioned to provide the highest level of education and training for students underrepresented in science. Outreach activities to grade school students in local and rural North Carolina are also part of the funded project. Research has shown that photo-oxidized dye molecules anchored to the sensitized mesoporous nanocrystalline (anatase) TiO2 thin films commonly used for dye-sensitized solar cells undergo self-exchange intermolecular electron transfer reactions (termed hole-hopping) with dynamics and efficiencies that can be tuned at the molecular level. These findings provide an opportunity to transport charges to desired locations without a loss in Gibbs free energy. Particular focus wiis being given to address the following fundamental questions: How can molecular structure be tuned to control intermolecular electron transfer? Is there a correlation between self-exchange reactions in fluid solution and those on oxide surfaces? Does self-exchange electron transfer between dyes influenced unwanted recombination reactions? Can self-exchange with molecules that contain two (or more) redox active groups be controlled by the bridge that links them? A kinetic approach that enables redox equilibria at the adiabatic/non-adiabatic border to be quantified for the first time is being utilized. The desired electron transfer chemistry is being initiated by pulsed light excitation or with an applied potential and quantified by in situ spectro-electrochemistry, absorption anisotropy, chronoabsorptometry, and transient absorption spectroscopy.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.