Electron Transfer Photooxygenations With New and Improved Electron Transfer Sensitizers in Homogeneous and Heterogeneous Media

通过这一奖项，有机和高分子化学项目支持了怀俄明大学的爱德华·L·克伦南教授的工作。这项研究将研究一系列新的捕光分子的合成和表征，这些分子携带两个正电荷，对于这些正电荷，人们建议将其称为吡咯烷酮。这两个正电荷作为一种独特和关键的结构特征被结合到这些新材料中，旨在作为高效的光化学引发电子转移(PET)催化剂提供优异的性能。与其他PET催化剂不同的是，从底物到这些吡喃的电子转移会产生两个相斥的正电荷物种，这两个物种将迅速分离，从而防止能量浪费回电子转移。初步研究表明，这些分子吸收的光与太阳光谱非常相似，并且具有优异的光学特性，可以在不被基质竞争吸收的情况下进行激发。我们将研究它们的光化学性质和电化学性质。此外，这些新材料作为电子转移催化剂在将氧引入有机分子中的有效性将被证明。这些新材料还将被嵌入到惰性基质中，以生成稳定的多相催化剂，这些催化剂可以在其他不相容的环境中使用。更广泛的影响。光化学引发的电子转移(PET)反应是一类广泛的基本转化，因此，这些新材料的开发具有深远的影响，远远超出了本提案中描述的用途。它们的使用将代表着朝着设计更环保的工艺迈出的积极一步，这些工艺将允许获得新的、否则无法获得的产品。由这些材料衍生的多相催化剂有望作为光催化剂用于污染废水的修复，因为预计它们将具有降解和矿化有机污染物的功能。最后，该项目将为培训学生提供一个杰出的工具，这些学生将加强科学工作队伍。

With this award, the Organic and Macromolecular Chemistry Program supports the work of Professor Edward L. Clennan of the University of Wyoming. This research will investigate the synthesis and characterization of a series of new light harvesting molecules that carry two positive charges for which the word pyrylogens has been suggested. The two positive charges have been incorporated in these new materials as a unique and key structural feature designed to provide superior performance as efficient photochemically initiated electron transfer (PET) catalysts. In contrast to other PET catalysts, electron transfer from a substrate to these pyrylogens will generate two repulsive positively charged species that will rapidly separate thereby preventing energy wasting back electron transfer. Preliminary studies have demonstrated that these molecules absorb light that closely mimics the solar spectrum and have superior optical properties that will allow excitation without competitive absorption by the substrates. Both their photochemical and electrochemical properties will be investigated. Further, the effectiveness of these new materials as electron transfer catalysts to introduce oxygen into organic molecules will be demonstrated. These new materials will also be imbedded in an inert matrix to generate stabilized heterogeneous catalysts that can be used in otherwise incompatible environments. Broader Impacts. Photochemically initiated electron transfer (PET) reactions are a broad fundamental class of transformations and as a consequence, the development of these new materials has far reaching impact well beyond the uses described in this proposal. Their use will represent a positive step toward the design of "greener" environmentally friendly processes that will allow access to new, otherwise inaccessible products. The heterogeneous catalysts derived from these materials have potential use as photocatalysts for the remediation of polluted wastewater since it is anticipated that they will function to degrade and mineralize organic pollutants. Finally, this project will provide an outstanding vehicle for the training of students who will enhance the scientific workforce.