International Collaboration in Chemistry: Exploring and Controlling the Reactivity of Endohedral Fullerenes

技术摘要：在国际化学合作（ICC）计划和NSF大分子，超分子和纳米化学计划的支持下，来自德克萨斯大学埃尔帕索分校的Echegoyen教授和来自西班牙的Martin，Poblet和托雷斯教授将合成，分离和表征一系列具有高度不寻常电子特性的新富勒烯衍生物。一些新的衍生物将拥有一个或多个连接到内嵌富勒烯表面的五元环上的二茂铁或二茂基团，从而产生有史以来第一个报道的内嵌巴基碳烯。电子之间的耦合exo和内金属物种将被测量和分析。这些新化合物的性质将使用各种各样的技术，特别是电化学，寻找内外相互作用及其与整体性质的关系进行充分表征。在第二个项目中，将制备基于新设计的卟啉和酞菁连接体的一系列新的共价有机框架（COF），以努力获得具有相对大的孔径的COF。将富勒烯纳入这些COF孔内的能力将用各种技术来探测，以尝试评估供体-受体（D-A）相互作用是否存在以及它们有多强。富勒烯，也称为“Buckyballs”，是一种全碳化合物，具有独特的和有些不寻常的电子特性，使它们在许多应用中非常有用，例如太阳能电池。它们是封闭的碳结构（只有60个碳的结构与足球相同），并且能够在其表面进行化学反应。将其他物质包裹在其中的富勒烯，例如其他原子的簇，被称为内嵌富勒烯，这些具有非常有趣和独特的电子特性。许多反应已被用于功能化的富勒烯的表面，无论是空的，以及内嵌的，但一些独特的将在本工作中探索，特别是对内嵌化合物。将对所得化合物进行表征，并测量其性能，特别是在太阳能光化学中的潜在应用。除了直接的教育经验和指导提供给参与这个项目的本科生和研究生，这个项目的最深远的更广泛的影响来自美国首席研究员（PI）在他的实验室招募和教育代表性不足的少数民族的承诺。PI积极招募波多黎各和其他西班牙裔和少数民族学生到他的实验室，他的22名博士毕业生中有14名是西班牙裔。除了积极指导代表性不足的少数民族学生（主要是西班牙裔），该项目涉及与西班牙三个不同的研究小组非常强大的国际合作，两个是综合导向，一个理论。PI在这两个更广泛的影响领域有着悠久而富有成果的历史，预计这些将在目前的补助金下继续下去。

TECHNICAL SUMMARY:With support from the International Collaboration in Chemistry (ICC) Program and the Macromolecular, Supramolecular, and Nanochemistry Program of the NSF, Professor Echegoyen from the University of Texas-El Paso and Professors Martin, Poblet and Torres from Spain will synthesize, isolate, and characterize a series of new fullerene derivatives with highly unusual electronic properties. Some of the new derivatives will possess one or more attached ferrocene or ruthenocene groups to five-membered rings on the surface of endohedral fullerenes, to yield the first endohedral buckymetallocenes ever reported. Electronic coupling between the exo- and endohedral metal species will be measured and analyzed. The properties of these new compounds will be fully characterized using a wide variety of techniques, especially electrochemistry, looking for endo-exo interactions and their relationship to the overall properties. In a second project, a new series of Covalent Organic Frameworks (COFs) based on newly designed porphyrins and phthalocyanine linkers will be prepared, in an effort to obtain COFs with relatively large pore sizes. The ability to incorporate fullerenes inside these COF pores will be probed with a variety of techniques to try to assess if Donor-Acceptor (D-A) interactions exist and how strong they are. NON-TECHNICAL SUMMARY:Fullerenes, also called 'Buckyballs' are all-carbon compounds with unique and somewhat unusual electronic properties that make them useful in many applications, for example in solar cells. They are closed carbon structures (the one possessing only 60 carbons is identical to a soccer ball) and are capable of undergoing chemical reactions on their surfaces. Fullerenes that encapsulate other species inside, such as clusters of other atoms, are called endohedral fullerenes, and these have very interesting and unique electronic properties. Many reactions have been used to functionalize the surfaces of fullerenes, both empty as well as endohedral, but some unique ones will be explored in the present work, especially on the endohedral compounds. The resulting compounds will be characterized and their properties measured, specifically looking at potential applications in solar photovoltaics. Besides the immediate educational experience and mentoring provided to the undergraduate and graduate students involved in this project, the most profound broader impact of this project derives from the commitment of the US Principle Investigator (PI) to recruit and educate underrepresented minorities in his laboratories. The PI actively recruits Puerto Rican and other Hispanic and minority students to his labs as evidenced by the fact that 14 of his 22 PhD graduates have been Hispanic. In addition to actively mentoring underrepresented minority students (Hispanics primarily), this project involves very strong international collaborations with three different research groups in Spain, two being synthetically oriented and one theoretical. The PI has a long and fruitful history in both of these broader impact areas and these are expected to continue under the present grant.