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

技术总结：在国际化学合作项目（ICC）和美国国家科学基金会大分子、超分子和纳米化学项目的支持下，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Torres教授将合成、分离和表征一系列具有高度不寻常电子性质的新型富勒烯衍生物。一些新的衍生物将在内嵌富勒烯表面的五元环上具有一个或多个二茂铁或钌二茂基团，从而产生迄今为止报道的第一个内嵌巴克基茂金属。将测量和分析外腔和内腔金属之间的电子耦合。这些新化合物的性质将利用各种各样的技术，特别是电化学，寻找内外相互作用及其与整体性质的关系来充分表征。在第二个项目中，将基于新设计的卟啉和酞菁连接剂制备一系列新的共价有机框架（COFs），以获得孔径相对较大的COFs。将富勒烯纳入这些COF孔中的能力将通过各种技术进行探测，以试图评估供体-受体（D-A）相互作用是否存在以及它们的强度。非技术概述：富勒烯，也被称为“巴基球”，是一种全碳化合物，具有独特的，有些不寻常的电子特性，使其在许多应用中都很有用，例如在太阳能电池中。它们是封闭的碳结构（一个只有60个碳的结构和一个足球一样），并且能够在它们的表面发生化学反应。将其他物质包裹在里面的富勒烯，比如其他原子簇，被称为内嵌式富勒烯，它们具有非常有趣和独特的电子特性。许多反应已经被用来功能化富勒烯的表面，无论是空的还是内嵌的，但一些独特的反应将在本工作中进行探索，特别是在内嵌化合物上。所得到的化合物将被表征并测量其性能，特别是在太阳能光伏发电方面的潜在应用。除了为参与该项目的本科生和研究生提供直接的教育经验和指导外，该项目最深远的广泛影响来自美国首席研究员（PI）在其实验室中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）外，该项目还涉及与西班牙三个不同的研究小组的强有力的国际合作，其中两个是综合导向的，一个是理论导向的。PI在这两个更广泛的影响领域有着悠久而富有成效的历史，预计这些将在本赠款下继续下去。

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.