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

技术摘要：在国际化学合作(ICC)计划和美国国家科学基金会的大分子、超分子和纳米化学计划的支持下，德克萨斯大学埃尔帕索分校的Echegoyen教授和西班牙的Martin、Poblet和Torres教授将合成、分离和表征一系列具有非常不寻常的电子性质的新富勒烯衍生物。一些新的衍生物将在面体内富勒烯的表面上将一个或多个二茂铁或茂铁基团连接到五元环上，从而合成第一个报道的面体内巴克茂金属化合物。将测量和分析面外和面内金属物种之间的电子耦合。这些新化合物的性质将利用广泛的技术，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全面表征。在第二个项目中，将制备一系列新的基于新设计的卟啉和酞菁连接物的共价有机骨架(COF)，以努力获得相对大的孔尺寸的COF。在这些COF孔中结合富勒烯的能力将被用各种技术来探索，以试图评估是否存在供体-受体(D-A)相互作用以及它们的强度。非技术摘要：富勒烯，也被称为“巴克球”，是一种全碳化合物，具有独特的、有点不寻常的电子性质，使它们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(只有60个碳的结构与足球相同)，能够在其表面发生化学反应。包裹了其他物种的富勒烯，如其他原子簇，被称为内面体富勒烯，这些具有非常有趣和独特的电子性质。许多反应已经被用来功能化富勒烯的表面，包括空体和面体内的，但本工作将探索一些独特的反应，特别是面体内的化合物。将对合成的化合物进行表征，并测量其性能，特别是在太阳能光伏领域的潜在应用。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，该项目最深远的更广泛的影响来自美国首席调查员(PI)在其实验室招募和教育未被充分代表的少数民族的承诺。PI积极招募波多黎各人和其他拉美裔和少数族裔学生到他的实验室，这一事实证明了他的22名博士毕业生中有14名是西班牙裔。除了积极指导少数族裔学生(主要是西班牙裔)外，该项目还与西班牙的三个不同的研究小组进行了非常强有力的国际合作，其中两个是综合研究小组，一个是理论研究小组。在这两个更广泛的影响领域，私营部门倡议有着悠久而卓有成效的历史，预计在目前的赠款下，这些影响将继续下去。

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.