Supramolecular Structures Incorporating Fullerene Derivative Linkers

技术概要：在NSF的大分子，超分子和纳米化学计划的支持下，这些研究人员将合成，分离和表征一系列新的富勒烯衍生物，这些衍生物将用于构建新的超分子结构。新的衍生物将是来自C60的区域异构纯化合物，具有双官能度和四官能度，这样它们就可以通过与特定和精心选择的金属离子的自发组装形成2D和3D结构。从简单的三角形和正方形到3D立方体，甚至更复杂的结构都将被制备出来，每个结构都含有富勒烯作为内在的连接体成分。这种结构以前从未报道过，特别是含有富勒烯作为连接单元。这些超分子化合物的性质将得到充分的表征。在第二个项目中，将首次使用电弧放电技术合成和表征其他富勒烯化合物，主要是由不同碳笼大小组成的内嵌富勒烯系统，其中包含各种原子簇。虽然我们已经并将继续研究三金属氮化物内面体系统（TMN），但本申请特别关注在前一个授权期间发现的相对较新的内面体家族，即相对丰富的二金属硫化物（DMS），M2S@C2n（M=Sc和40n48）。将制备这些硫化物化合物的混合金属版本，其中内部的两种金属将不同，以尝试识别以高产率生产的不同笼尺寸。以下金属将被纳入一个二元的方式，M=Sc，Y，Lu，Dy，Ho，Gd，Nd，和Pr。这些新的化合物的电化学性能将被测量，因为它已被证明，这些内生系统中的一些具有潜在的用途作为受体在光伏器件。这些新的化合物的exohedral化学也将进行研究，特别是在regiochemistry的多个添加和其潜在的相关性的结构和取向的内面体集群（内外面体模板相关性）。最后一个领域的建议涉及非常基础的研究电子和自旋本地化的还原和氧化的内生化合物。由于电化学和ESR光谱学的数据有些矛盾，我们将尝试对几种内嵌富勒烯进行电结晶，以通过X射线晶体学来表征这些系统。非技术概要：富勒烯，也称为“巴基球”，是一种全碳化合物，具有独特的和有些不寻常的电子性质，使它们在光电子学等应用中非常有用。它们是封闭的碳结构（有60个碳的结构与足球相同），能够在其表面进行化学反应。在这项工作中将解决的问题之一是如何控制将添加到表面的化学基团的确切位置，因为缺乏控制会导致制备太多不同的化合物（异构体）。限制异构体的数量以仅获得所需的化合物是这项工作的目标的一部分。 一旦制备好，新的衍生化合物将被纳入更复杂的结构中，主要使用金属离子来自发地诱导它们的形成。将对这些结构进行表征并测量其性能。除了空的碳笼富勒烯之外，还将制备新的内嵌衍生物，其包含包封在笼中的金属和非金属原子，如分子沙球。其目的是改变和控制未来潜在光伏应用的电子特性。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，研究生和博士后同事，这个项目的最深远的影响来自PI的承诺，招募和教育在他的实验室代表性不足的少数民族。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（主要是西班牙裔学生），PI还积极参与国际合作，主要是与西班牙和德国合作，并与他们一起广泛出版，这一点从他的传记素描中可以看出。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 Macromolecular, Supramolecular, and Nanochemistry Program of the NSF these researchers will synthesize, isolate, and characterize a series of new fullerene derivatives that will be used in the construction of new supramolecular architectures. The new derivatives will be regioisomerically pure compounds derived from C60 with bis- and tetra-functionalities arranged so that they can form 2D and 3D architectures via spontaneous assembly with specific and carefully selected metal ions. Architectures ranging from simple triangles and squares to 3D cubes and even more complex ones will be prepared, each containing fullerenes as intrinsic linker components. Such structures have never been reported before, especially containing fullerenes as linker units. The properties of these supramolecular compounds will be fully characterized. In a second project, other fullerene compounds will be synthesized and characterized for the first time using arc discharge techniques, mainly endohedral fullerene systems consisting of different carbon cage sizes containing a variety of atom clusters inside. While we have worked and will continue to work with trimetallic nitride endohedral systems (TMNs) this application focuses particular interest in a relatively new family of endohedrals discovered during the previous grant period, the dimetallic sulfides DMSs), M2S@C2n (M=Sc, and 40n48), which are relatively abundant. Mixed metallic versions of these sulfide compounds will be prepared where the two metals inside will be different, in an effort to try to identify different cage sizes that are produced in high yields. The following metals will be incorporated in a binary fashion, M=Sc, Y, Lu, Dy, Ho, Gd, Nd, and Pr. The electrochemical properties of these new compounds will be measured since it has been shown that some of these endohedral systems have potential uses as acceptors in photovoltaic devices. The exohedral chemistry of these new compounds will also be investigated, specifically looking at the regiochemistry of multiple additions and its potential correlation to the structure and orientation of the endohedral clusters (endo-exohedral templating correlations). One final area proposed involves very fundamental studies of electron and spin localization in reduced and oxidized endohedral compounds. Electrocrystallization of several of these endohedral fullerenes will be attempted in order to characterize the systems by X-Ray crystallography since data from electrochemistry and ESR spectroscopy are somewhat in contradiction.NON-TECHNICAL SUMMARY: Fullerenes, also called "Buckyballs" are all-carbon compounds with unique and somewhat unusual electronic properties that make them useful in applications such as photovoltaics. They are closed carbon structures (the one with 60 carbons is identical to a soccer ball) capable of undergoing chemical reactions on their surfaces. One of the problems that will be addressed in this work is how to control the exact positions of the chemical groups that will be added to the surface, since lack of control leads to the preparation of too many different compounds (isomers). Limiting the number of isomers to obtain only the desired compounds is part of the aim of this work. Once prepared, the new derivative compounds will be incorporated into more complicated structures using mainly metal ions to induce their formation spontaneously. These structures will be characterized and their properties measured. In addition to empty carbon cage fullerenes, new endohedral derivatives will be prepared which contain metallic and non-metallic atoms encapsulated in the cages, like molecular maracas. The purpose is to vary and control the electronic properties for potential photovoltaic applications in the future. Besides the immediate educational experience and mentoring provided to the undergraduate, graduate and postdoctoral associates involved in this project, the most profound broader impact of this project derives from the commitment of the 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), the PI is heavily involved in international collaborations, mainly with Spain and Germany and publishes extensively with them, as evident from his biographical sketch. 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.