New Synthetic Routes to Well-Defined Nanocarbon Materials

在美国国家科学基金会化学部大分子、超分子和纳米化学项目的支持下，T。加州大学伯克利分校的Don蒂利正在探索制备大尺寸多环芳烃（PAH）的合成路线，PAH代表了分子纳米碳材料家族。 石墨烯是一种扩展的二维纳米碳材料，因其有趣的电子特性而闻名;然而，其结构是不规则的，这使其在纳米电子器件中的应用变得复杂。 相比之下，所研究的多环芳烃具有明确的分子结构，具有石墨烯样的电子性质。 该项目旨在提供有关特定分子结构特征对所需电子特性影响的基础知识。 该项目预计将影响纳米科学领域，特别是碳基半导体有机材料作为量子信息科学，通信和传感等领域紧急应用组件的可用性。 在进行这项研究的过程中，参与的学生将接受先进的有机合成和材料表征技术的培训。 相关的外联活动包括参加加勒比国家联盟的“经济困难者暑期体验”项目和针对小学生的“伯克利湾区科学家在校方案”，该项目开发合成方法，以便在有控制地建造大型、定制的多环芳烃时有效地引入多个稠合芳环。这是通过高产率的[2+2+n]环加成来实现的，该环加成在单个合成步骤中产生多个稠合芳环。可扩展的反应用于获得广泛的新的碳纳米结构，包括螺旋烯，纳米带，环芳烃和纳米带。一个特定的目标是一个家庭的扩大，螺旋多环芳烃的主客体化学和偏振光相互作用的背景下进行研究。其他目标包括大环多环芳烃和它们的组装通过超分子相互作用的方式，和细长的，nanoriginal结构，预计表现出作为一维半导体的性能。代表碳纳米管的分子切口的纳米带结构正在合成和研究中。另一个兴趣是开发将多环芳烃连接在一起以形成定义明确的扩展结构的策略，这些结构有助于弥合碳同素异形体的自下而上有机合成和自上而下合成之间的差距。该研究旨在首先从基础角度了解新型纳米碳材料的行为，然后（作为一个长期目标）利用合成的模块化来合理调整结构，以实现有机电子学和量子信息科学（QIS）中的预期应用该奖项反映了NSF的法定使命，并通过使用基金会的智力价值进行评估，更广泛的影响审查标准。

With the support of the Macromolecular, Supramolecular, and Nanochemistry Program in the Division of Chemistry at the National Science Foundation, Professor T. Don Tilley of the University of California, Berkeley is exploring synthetic routes to prepare large-sized polycyclic aromatic hydrocarbons (PAHs), which represent a family of molecular nanocarbon materials. Graphene, an extended two-dimensional nanocarbon material, is well known for interesting electronic properties; however, its structure is irregular, which complicates its utility in nanoelectronic devices. In contrast, the PAHs under investigation exhibit well-defined molecular structures with graphene-like electronic properties. The project is geared toward providing fundamental knowledge regarding the effect of specific molecular structural features on desired electronic properties. The project is expected to impact the field of nanoscience, and especially the availability of carbon-based semiconducting organic materials as components for emergent applications in areas such as quantum information science, communications, and sensing. During the course of conducting this research, the students involved will be trained in advanced organic synthesis and material characterization techniques. The associated outreach activities include participation in the ACS Summer Experiences for the Economically Disadvantaged (SEED) Project and the Bay area scientists in school at Berkeley (BASIS) Program targeting elementary school students.The project develops synthetic methodologies for the efficient introduction of multiple fused aromatic rings in the controlled construction of large, tailored polycyclic aromatic hydrocarbons (PAHs). This is accomplished with high yielding [2+2+n] cycloadditions that produce multiple fused aromatic rings in a single synthetic step. The scalable reactions are used to access a wide range of new carbon nanostructures, including helicenes, nanobelts, cycloarenes, and nanoribbons. A specific target is a family of expanded, helical PAHs that are to be studied in the context of host-guest chemistry and interactions with polarized light. Other targets include macrocyclic PAHs and their assembly by way of supramolecular interactions, and elongated, nanoribbon structures expected to exhibit properties as 1-dimensional semiconductors. Nanobelt structures that represent molecular cut-outs of carbon nanotubes are being synthesized and studied. An additional interest is development of strategies for linking the PAHs together to form well-defined, extended structures that help bridge the gap between bottom-up organic synthesis and top-down synthesis of carbon allotropes. The research aims to first understand the behavior of new nanocarbon materials from a fundamental perspective, and then (as a longer-term goal) take advantage of the modularity of the syntheses to rationally tune structures for desired applications in organic electronics and quantum information science (QIS).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.